Wine & Viticulture Journal Spring 2023

SPRING

• Maturation: have the options improved?

• Aerial spraying of vineyards - never say never!

• Alternative packaging - should we move beyond the green bottle?

• Tasting: Field blend whites and other white blends

INDUSTRY ASSOCIATION COLUMNS

10 AGW / WINE AUSTRALIA: :One Sector Plan to get us back on track

11 ASVO (Andy Clarke): New editor in chief for the Australian Journal of Grape and Wine Research

WINEMAKING

12 RACHEL GORE: Maturation recap: have the options improved?

18 Understanding the effect of barrel-to-barrel variation on the colour and phenolic composition of a red wine

22 Consumer response to wine made from smoke-affected grapes

28 AWRI REPORT: Vintage 2023 - observations from the AWRI helpdesk

VITICULTURE

42 Aerial spraying of vineyards - why you never say never!

48 Advances in grapevine viral disease detection: use of optical imaging technology for virus surveillance in vineyards?

53 Managing botrytis sustainably: investigations of dsRNA silencing technology

54 Frost - causes and mitigation strategies for established vineyards

59 Future success in wine industry growth and sustainability relies on improved plant material

64 How does a variable and changing climate impact budburst timing of winegrapes?

67 ALTERNATIVE VARIETIES: Savagnin

BUSINESS & MARKETING

70 TOWARDS NET ZERO: Alternative packaging and wine: should we move beyond the green bottle?y

74 The journey to better understanding the direct-to-consumer channel

76 Top-line results from Vintage 2023

80 The consumer preference for lower alcohol: are there lessons from beer?

TASTING

88 Field blend whites, and other white blends

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Leigh Francis

Lucy Golding

Rachel Gore

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As I write this editorial (late August), a series of workshops are being held around the country giving members of the Australian wine industry the opportunity to identify the collective challenges facing the sector and how they might be addressed. That feedback will be used to formulate strategies for a One Sector Plan (OSP), which is being jointly led by Australian Grape & Wine and Wine Australia in acknowledgement of the “perfect storm of issues” that have impacted the sector since 2020 and are being “felt by everyone in the community”.

Members of industry are also encouraged to complete a short online survey to put forward their thoughts on which of the following themes the plan should focus on: people, consumers, customers and communities, product and place, environmental, social and governance (ESG), markets or systems.

A draft OSP is expected by December 2023. In a joint column, Wine Australia CEO Martine Cole and Australian Grape and Wine CEO Lee McLean speak more about the One Sector Plan which you can find on page 10.

Underlining the challenges facing the industry that the OSP aims to address are the figures from the 2023 vintage (which Peter Bailey from Wine Australia takes a deep dive into on page 76) and the export stats from the 2022-23 financial year (see page 7).

Also in this issue of the Wine & Viticulture Journal, we present the fourth and final article in our Towards Net Zero series. With packaging and transport being such a significant contributor to the wine industry’s emissions, we asked the Australian Wine

Research Institute to compare the carbon footprint of different packaging options, and the technical considerations that producers should bear in mind when weighing them up.

Sticking with the theme of climate change, over in Viticulture, we are celebrating the return of former regular writer Tony Hoare who from this issue onwards will be providing a series of articles on managing extreme weather events. In keeping with the season, Tony’s first article takes a look at frost (page 54). Then we have researchers from the University of Newcastle revealing the results of their investigations into the influence of changing springtime temperatures on budburst across Australia’s wine regions (page 64).

With extreme weather events, such as fires, forecast to become more frequent and intense due to climate change, information to help guide producers on what to do with grapes that have been exposed to smoke from a nearby fire is paramount. While there has been significant inroads into understanding whether or not and to what degree a wine exposed to smoke will be smoke-affected, there has been little research into exactly how consumers perceive these wines. The AWRI has undertaken some research into the consumer acceptance of smoke characters in wine and present them in an article in Winemaking which starts on page 22.

Also in Winemaking, our regular scribe Rachel Gore reviews current methods for maturing wine, balancing their quality outcomes against their price (see page 12).

Enjoy delving into these articles and more in the following pages.

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Cover image: Wine Australia

INDUSTRY STATISTICS

2023 DELIVERS SMALLEST VINTAGE IN A GENERATION

The Australian wine industry crushed an estimated 1.32 million tonnes in 2023, 26 per cent less than the 10-year average and the lowest recorded since 2000, according to the latest national vintage report released by Wine Australia.

Wine Australia manager, market insights, Peter Bailey, said the second consecutive smaller vintage would have a direct impact on grape and wine businesses.

“This smaller vintage, which will reduce the wine available for sale by around 325 million litres, is likely to have a considerable impact on the bottom line of grape and wine businesses all around Australia, at a time when the costs of inputs, energy, labour and transport have increased significantly.”

Bailey said a third consecutive La Niña event produced the wettest year since 2011 and it was also Australia’s coolest year since 2012. Persistent winter and spring rainfall across much of South-Eastern Australia made access to vineyards difficult as well as causing flooding in some regions. The cool, wet conditions through spring and summer in some regions also led to lower yields, delayed ripening and challenges managing disease.

Further reducing the size of the crush were winery inventory pressures resulting in some yield caps being imposed, uncontracted grapes not being sold and/or vineyards being temporarily taken out of production.

Bailey said that it was impossible to determine what share of the overall reduction, compared with an average vintage, could be attributed to demand-driven effects as opposed to seasonal conditions.

“However, white grapes — which are in higher demand — were reduced by a similar percentage to reds, which suggests that seasonal effects were the main contributor to the reduction,” Bailey said.

The crush of red grapes in 2023 is estimated to be 711,777 tonnes — a 26 per cent reduction compared with 2022 and 25% below the 10-year average of 943,146 tonnes, while the white crush was an estimated 605,321 tonnes — a decrease of 22% compared with 2022 and 28% below its 10-year average of 839,013 tonnes.

South Australia retained its position as the largest contributor to the crush, with a 55% share of the total, despite its second-smallest crush since 2007. New South Wales was second-largest with 27% of the crush, followed by Victoria with 13%. Western Australia, which overall had a very good season, increased

its share to 3.5%, while Tasmania and Queensland each accounted for slightly less than 1%.

The main reduction in the crush came from the three large inland wine regions: the Riverland (South Australia), Murray DarlingSwan Hill (New South Wales and Victoria) and Riverina (New South Wales). The crush from these regions combined was down 28% per cent to 899,936 tonnes, whereas the crush from the rest of Australia’s 59 GI wine regions and 26 GI zones together was only down by 15% compared with 2022 at 417,162 tonnes. This meant that the large inland regions reduced their share of the national crush to 68 per cent, compared with the long-term average of 74 per cent.

The total estimated value of the 2023 crush at the weighbridge was $983 million, a decrease of $229 million (19%) compared with the 2022 vintage and the lowest since 2015. The decline in value was less than the decline in tonnes, because of a small increase in the overall average purchase value, driven by an increase in the average value and share of grapes from cool-temperate regions.

EXPORT VALUE CONTINUES DECLINE AS GLOBAL WINE MARKET WEAKENS

Australian wine exports declined by 10 per cent in value to $1.87 billion and 1% in volume to 621 million litres in the year ended June 2023, according to Wine Australia’s latest Export Report.

The decline in value was largely driven by a reduction in exports to the United States of America (US) as lower-priced packaged exports continued to decline. Exports to the United Kingdom (UK) also continued to decline, following the two years of elevated shipments due to pre-Brexit demand and COVID-19 related market impacts.

The latest export results are partially reflective of broader global trends reported by market research firm IWSR, with all wine consumption globally declining 3% in volume in 2022, but premium price segments bucking the trend with continued growth, albeit at slower rates than recent years.

Wine Australia manager, market insights, Peter Bailey said that more than half of the decline in Australia’s export value took place in shipments with an average value between $2.50 to $4.99 per litre free on board (FOB), which are generally wines exported in their final packaging and sold in lower priced retail segments.

“Wine consumption in mature markets is in decline, driven by decreases in the commercial price segments. This is impacting Australia’s export performance, especially in the US, as Australia is very exposed to the price segments in decline,” Bailey said.

In comparison to value, export volume was stable as a short-term, supply driven increase in unpackaged wine shipments, especially to Canada, was outweighed by declines in volume to many of Australia’s export destinations.

“The growth in unpackaged shipments comes as the shipping challenges of the past couple years have eased, allowing Australian exporters to catch up and ease pressure on inventory,” Bailey said.

The complete report can be downloaded at www.wineaustralia.com/market-insights/ australian-wine-export-report

INDUSTRY OUTLOOK

AUSTRALIAN WINE INDUSTRY ‘SWIMMING IN WINE’

Immediate removal of Chinese antidumping tariffs would not be enough to prevent Australia’s wine industry facing several years of oversupply, according to Rabobank’s Wine Quarterly Q3 2023 report.

Improving trade relations between China and Australia the recent removal of Chinese tariffs on Australian barley has led to hope that

removal of the tariffs placed on Australian wine in March 2021 may be imminent.

However, the report by Rabobank, a leading specialist in food and agribusiness banking, says even in a “best case scenario”, with tariffs removed this year and Chinese consumption of Australian wine recovering quickly, this would “not be a panacea”, with Australia’s wine industry still facing at least two years to work through its current wine surplus.

Report author, RaboResearch associate analyst Pia Piggott, said so large is the current oversupply, that Australia has the equivalent of 859 Olympic swimming pools worth of wine in storage.

“That’s over two billion litres of wine, or over 2.8 billion bottles of the wine,” she said.

Piggott said that when a slew of Chinese anti-dumping tariffs and soft bans hit various products exported by Australia in 2020-21, wine took the most notable hit, losing about one third of export value from its peak in 2019,” she said.

“Unluckily, the tariff coincided with an exceptional growing season and Australia’s largest crush on record.

“Wine production for the ’21 vintage increased 36 per cent year on year, which would have in any case caused an oversupply. This coincided with COVID, logistics bottlenecks and inflation which were major hurdles in the way of plans to grow and diversify exports. Thus, two plus years into the tariff, prices of Australian commercial red grapes have significantly declined, and oversupply issues remain,” she said.

Piggott highlighted that the wine market in China has been contracting in recent years, with consumption more than halving from its peak in 2017 to just 880 million litres in 2022.

“Chinese consumers began transitioning away from wine as part of a broader decline in alcohol consumption on a per capita basis, however declines were greater for wine than beer and spirits,” she said.

“COVID lockdowns and the economic slowdown curbing discretionary spending have also played a role in declining consumption to levels not seen since the 1990s. Despite only Australia being hit by tariffs, the past five years has seen volume declines in imports from nine of the top ten supplying countries, as consumers become more price sensitive.”

Rabobank projects that China’s consumption reached the bottom in 2022, and while there is considerable uncertainty, there is upside potential for growth in imports as ontrade premises reopen and the urban middle class have more disposable income to spend wining and dining.

“Positively, some Australian brands have maintained brand awareness and presence on retail shelves in China throughout the tariff period by expanding their range of products from origins outside Australia,” she said.

The Rabobank report said despite competitive pricing, a valuable brand and quality product, it has been difficult for Australia to grow total exports in the absence of the Chinese market over the last few years.

“In a push to move volume, bulk wine has grown from 55% pre-tariff to over 60% of exports and as long as stocks need to be shifted as bulk shipments, prices will remain depressed,” Piggott said.

“In the United Kingdom, Australian imports have fallen from their peak in 2020 as off premise consumption of wine declines following COVID reopening.

“In the United States bulk wine has grown to represent 25% of imports from Australia, with increasing volumes and declining average value,” she said.

“In 2023 and onwards we expect the UK and US will remain key export markets for Australian wine, however some headwinds remain. In the UK, implementation of new alcohol duty rates will increase duties payable on a typical bottle of Australian wine by 20 per cent (750ml at 12.5 per cent alcohol).”

The Rabobank report said the Australian wine market will remain in oversupply for a considerable length of time.

“To return to balance and profitability, acreage needs to be reduced, thus over the next five years we will see rationalisation of assets throughout the supply chain,” it said.

Piggott said for vineyards, margin pressure from both ends will remain high for some time, particularly for uncontracted vineyards with a high mix of red varieties.

“For wineries, particularly those selling commercial wine, stocks will remain high for some time as businesses slowly work through selling inventory. While some brands have increased bulk shipments and been able to heavily discount stock, this will need to continue for some time to rebalance the market,” she said.

PESTS & DISEASES

SA ACCEPTS MORNINGTON PENINSULA AS A PHYLLOXERA EXCLUSION ZONE

South Australia’s Department of Primary Industries and Regions (PIRSA) has reclassified the Mornington Peninsula as a Phylloxera Exclusion Zone (PEZ) from a Phylloxera Risk Zone (PRZ) for the purposes

of imports into the state, Vinehealth Australia announced to industry this morning.

Entry requirements for regulated phylloxera risk vectors from the Mornington Peninsula have therefore changed according to South Australia’s Plant Quarantine Standard.

The Victorian Government gazetted the Mornington Peninsula as a PEZ in March 2022. PIRSA’s recognition of the region as a PEZ brings South Australia into line with other states and territories.

Vinehealth is mandated under the Phylloxera and Grape Industry Act 1995 to assess the relative threat to South Australia’s vineyards posed by phylloxera and has been encouraging PIRSA to place a moratorium on endorsing the upgrade of any Phylloxera Management Zone until the completion of a review into the National Phylloxera Management Protocol (NPMP).

According to Vinehealth, improvements in science have shown that the surveillance, detection, and disinfestation procedures in the National Phylloxera Management Protocol, including the rezoning procedure, are “not sufficiently effective” and are therefore “inadequate as the basis for rezoning to give sufficient confidence in the absence of phylloxera in the surveyed area”. Vinehealth also feels that historical movements between Phylloxera Infested Zones and the Mornington Peninsula are not adequately accounted for.

“The detections of phylloxera in Victorian vineyards this year have further emphasised that there is a considerable delay between time of infection to time of detection, and that detection is difficult,” Vinehealth said in its notice to industry.

“Vinehealth’s and PIRSA’s risk appetites and viewpoints on this decision [to recognise the Mornington PEZ] vary but are both valid,” Vinehealth advised.

“Vinehealth understands there can never be zero biosecurity risk associated with interstate trade, and that many South Australian wine businesses are reliant in some capacity on direct or indirect interstate trade. Therefore, there is a need to balance maintenance of trade with minimising the risk of a pest introduction to the state.

“Given the risks inherent with serious pests such as phylloxera that are difficult to see and detect, slow to show impact in the vineyard, and are spread by a range of vectors — the best protection for all vineyard owners and industry personnel is to ensure your own biosecurity measures are in place.”

COMPANY NEWS

KARADOC WINERY TO CLOSE

Treasury Wine Estate’s commercial winery at Karadoc, near Red Cliffs in the Murray Darling, will close in mid-2024, the company announced in July.

Operating since 1973, the winery currently makes wine for various TWE brands including 19 Crimes, Lindeman’s, Wolf Blass, and Yellowglen. These brands will continue be made with long-standing local TWE winemaking partners Zilzie Wines and Qualia, and at TWE’s Barossa winery in South Australia.

TWE said a number of factors had led to the decision to close its Karadoc winery, including the global decline in commercial wine consumption, rising costs and under-utilised capacity at the site.

“Making the decision to close a site is something we take very seriously and is a last resort after we’ve looked at all other possible options,” said TWE’s chief supply officer Kerrin Petty. “Globally, the wine industry is seeing consumers shift away from commercial wine (less than $10AUD a bottle).

“Over the coming years, we expect commercial volumes at Karadoc to continue to decline and volumes to be at around 60 per cent of the capacity that the site is built to process. Given 70 per cent of costs at Karadoc are fixed, processing less volume means the cost of running the site is substantially higher.

“Combine this with rising costs and unfortunately as a result, we’ve made the difficult decision to close our Karadoc winery from mid-2024, which is hard news to share with our loyal team, the local community and partners.

Approximately 60 TWE workers will be impacted by the closure of the winery.

“We’re committed to assisting our team members to find future employment and continuing to support the local winemaking industry,” Petty said.

The company also plans to divest its commercial vineyards in Lake Cullulleraine, in north-west Victoria, and Yankabilly, in south-west New South Wales.

“We continually review our global vineyard assets to ensure they’re in the best possible places to grow our premium and luxury portfolio,” said Petty.

“A number of factors contribute to our shifting vineyard footprint including changing consumer trends and wine preferences as well environmental changes such as higher temperatures and reduced access to water.

“This has meant divesting some of our vineyard assets but also looking at opportunities to expand our footprint in new locations for future growth.

“Last year we acquired Beenak Vineyard in Victoria’s Yarra Valley, as well as Château Lanessan in Bordeaux, France, and we hope to share further updates in this space soon,” he said. WVJ

A One Sector Plan to get us back on track

By Dr Martin Cole1 and Lee McLean2

The Australian grape and wine sector is undoubtedly sick of the word ‘unprecedented’, but the perfect storm of challenges facing winegrape and wine producers has frankly never been seen before.

When Australian Grape & Wine developed Vision 2050, in collaboration with Wine Australia, we set out to achieve goals that would be of the greatest benefit to the sector and to the planet — creating a more sustainable, profitable and inclusive grape and wine community.

While the principals of Vision 2050 remain the same, the roadmap to get there has changed significantly. We need to act now to address the immediate challenges of significant wine tariffs, supply chain disruptions and increasing commodity costs.

Wine Australia and Australian Grape & Wine have teamed up to develop the One Sector Plan, a strategy to be co-designed with the sector that identifies the collective challenges facing our sector and how they can be addressed.

To seek everyone’s input on the One Sector Plan, we commissioned ACIL Allen to run a national survey and program of workshops throughout August and September, 2023. While we’re aiming to have a plan drafted by the end of the year, feedback will remain open into the new year to ensure everyone has an opportunity to contribute.

The plan will consider the nuances of different regions and will reflect the organisations’ different roles (including industry-wide advocacy and labour laws), while working together to achieve a collective vision for the broader grape and wine sector.

Workshops are being held across the country so that consultation can be thorough and consider the varying priorities of stakeholders operating in different regions, markets and segments.

Outside of these workshops, we encourage everyone to complete our brief online survey to ensure we have broad representation across Australia’s grape and wine communities.

The co-designed plan will reflect the collective strategic priorities of the sector, recognising the common themes and concerns of growers, makers and exporters, and will have clear objectives about how those concerns can be addressed in the immediate future.

The plan will clearly outline the key challenges and opportunities and provide strategic direction across the sector to provide guidance for the industry to face problems that impact everyone.

While there are differences between the various groups across our sector, there are also key points of collaboration, and the plan will be adaptable to the entire sector’s needs and operating environment.

Navigating different views and priorities naturally has its challenges but we hope to provide alignment on the overall strategic intent of the plan, while allowing for autonomy at local and regional levels.

We encourage anyone who has ideas about how we can face the sector’s challenges to complete the national survey and attend a workshop. The key questions we will be asking in the workshops will explore what the sector’s key priorities are, how those priorities can be addressed through research and innovation, marketing or policyadvocacy; what existing opportunities can be leveraged from existing initiatives, and where the points of collaboration are.

For more information about the One Sector Plan, visit https://www. wineaustralia.com/ one-sector-plan WVJ

Chief Executive Officer, Wine Australia

Chief Executive Officer, Australian Grape & Wine

1

2

New editor in chief for the Australian Journal of Grape and Wine Research

By Andy Clarke, President, Australian Society of Viticulture & Oenology

The Australian Journal of Grape and Wine Research (AJGWR) has a new editor-in-chief following the retirement from the position of long-serving Dr Terry Lee OAM.

Professor Stefano Poni was an outstanding choice for the role. He is an experienced editor, with high integrity, superb judgement and a real affinity with the AJGWR and our purpose. I’m thrilled he will be leading the AJGWR and its talented editorial team.

Professor Poni takes up the role of editorin-chief from Terry Lee who stepped down at the end of June 2023 after a highly successful 11 years in the role.

On behalf of the ASVO board, I’d like to thank Dr Lee who has been an outstanding leader, seeing the AJGWR through considerable change. He has made a tremendous contribution to the publication, the grape and wine community and industry. His pre-eminent publishing achievements led to an all-time high impact factor, and he leaves the AJGWR in strong shape. During his tenure, he upheld the highest quality standards of a leading journal and significantly increased the AJGWR profile and reputation.

Professor Poni is the Professor of Viticulture at the Faculty of Agriculture, Food and Environmental Sciences at the Università Cattolica del Sacro Cuore, Piacenza, Italy. He is also director of the one-year Master VENIT and is coordinator of the Master of Science in Sustainable Viticulture and Enology. He has authored over 320 scientific publications, 159 of which were edited in international refereed journals. His H-index is currently 41 in the Scopus database.

Poni has been an invited speaker at 55 international congresses, he was awarded with the Perdisa Prize in 1994, the ‘Enotecnici’ Prize in 2004, and the Rudolph Hermanns Foundation Prize in 2011. He also won the prize for the best paper published in 2013 in the viticulture section of the American Journal of Enology and Viticulture (AJEV). Poni has been an associate editor for the AJEV since 1 January 2006 and associate editor for the AJGWR since 1 January 2012.

“It is indeed a great honour and privilege

to be appointed as editor-in-chief of the prestigious Australian Journal of Grape and Wine Research,” Poni said. “As a representative of Old World viticulture, the link to Australia as a New World viticulture and oenology leading country is such a stimulating task. My effort will primarily be to attract even more original scientific work about the challenges that the wine chain is facing, starting with climate change-related issues. Moreover, I will try to add further motivation to all actors involved in the process of submission-evaluation-decision for improved interaction between the quality of the selected research and speed of publication.”

ASVO 2023 AWARDS FOR EXCELLENCE

The annual ASVO Awards for Excellence is a prestigious event to promote industry excellence, foster leadership and encourage innovation and sustainability in the Australian wine industry.

The awards have a long and proud history of recognising individuals in the Australian grape and wine community who are champions of change and are willing to go the extra mile to help others.

The Awards for Excellence event includes presentations of the ASVO Viticulturist and Winemaker of the Year, the Wine Science and Technology award, recognition of the best viticulture and oenology papers from the AJGWR, presentation of the Dr Peter May award for most cited paper from the AJGWR in the last five years and an announcement of new ASVO Fellows.

The 2023 awards will be held at the National Wine Centre, Adelaide, on Wednesday 8 November. For more information on this year’s event and to register

visit https://www.asvo.com.au/events/2023awards-excellence

ASVO 2023 AWAC SCHOLARSHIP RECIPIENT

The ASVO board of directors is delighted to reveal that the winner of the 2023 ASVO scholarship for Advanced Wine Assessment Course (AWAC) is Emma Shaw from the Canberra wine region.

Emma is the general manager at Collector Wines and also runs her own business, Pique-Nique, which offers wine appreciation classes and events to encourage consumers to develop their understanding of and comfort with wine, and their appreciation of Canberra wines. Emma also volunteers her time with industry associations across the broader region and is close to completing a Bachelor of Wine Science at Charles Sturt University.

Emma was an outstanding applicant for the scholarship, with her very clear passion for teaching others how to appreciate wine.

The ASVO exists to foster excellence in viticulture and oenology, and a key element of this is to encourage and facilitate education to the highest standard. The AWAC scholarship covers the fees for one ASVO member each year to receive this formal education in wine tasting which will not only further the recipient’s career but also contributes to excellence in the Australian wine industry.

The AWAC was founded in 1992 by the Australian Wine Research Institute. It is an intensive four-day course designed to provide training to potential new wine show judges by developing the sensory analysis capabilities and vocabulary of Australian wine industry personnel at an elite level. The scholarship covers the course fee which in 2023 is $5390.

“I am thrilled,” said Emma when told the news. “I am sure the AWAC course will push my knowledge of wine assessment to new heights. Receiving support by way of a scholarship is greatly appreciated. Thank you to the ASVO board for selecting me amongst the many deserving applicants.”

Stefano Poni, the new editor-in-chief of the Australian Journal of Grape and Wine Research, and Emma Shaw

Maturation recap: Have the options improved?

By Rachel Gore, Director and Principal Consultant, Free Run Consulting

Rachel reviews existing methods for maturing wine — both barrels and alternatives — in light of the current squeeze on capital expenditure and reflects on how quality expectations can be achieved at a cost-effective price.

Given today’s financial pressures that seem to be squeezing us from every direction, is now the right time to reassess our winemaking protocols to see whether we can achieve the same quality parameters but in a different way? We now have access to an array of maturation options that have improved substantially over the last decade so there’s no time like the present to take a closer look.

Wines that have had some influence from oak are, in general, preferred by many wine consumers around the world, however, the practice of barrel maturation is costly due to the price of oak barrels and the extended period of time that the wine must stay in them. To save money and shorten the period of time in contact with wood, the use of cheaper

alternatives, now more than ever, have become more popular.

Wines are normally aged in oak wood barrels for the purpose of improving overall sensory attributes. During the maturation process, wine undergoes many changes due

to the reactions between wine components, the oxygen that slowly diffuses through the oak barrel surfaces and the compounds that are released from the oak itself. Barrels have been used for centuries for preserving and ageing wines, acting as storage vessels that are capable of releasing compounds that affect and improve a wine’s individual characteristics. During the period of maturation in oak, wine undergoes oxidative processes that alter its composition and organoleptic profile due to the transfer of oxygen, phenolic and aromatic compounds from oak to wine. While oxidation usually involves negative implications, the term ‘oxygenation’ suggests the liberation of oxygen and its contact with wine — a technique used in winemaking to improve colour, aroma and texture.

“Ten years ago you could taste the ‘plankiness’ in a wine and could identify that alternatives had been used. These days the sourcing has improved and the focus on the quality of the raw material has really progressed.”

Foldable stillages for wooden barrels

ARMT18/1

Pallet for wooden barrels

A foldable steel pallet with a load capacity of 750 kg. Stacks into a 5-level rack with a height of 5m .

In the ARMT18/1 variant, the barrels rest on rollers. This allows you to conveniently rotate the barrels in order to, for example, wash them inside. Powder coating to any RAL color.

• Capacity: 2 barrels 225Lt or 300Lt

• Weight: 54 kg

• Outside dimensions: 1.8 x 0.8 x 1.0m

• Stacks into a 5-level rack with a height of 5m

• Folding design for optimised transport and intralogistics flexibility.

Quoted and shipped directly from the manufacturer!

In the case of oak barrels, the level of oxygen transferred through the ‘breathing mechanism’ of a barrel depends on the oxygen transfer rate (OTR). In a recent study, it was shown that wines aged in barrels with a high oxygenation rate had a greater ability to consume oxygen, resulting in an increase in colour intensity1. The parameters that will determine the necessary quantity of oxygen include the presence of sulfur dioxide, the initial wine composition (anthocyanins/tannins/ varietal/vineyard and vintage) and the ultimate destiny of the wine. In the case of oak barrels, the OTR will depend on the chosen species, its geographical origin or barrel manufacturing process1. These characteristics will result in a different porosity of wood (coarseness or grain) and also in the degree of oxygen transfer.

Could there be alternate methods of ageing that replicate oxygen diffusion that could be used in conjunction with oak alternatives or additives to produce the same affects?

In this article I will delve deeper into the hidden costs of oak, the use of microoxygenation in conjunction with tannins, oak alternatives and the comeback of the ancient wine vessel amphorae but at what cost?

BARRELS

Barrels have functions beyond serving as a storage vessel. Barrels, in all of their different formats and sizes, allow for the separation of sediment as lees from the wine over a period of time. They provide tannins, allow oxygenation and assist in the stability of colour in red wines. During the ageing process of a barrel, the wood releases compounds into the wine that contribute to an improvement in its organoleptic properties. All of this contributes to the ageing of wine by adding complexity, flavour and longevity, therefore, the wine barrel acts as an active vessel that releases chemical compounds into the wine, improving its physical, chemical and sensory properties.

Depending on its origin, age, thickness of staves, uses, toasting and the time spent in the barrel, the acquired properties are different. As the compounds that can be extracted from oak are finite, factors such as the composition of the wine, maintenance of the barrels and fermentation affect the life of the barrel, decreasing the extraction rate over time. Oak is the most extensively used wood in barrel manufacture due to its hardness, permeability and characteristics. French oak is typically more expensive than American oak due to the

losses involved as a result of its irregular grain and greater porosity. This characteristic means that the wood has to be divided instead of sawn which leads to a lower yield from the wood2

There is a large array of barrel sizes and oak origins now available, with many different formats, for example, barriques, hogsheads, puncheons and oak tanks, all of differing sizes and shapes.

In a small to medium sized winery, each barrel, regardless of the size, is a significant cost and can represent a substantial portion of the winery’s budget. In a larger winery, the individuality of a specific barrel can be lost amongst the sheer volume of oak, therefore, it still represents a substantial expense although the hidden cost of time and labour taken to care for a barrel can often be overlooked.

In order to keep a barrel in a condition fit for winemaking, there is much labour involved. A barrel isn’t something to be bought once — barrels are expensive to buy but they also require constant maintenance that is necessary to maintain their value. The decision on what oak to purchase is sometimes made not on what is the most suitable type of oak for the wine but more with an eye on price. This, along with the lack of understanding around just how much it will cost to maintain a barrel, can sometimes result in a barrel program that is detrimental to the final wine quality which could then jeopardise the long-term viability of the wine’s sale.

The cost of a barrel can be considered an annual expense or a capital investment. Most wineries think of barrels as capital investments meaning that the ‘cost’ of a barrel is not all accounted for at once but is depreciated over a predetermined timeframe.

If a barrel is allowed to dry out, if the hoops are not kept tight or if it isn’t adequately and regularly soused, it becomes worthless. Fill, empty, clean, stack, top, gas, maintain — these operations all add up to a sometimes-hidden cost to the winery.

A barrel will impart oak characteristics for four to five years after which time it starts to become more of a storage vessel. However, there are options to extend the useful life of a barrel using the process of ‘re-shaving’ or ‘refiring’. This is traditionally a labour-intensive process that takes the barrel out of production for some time and requires dismantling the barrel in order to access the inner staves. Another option is the use of a chemically-inert slurry that ‘sands’ the internal surfaces of the oak barrel without the need to pull it apart. The process is suitable for all used red or white barrels up to 12 years old that have been kept in reasonable condition.

OAK ALTERNATIVES

There are definite cost savings when using oak alternatives, but the real savings are in the lack of labour required to maintain an oak storage vessel throughout its lifetime.

As with oak barrels, there seems to be a multitude of options when it comes to oak alternatives — from staves to chips, from beans to liquids — and the products are not only beginning to catch up to barrels in terms of quality, but they are more sustainable and, most importantly, cost effective. The oak alternative industry is constantly coming up with

“In a larger winery, the individuality of a specific barrel can be lost amongst the sheer volume of oak, therefore, it still represents a substantial expense although the hidden cost of time and labour taken to care for a barrel can often be overlooked.”

Photo: Frances Andrijich/Wine Australia

new and innovative ways to closely mimic the impact of barrels. Some of the most recent products include ultra-premium sourcing of oak, new flavours, toasts and blends as well as tools to make the production process quicker, easier and more efficient without sacrificing quality. Ten years ago you could taste the ‘plankiness’ in a wine and could identify that alternatives had been used. These days the sourcing has improved and the focus on the quality of the raw material has really progressed.

Another alternative is the application of oak extracts in a liquid form. These provide winemakers with the ability to make controlled additions and adjustments to complement their wine at any stage of the winemaking process and provide the wine with the benefits of natural oak tannins as well as building the desired flavour profile. Liquid tannins have been very popular, especially during fermentation and at the finishing stages of winemaking. At fermentation, winemakers are replacing solid pieces of oak with liquid products because they are much easier to use. The quality of the finishing tannins gives winemakers the freedom

to make additions in many different forms and for a variety of reasons, whether it is oak, seed or skin tannin that is required to make improvements to the wine.

It should be noted that although phenolic and aromatic compounds present in oak are released during contact between wine and oak alternatives, the oxidative process that occurs in the barrel does not take place in tanks. For this reason, the use of oak alternatives is often combined with micro-oxygenation.

MICRO-OXYGENATION

Micro-oxygenation, or MOX for short, is the controlled addition of oxygen during the winemaking process that attempts to simulate, in a tank, the low uptake of oxygen that occurs in barrels over a long period of time. The technique involves treating a wine with well controlled sub-saturation doses of oxygen over short periods of time and can result in improvements in red wine structure and fruitfulness.

The stage at which micro-oxygenation is started can influence the rate and quantity of oxygen added to wine. It is typically begun at the end of alcoholic fermentation and prior to malolactic fermentation.

An article by Del-Alamo-Sanza and Nevares (2018) indicated that the natural rate of permeation into new French oak barrels is between 1.66mL/L/month and 2.5mL/L/ month. It is important to note that the age of the barrel will affect the oxygen diffusion rate — the older the barrel, the slower the oxygen diffusion rate since most of the wood pores will contain wine sedimentation.

Dose rate and oxygen quantity are the most critical aspects of successful MOX to ensure that wine does not accumulate dissolved oxygen. The stage of wine production at which micro-oxygenation is started can also influence the recorded rate and quantity of added oxygen.

MOX treatment alone does not improve flavours or ellagic tannins that contact with oak can provide. When used in conjunction with either oak alternatives or liquid tannins, however, the results can be highly successful.

It is interesting to note that a New Zealandbased company has entered the market with a new technology for micro-oxygenation users, in conjunction with oak alternatives, that offers wineries portable units that connect to tanks and update automatically every 15 minutes to ensure precise addition rates. The unit uses a different type of diffusion technology that helps get an even dispersion of oxygen throughout the wine volume and better mimics the oxygen exchange in a barrel. It moves around inside the tank rather than simply dropping it in the top, resulting in improved oak integration and stabilisation of colour, decreased astringency and reductive aromas and a more balanced mid-palate structure.

AMPHORAS

An amphora is an ancient Greek or Roman jar or vase made of clay with a large oval body and a narrow cylindrical neck, originally used for transporting and storing grapes, olive oil, grain and other supplies. Because clay is porous, the vessel allows oxygen to penetrate the vessel which helps soften tannins and flavours in the same way that barrel maturation and micro-oxygenation work. Since the clay is a neutral material, the presence of oxygen enables wine to develop without imparting any additional flavours. In addition, clay is an excellent thermal conductor which releases the heat from fermentation so there is normally no need for temperature control. The wine evolves slowly, preserving the primary fresh fruit characters of the wine and giving it a deep rich texture. The presence of oxygen also softens tannins and accelerates tertiary aromas.

Amphoras come in a wide range of sizes and shapes. Most are made with clay but others have been made with sandstone and concrete, however, these are not normally referred to as ‘amphora’.

Due to the nature of these ancient vessels, if cared for correctly they can last for decades, making them financially and environmentally attractive unlike oak barrels that must be replaced every four to five years. The initial outlay, however, is considerable – generally prices begin at around $8000 whereas a stainless-steel tank can be anywhere from $500 for a small variable-capacity tank while an oak barrel can range in price from $1200 up to many thousands of dollars. Concrete tanks that offer benefits similar to amphorae may cost tens of thousands but whilst both concrete and

clay vessels represent a significant investment, those who use them say the benefits are worth the expense.

Before purchasing one, buyers should consider how much oxygen the wine needs, the ease of sanitation of the vessel, the thermal insulation properties and the safety and durability of the vessel. If purchasing from overseas, freight must also be carefully considered as this can be considerable given the weight and shape of the vessel.

None of the information in this article is particularly new or innovative, however, now more than ever, winemaking costs must be scrutinised and the product market must be kept in full and visible site. If quality can be achieved by using alternate methods of ageing and oak integration at a more cost-effective price, why would you not investigate all options!

FOOTNOTES

1Sánchez-Gómez R.; del Alamo-Sanza M.; Martínez-Martínez V. and Nevares I. (2020) Study of the role of oxygen in the evolution of red wine colour under different ageing conditions in barrels and bottles. Food Chem. 328:127040.

2Waterhouse, A.L. and Towey, J.P. (1994) Oak lactone isomer ratio distinguishes between wine fermented in American and French oak barrels. J. Agric. Food Chem. 42:1971-1974.

REFERENCES

Del Alamo-Sanza, M. and Nevares, I. (2018) Oak wine barrel as an active vessel: a critical review of past and current knowledge. Crit. Rev. Food Sci. Nutr. 58:2711-2726.

Boulton, R.B.; Singleton, V.L.; Bisson, L.F. and Kunkee R.E. (1999) Viticulture for Winemakers. In: Principles and Practices of Winemaking. Springer, New York, NY, USA, pp.13-64.

“…if cared for correctly [amphora] can last for decades, making them financially and environmentally attractive unlike oak barrels that must be replaced every four to five years. The initial outlay, however, is considerable…”

Photo: Bouchard Cooperages

Cooperages 1912 adds Maison Moussié to Collection of Premium Wine Barrel Brands

Tanunda (July 20, 2023) – Cooperages 1912 is growing their collection of premium wine barrel brands with the addition of Maison Moussié. Made with a noventique style – which combines innovation and authenticity – Maison Moussié creates luxury barrels positioned for high-end wines. Founded by Thomas Moussié, the company was acquired in September 2022 and will be the fifth premium barrel brand in the Cooperages 1912 collection.

Maison Moussié is best known for their Petra Collection. These barrels are toasted with a unique and patented heated stone toasting technology. The non-combustion process uses natural stones and water elements combined with heat to create barrels that are evenly toasted and consistent. Currently, lava rock and natural jade are being utilized for toasting material.

“Thomas Moussié has a unique approach to innovation, which can be seen in his heated stone toasting technology, that speaks to the innovative approach we’ve taken for decades at Cooperages 1912” said Mark Roberts, General Manager. “Innovation allows us to respond to the present and future needs of customers whose wine styles have continued to evolve. I believe Maison Moussié is an ideal fit with our current collection of wine barrel brands.”

Maison Moussié barrels are crafted in Bordeaux, using a specific wood supply that is seasoned in a dedicated area at the company owned mill in the North-East of France. From the exceptional forests of Tronçais, Bertranges and Bercé to the Centre-France region as well as other famous French forests, Maison Moussié sources the finest forests and tightest grains to craft their high-quality oak barrels.

“In aligning with Cooperages 1912, Maison Moussié will benefit from their exceptional savoir-faire and strong organization to accelerate its growth in Australia,” said Moussié.

Learn more about Maison Moussié from a Cooperages 1912 account manager or by visiting the website www.maisonmoussie.fr.

Cooperages 1912 offers a comprehensive collection of premium wine barrel brands:

Tonnellerie Quintessence, Tonnellerie Tremeaux, Maison Moussié, Heinrich Cooperage and World Cooperage. The Cooperages 1912 team consults directly with winemakers to ensure an optimal pairing between wine and barrel.

Understanding the effect of barrel-tobarrel variation on the colour and phenolic composition of a red wine

By Leonard Pfahl1,2, Sofia Catarino1*, Natacha Fontes3, António Graça3 and Jorge Ricardo-da-Silva1

Barrel-to-barrel

Ageing in oak barrels is a traditional and widespread practice in winemaking worldwide. Alternative containers, such as stainless steel tanks, concrete vessels, or polyethylene tanks, surpass barrels in some respects, like price, hygiene and material homogeneity. Nevertheless, barrels are still firmly established in quality wine production due to their positive influence on the organoleptic quality and complexity of wine1,2.

Various phenomena related to the physical and chemical characteristics of oak are directly responsible for these effects. First, there is water and ethanol non-negligible evaporation due to the porosity of the wood3, as well as some wine absorption by the wood (especially in new barrels).

Second, there is the transfer of extractable compounds, such as ellagitannins and volatile substances, like guaiacol, eugenol, ethyl- and vinyl-phenols, as well as oak lactones (ß-methyl-y-octalactone) and furfural (-derivates)4. The total amount, though, is limited and quickly reduced by the extraction process into wine5. The extracted substances influence sensations, such as astringency and mouthfeel, and increase aroma intensity and complexity.

Third, moderate oxygen permeation and diffusion through the wood promote different reactions of oxidation, polymerisation, copigmentation and condensation, involving anthocyanins and proanthocyanins, which stabilise the colour and reduce astringency. Storage in barrels accelerates the natural sedimentation of unstable colloidal matter, thus contributing to wine stability and limpidity2

Barrels are made from a natural product, wood. The most commonly used species are Quercus petraea (sessiliflora oak), Quercus robur (pedunculated oak) and their hybrids, and Quercus alba (white American oak). Locally, alternative botanical species, other than oak, may also be used6. Wood composition and the production process underlie a variation7

The main influencing factors are the oak species and origin of wood8, the seasoning and its location9, and the toasting process in the cooperage5

Barrels influence wine phenolic composition and colour development during ageing. For this reason, phenolic compounds are likely to be affected by barrel-to-barrel variation. This variation is widely known to winemakers, resulting in tastings and analytical control of individual barrels. Despite these facts, there is little to be found in the literature regarding barrel-to-barrel variation.

Variation of barrel influence can be problematic for analyses of barrel lots as it bears the potential of misinterpretation of results. This study aimed to shed light on the variable influence of barrels on wine colour, pigments and phenolic composition of woodaged wine. This trial stands out due to its practical background with a wine produced at winery scale. The large number of 49 barrel samples from four cooperages resulted in robust results (Figure 1).

EFFECT OF COOPERAGE ON BARREL-TOBARREL VARIATION

The Principal Component Analysis (Figure 2, see page 20) revealed overlapping areas

for all cooperages. It’s therefore consistent that no significant differences were found between the cooperages A, C and D for almost all analysed parameters.

However, for some analytical parameters cooperage B revealed significant differences between just one or two of the other cooperages but also, in a few cases, to all other cooperages1. Why cooperage B showed slightly different characteristics might originate in a smaller oxygen uptake through the wood and rifts between the staves9. Hence, this might be related to the cooperage’s production techniques and oak wood selection. To conclude, the wine aged for 12 months in different barrels varied in its phenolic and chromatic characteristics, but the cooperage of an individual barrel could not explain these variations.

Furthermore, it was checked if the cooperage had an influence on the barrelto-barrel variation by comparing the average coefficient of variation to the barrel-to-barrel variation of each cooperage.

The standard deviation ranged from 0.5 percent for general physical-chemical parameters, over 1.2% for most phenolic parameters, to 3.1% for pigments and 7.9% for anthocyanin-related parameters1. Due to the small standard deviations, it can be concluded that the cooperages do not differentiate from each other with practical relevance in their internal variation for most parameters analysed in this trial, with the exception of pigments and especially anthocyanin-related parameters.

1Linking Landscape, Environment, Agriculture and Food Research Centre, Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal 2DLR – Dienstleistungszentrum Ländlicher Raum Rheinpfalz, Neustadt an der Weinstraße, Germany 3Sogrape Vinhos S.A., Portugal *Corresponding author: sofiacatarino@isa.ulisboa.pt

variation is familiar to winemakers, yet there is little in the literature regarding the phenomenon. Portuguese researchers set out to shed light on the influence of this variation on wine colour, pigments and the phenolic composition of a red wine produced at industrial scale from the grape variety Touriga Franca which was used to fill 49 new French oak barrels from four different cooperages with medium toasting levels.

HARVEST of Touriga Franca (Vitis vinifera L.), PDO Douro, Portugal, 2017 vintage

2 CONVENTIONAL RED WINEMAKING at industrial scale (28°C alcoholic fermentation; spontaneous malolactic fermentation)

3 BARREL FILLING

49 new barrels, 4 cooperages (Quercus petraea), medium toasting

4 12 MONTHS OF AGEING

T.: 15-18°C Humidity 75-85% S02 corrections were carried out periodically in order to keep a free S02 level of 40 mg/L, combined with topping up the barrels with wine of the same batch stored in a stainless steel tank.

5 SAMPLING

51 samples

6 CHEMICAL ANALYSIS

• General physical and chemical analysis (FTIR)

• Chromatic characteristics (CIELab parameters: H*, L *, C*, a* and b*)

• Anthocyanin-related parameters

• Total phenols

• Flavonoids and non-flavonoids phenols

• Tanning power

• Copigmentation

• Flavanol monomers, oligomeric proanthocyanidins and polymeric proanthocyanidins

STATISTICAL ANALYSIS

Principal components analysis (PCA), Variance analysis (ANOVA)

Investigates the relationships between barrels and assesses cooperage and individual barrel effect.

Coefficient of variation (CV )

Shows the degree of variability in relation to the population average. Identifies the variation from barrel to barrel and between the cooperages.

Required barrel samples

Can be seen as a translation of the observed variation of a parameter into a number of samples of a barrel lot needed to retain results of a certain reliability.

Figure 1. Schematic representation of the ageing assay1 .

EFFECT OF BARREL ON BARREL-TOBARREL VARIATION

Chemical characteristics analysed in this experiment showed individual barrel-tobarrel variation with a range from 0.01% to 37.2%. General physical-chemical parameters showed the lowest barrel-to-barrel variation in the trial (always less than 2%).

Exceptions were volatile acidity and residual sugar; however, this variation is likely to originate in different microbiological activity and is not necessarily linked to the influence of the barrel. It can be concluded that the effect of barrel ageing on general characteristics, like density, alcoholic strength or total dry matter, is either small or similar, with less than the individual barrels2

The same is true for chromatic characteristics to a certain degree. On the other hand, the change from blue to yellow notes was prone to a higher variation, which is likely related to the variation found for anthocyanins. The observed variation for total pigments and polymerisation index led to the conclusion that polymerisation reactions are probably influenced by the barrel, most likely by a variance in the permeation of oxygen.

In summary, these findings indicate that the effect of barrel-to-barrel variation on the chemical parameters of a red wine depends on each specific parameter and is not uniform. In particular, anthocyanin content shows high variation between barrels in general and is, to a lesser degree, impacted by a cooperage1

BARREL SAMPLE REQUIREMENTS

Upon analysing a barrel lot filled with the same initial wine, one can ask, “How many barrels need to be analysed to get reliable results representative of all the wine in the different barrels if hypothetically racked and joined together in a big tank?”

The characteristics of this hypothetically racked wine from all the barrels is referred to as the “true barrel lot mean”.

Reliable results are a point of discussion as not every situation requires the same exactness of results. More analyses usually translate to increased accuracy but require more resources too. Therefore, for practical reasons, a compromise is often necessary. To be able to make this decision, it is beneficial to know the link between the analytical parameter in focus, the necessary number of barrel samples and the resulting accuracy of results.

The analytical parameter to be analysed plays a critical role as variation from barrel-to-barrel changes with different parameters, and the greater the variation, the more samples of a batch are needed to determine, in their average, the true barrel lot mean.

To investigate this link, a backwards calculation based on the high number of samples of this trial was conducted. The calculation requires a predefined desired precision for the results, which has been set at 2%, 5%, 10%, 15% and 20%1. For better understanding, a precision of 10%, for example, means all results will be inside a range of 5% above and 5% below the true barrel lot mean.

The results revealed that all phenolic and chromatic characteristics, except for the tannin fractions analysis and anthocyaninrelated parameters, can be analysed with only two barrel samples per barrel lot at 20% accuracy. When increasing the exactness, more analytical parameters require larger sample numbers per barrel lot. At a 10-percent range around the true barrel lot mean, several analytical parameters require more than two barrels per lot, for example, total pigments and polymerisation index. At a 5% range around the true barrel lot mean, only clarity, tonality and

colour due to copigmentation, as well as most physical-chemical parameters, can be analysed with up to two barrels per lot.

General physical-chemical parameters required the smallest samples due to low barrel-to-barrel variation. To achieve reliable results (5% around the true barrel lot mean) for the analysis of general wine characteristics and wine colour, in most cases between one to three barrels per barrel lot are sufficient. Analytical parameters influenced by wine maturation, such as the formation of polymeric pigments, polymerisation of phenolics and especially anthocyanin-related parameters, require more samples per barrel lot; otherwise, a reduction in the accuracy of the results needs to be accepted.

LIMITS OF THE STUDY

This experiment included only new barrels with the same toasting level while for barrel lots of different age and toasting levels, a qualified statement cannot be made. The number of barrel samples needed to analyse volatile acidity and residual sugar in a barrel lot should be calculated with care because these parameters are influenced not only by the barrel but by many other factors.

Figure 2. Principal Component Analysis performed on wines aged in oak barrels from the cooperages A, B, C and D and bottle-matured wine in a total of 50 wines. The wines are represented in the plane of the two first components which express, respectively, 49 percent and 18 percent of the total variation.

Therefore, in practice, analyses of these two parameters might need different barrel sample amounts.

CHEMICAL PARAMETERS DIFFER IN THEIR VARIATION

It could be shown that the influence of an individual barrel on barrel-to-barrel variation on wine phenolics and pigments was greater than the influence of the manufacturing cooperage. The chemical parameters analysed in this study were prone to barrel-to-barrel variation at individual levels, overall ranging from almost 0% up to 37%. Parameters related to anthocyanins in particular were found to have a high barrelto-barrel variation.

Barrel-to-barrel variation of a chemical parameter influences the required sample size needed per analysed batch. Detailed recommendations on the required sample size for certain chemical parameters at different levels of accuracy were calculated

and can be used as an aid to generate measurements involving barrel lots.

REFERENCES

1Pfahl, L.; Catarino, S.; Fontes, N.; Graça, A. and Ricardo-Da-Silva, J. (2021) Effect of barrel-to-barrel variation on colour and phenolic composition of a red wine. Foods 10(7):1669, https://doi.org/10.3390/ foods10071669

2Waterhouse, A.L.; Sacks, G.L. and Jeffery, D.W. (2016) Understanding Wine Chemistry; 1st ed.

3Ruiz De Adana, M.; López, L.M.; Sala, J.M. and Fickian, A. (2005) A Fickian model for calculating wine losses from oak casks depending on conditions in ageing facilities. Appl. Therm. Eng. 25:709-718, https://doi.org/10.1016/j.applthermaleng.2004.07.021

4Towey, J.P. and Waterhouse, A.L. (1996) Barrelto-barrel variation of volatile oak extractives in barrelfermented Chardonnay, Am. J. Enol. Vitic. 47:17-20, doi: 10.5344/ajev.1996.47.1.17

5Chira, K. and Teissedre, P.L. (2013) Relation between volatile composition, ellagitannin content and sensory perception of oak wood chips representing different toasting processes. European Food Research & Technology 236:735-746, doi:10.1007/ s00217-013-1930-0.

Cooperages 1912 names Mark Roberts as new General Manager

Tanunda (June 20, 2023) – Cooperages 1912 announces the appointment of Mark Roberts as general manager, starting from July 1, 2023. He will be taking over management responsibilities for Patrick Schwerdt who served as a General Manager from 1997 to 2023. Patrick will now be selling spirit barrels.

With over 21 years’ of experience working for Cooperages 1912, Mark Roberts was an account manager for Oak Solutions Group, a sister company offering innovative oak products and tannins to winemakers and distillers. With his new position, Mark will be leading both wine barrels and oak products sales management activities in Australia. As General Manager of Cooperages 1912, he will also be responsible for overseeing all aspects of operational functions of the company, including the local production of Heinrich Cooperage barrels. Leading a team dedicated to elevate experiences, Mark Roberts and the Cooperages 1912 employees will work together to deliver high-quality products and services to the winemakers.

Commenting on his promotion, Mark Roberts said: “I am excited to be leading our Australasian team into the future. In this day and age, you need to rapidly evolve, be dynamic and adaptive to succeed. I feel that Cooperages 1912 has been on this trajectory of evolution to be ahead of the curve.”

“We are very pleased to have Mark Roberts and Patrick Schwerdt moving to these new positions and have them representing Independent Stave Company on both the wine and spirit sides,” said Franck Renaudin, Director of Artisan Cooperages and International Sales. “This will benefit both our company and customers, as the need for high-quality oak barrels and other cooperage products continues to grow”.

Before embarking on his career with Cooperages 1912, Mark completed vintages in Australia and overseas before graduating from Adelaide University studying Wine Marketing. Currently, Mark is studying an MBA at Adelaide University.

Cooperages 1912, a subsidiary of Independent Stave Company, offers a comprehensive collection

6Organisation Internationale de la Vigne et du Vin (OIV) International Code of Oenological Practices; Organisation Internationale de la Vigne et du Vin (OIV): Paris, France, 2017; ISBN 9791091799737.

7Mosedale, J.R.; Puech, J.L. and Feuillat, F. (1999) The influence on wine flavour of the oak species and natural variation of heartwood components. Am. J. Enol & Vitic. 50:503-512.

8Miller, D.P.; Howell, G.S.; Michealis, C.S. and Dickmann, D.I. (1992) The content of phenolic acid and aldehyde flavour components of white oak as affected by site and species. Am. J. Enol. & Vitic. 43:333-338.

9Martínez, J.; Cadahía, E. and Fernández De Simón, B.; Ojeda, S. and Rubio, P. (2008) Effect of the seasoning method on the chemical composition of oak heartwood to cooperage. J. Agric. Food Chem. 56:3089-3096, doi:10.1021/jf0728698.

This article was originally published in the May 2023 issue of the US-based Wine Business Monthly and is a summary of a much larger peer-reviewed article published in the scientific journal Foods, https://doi.org/10.3390/ foods10071669. WVJ

of premium wine barrel brands: Tonnellerie Quintessence, Tonnellerie Tremeaux, Maison Moussié, Heinrich Cooperage and World Cooperage. Cooperages 1912 also offers innovative oak products and tannins with sister company Oak Solutions Group as well as ISC spirit barrels.

Cooperages 1912

59 Basedow Rd, Tanunda SA 5352 +61 8 8563 1356

cooperages1912.com.au

Consumer response to wine made from smoke-affected grapes

By Eleanor Bilogrevic, WenWen Jiang, Julie Culbert, Leigh Francis, Markus Herderich and Mango Parker, The Australian Wine Research Institute, Urrbrae South Australia 5064

Consumer studies using three different sets of smoke-affected wines have delivered a clearer picture of the consumer acceptance of smoke characters in wine. The data will help producers make informed decisions about how best to manage smoke-affected wines, taking into account likely consumer responses.

IN BRIEF

INTRODUCTION

The increasing frequency of wildfires and total area burned globally has been linked to climate change as the main driver (Canadell et al. 2021, Richardson et al. 2022). Wine produced from grapes in vineyards exposed to smoke from nearby grass or forest fires can exhibit strong smoky aromas and flavours due to orthonasal and retronasal smoky odours (Parker et al. 2012). Commonly referred to as ‘smoke taint’, these characters are considered highly undesirable by winemakers. The losses to the Australian wine sector due to smoke from wildfires and prescribed burns have been estimated at $1.4 billion AUD since 2003 (Krstic et al. 2021).

The issue is also a challenge for the global wine industry and has caused significant quality defects and economic impacts in recent years throughout Europe, California and South America (Mirabelli-Montan et al. 2021).

There are a broad range of descriptors attributed to smoke taint in wine, such as smoky, medicinal, campfire ash, plastic and burnt aromas; and ash tray, drying and bitter and a lingering ashy aftertaste on palate (Krstic et al. 2015, Parker et al. 2012, Ristic et al 2011). Some smoky flavour can also be found in wines that have not been exposed to smoke, due to other processing and maturation steps, notably the use of oak barrels that have been toasted or charred using a flame (Francis and Williamson 2015, Koussissi et al. 2009, Prida and Chatonnet 2010). Toasted oak can impart volatile phenols to a wine, particularly guaiacol,

4-methylguaiacol and syringol (Chatonnet et al 1999), which are produced during oak toasting from the same lignin degradation process that occurs when wood smoke is generated (Pollnitz et al. 2004, Spillman et al. 2004). Other common wine flavours that can be present in non-smoke-affected wines and can be confused with smoke taint have been described as medicinal, burnt rubber and leather, which are generally considered negative attributes (Lattey et al. 2010, Wedral et al. 2010).

The chemical basis for the smoky characters in wildfire smoke-affected wines is complex, with a large number of compounds implicated. The compounds most associated with smoke-affected wines are volatile phenols (originating from smoke) and phenolic glycosides (produced in grapes by the addition of sugar units to the volatile phenols).

These volatile phenols impart smoky aroma and flavour, and include guaiacol, 4-methylguaiacol, o-cresol, m-cresol, p-cresol, syringol and 4-methylsyringol (Parker et al 2012).

A large number of phenolic glycosides have been identified in smoke-exposed wines (Caffrey et al. 2019, Hayasaka et al. 2010), and routine markers for smoke exposure of grapes include syringol gentiobioside (SyGG), methylsyringol gentiobioside (MSyGG), phenol rutinoside (PhRG), guaiacol rutinoside (GuRG), cresol rutinosides (rutinosides of o-cresol, m-cresol and p-cresol) (CrRG), and methylguaiacol rutinoside (MGuRG) (Hayasaka et al. 2013). Beyond their role as biomarkers

■ Three studies assessing sets of Pinot Noir rosé, Chardonnay and unoaked Shiraz wines with varied smoke flavour were conducted to investigate whether consumers respond negatively to smoky attributes.

■ Detailed data analysis revealed wine consumers fell into three categories: highly responsive to smoke, moderately responsive, and a smaller group of non-responders.

■ Overall, wines rated high in smoke flavour were less liked compared to non-smoke-affected wines.

■ Independent of wine type, there was a strong negative correlation between smoky flavour and overall consumer liking.

■ This information can guide assessments of risk from smoke exposure of grapes and potential for quality defects in wine, as well as identify and benchmark management options for wine producers.

indicating smoke exposure, the phenolic glycosides can also contribute to the flavour and lingering aftertaste of smoke-affected wines, by releasing odorants in-mouth during consumption or during extended periods of storage (Mayr et al. 2014, Parker et al. 2020). While the concentrations of volatile phenols and phenolic glycosides are regularly compared to concentrations found in nonsmoke exposed wines to determine whether

there is evidence of smoke exposure (Coulter et al. 2022), the exact relationship between chemical composition and concentration, and the intensity of smoky flavours in wine is complex (Parker et al. 2023). Highly smokeaffected grapes can result in wines with strong smoky flavours and high concentrations of volatile phenols and/or glycosides.

For wine made from mildly smoke-affected grapes, smoky flavours are not always evident. A recent study based on over 60 unique smoke-affected Chardonnay, Pinot Noir and Shiraz wines found that statistical models based on guaiacol, o-cresol, m-cresol, p-cresol, and some glycosides gave good predictions of smoke flavour intensity, with a slightly different optimal model for each cultivar (Parker et al. 2023). In the absence of robust chemical models for predicting smoky flavours in other cultivars and wine styles, sensory analysis remains a critical tool to determine whether a wine has quality defects or is acceptable.

To inform critical business decisions it is imperative that sensory assessment is carefully conducted using recognised protocols (Lawless and Heymann 2010). However, sensory evaluation of potentially smoky wines is challenging: the response of individuals to smoke volatile compounds such as guaiacol is known to be variable due to genotypic and phenotypic differences among individuals (Mainland et al. 2014). Previous work has shown a large degree of inter-individual variation in sensitivity to guaiacol and also guaiacol glucoside (Parker et al. 2020). Many individuals perceive a long-lasting smoky sensation from guaiacol glucoside when the glucoside is hydrolysed in the mouth and the volatile odorant is released which is perceived retronasally (Parker et al. 2012, Mayr et al 2014).

The variation in response to phenolic glycosides was found to be related to volatile odour sensitivity rather than the ability to cleave volatile odorants from the precursors (Parker et al. 2020). Therefore, individuals who are sensitive to these volatile phenols and glycosides experience a lengthy smoky aftertaste and, as a consequence, carryover effects are a concern in smoke sensory assessments (Fryer et al. 2021).

Very little is known about the levels of smoke aroma and flavour that are acceptable to consumers. For some off-flavours, such as cork taint (Prescott et al. 2005), consumer preference data has found that the presence

of any degree of perceptible taint can be considered unacceptable.

For other wine flavours where consumers respond negatively, such as oxidation, ‘Brett’, or sulfur characters, a low intensity as determined by a trained sensory panel can potentially have no effect on consumer acceptance (Francis and Williamson 2015). A previous study assessing consumers’ acceptance of guaiacol added to a Merlot wine found an addition of 25μg/L lowered liking scores (although not significantly) compared to the score for the base wine, but 50μg/L added resulted in a significantly lower liking response (Herderich et al. 2012).

In addition, cluster analysis indicated a relatively small group of consumers (30%) responded negatively to the 25g/L addition. The sensory characters in wildfire smokeaffected wines are likely more complex, with other compounds involved and the potential for matrix effects (Parker et al. 2012), and there is no research to our knowledge that has assessed the acceptance of smoke-affected wines by wine consumers.

For determining whether a wine may be unacceptable due to grapevine exposure to smoke from nearby fires, consumer liking data are required to complement the interpretation of trained sensory panel measures. If acceptability limits can be established with the help of consumer responses (Manzocco 2016), trained panel results or potentially chemical analytical data can be used for better informed decisionmaking in the wine industry.

This study aimed to test whether consumers respond negatively to wines made from smoke-affected grapes and, if so, to provide guidance regarding the level of wildfire smoke flavour that might be acceptable. As numerous volatile and non-volatile compounds can contribute to smoky flavour, sets of smoke-affected wines were used rather than chemical additions to a base wine. The first study involved red wines made under controlled conditions from grapes sourced from vineyards with varied degrees of wildfire smoke exposure.

This experiment was complemented by studies with two heavily smoke-affected wines, a rosé and a white wine, blended with different proportions of an unaffected wine.

A secondary aim of this research was to assess the applicability of a streamlined smokespecific panel rating procedure in comparison to a full quantitative descriptive analysis (QDA) approach.

MATERIALS AND METHODS Wines

Shiraz

Eight Adelaide Hills (South Australia) Shiraz wines from vintage 2020 were selected from a study investigating the chemical composition of wine after a single early-season smoke event (Jiang et al. 2022). Each of the wines were made in an identical fashion from vineyards with a different degree of smoke exposure during the grape ripening season, which resulted in a range of volatile phenol and phenolic glycoside concentrations as well as some variation in basic composition. The wines had a range of smoke flavour ratings, including control wines with low smoke flavour ratings produced from grapes with no known smoke exposure (SHZ A and SHZ B). Full details of the grape and wine composition and sensory ratings can be found in the referenced manuscript (Jiang et al. 2022).

Following trained panel sensory assessments, a subset of wines was selected for the consumer liking study.

Pinot Noir rosé

Pinot Noir grapes on the vine before harvest were exposed to wildfire smoke from the Huon Valley, Tasmania, forest fire in January 2019 and were selected and processed into a rosé style juice in Tasmania then transferred to WIC winemaking services at the Hickinbotham Roseworthy Wine Science Laboratory in Adelaide, South Australia. Grape selection, processing and composition results are described in Culbert et al. (2021).

Free run Pinot Noir juice was made into rosé style wine using standard small-scale winemaking protocol. Wine was bottled into 375mL bottles and stored at 15°C for three months before sensory analysis.

A similar style commercial rosé wine from a region where no wildfires were present, sourced from the same vintage (bottled 2019 Pinot Noir rosé, Adelaide Hills, South Australia) was selected after a preliminary sensory assessment of several candidate Pinot Noir rosé wines, together with consideration of basic chemical composition as well as the concentration of smoke and oak-derived compounds.

The smoke-affected Pinot Noir rosé was blended by volume with the non-smokeaffected rosé to make wines with different degrees of smoke aroma and flavour intensities as follows: 0% smoke-affected wine (PNR 0%); 6.25% smoke-affected wine with

93.75% unaffected wine (PNR 6.25%), 12.5% smoke-affected wine with 87.5% unaffected wine (PNR 12.5%), 25% smoke-affected wine with 75% unaffected wine (PNR 25%), 50% smoke-affected wine with 50% unaffected wine (PNR 50%) and 100% smoke-affected wine (PNR 100%). After the trained panel assessment, a subset of the blends were prepared for the consumer liking test (PNR 0%, PNR 6.25%, PNR 12.5%, PNR 25%, PNR 100%). New bottles of both smokeaffected and non-smoke affected were freshly opened for each day of the assessments, and fresh blends prepared immediately prior to assessment.

Chardonnay

A 2020 smoke-affected Chardonnay wine was made from grapes from North-East Victoria which had been exposed to smoke from fires while ripening on the vine before harvest during the 2019-20 season. Grapes were frozen in Victoria to follow the biosecurity requirements and transferred to the WIC winery for the winemaking process. The winemaking followed the same protocol as for the Pinot Noir rosé.

For this study, the smoke-affected Chardonnay wine had an alcohol content of 15.2%v/v, which is high compared to typical table wines. A non smoke-affected Chardonnay of a similar style was sourced from the same vintage (2020 Chardonnay, Barossa Valley) after a preliminary sensory assessment of several candidate Chardonnay wines. The non-smoke-affected wine was selected with consideration of basic chemical composition as well as the concentration of smoke and oak related compounds, but for this study the wine selected had a lower alcohol concentration which was adjusted prior to presenting to the consumers as detailed below.

The blends were prepared to make wines with different degrees of smoke aroma and flavour intensities as follows: 0% smokeaffected wine (CHA 0%), 6.25% smoke-affected wine with 93.75% unaffected wine (CHA 6.25%), 12.5% smoke-affected wine with 87.5% unaffected wine (CHA 12.5%), 25% smoke-affected wine with 75% unaffected wine (CHA 25%), 50% smoke-affected wine with 50% unaffected wine (CHA50 %) and 100% smoke-affected wine (CHA 100%). Similar

to the Pinot Noir rosé, after the trained panel assessment, a subset of five samples was prepared for the consumer liking test (CHA 0%, CHA 12.5%, CHA 25%, CHA 50%, and CHA 100%). On the day of the consumer test, 18mL of food grade ethanol (Tarac Neutral grape spirit, ≥96%v/v) was added to each bottle (750mL) of the non-smoke-affected Chardonnay to achieve a similar final alcohol concentration, between 15.2% and 15.5%v/v for all treatments.

Trained panel assessments

Screening, selection and training

A large pool of screened, qualified and experienced assessors with previous experience in wine smoke sensory evaluation (n>30) were additionally screened for their sensitivity to assess specific smoke compounds. The assessors, who were all AWRI staff members, were screened for their ability to perceive smoke flavour from phenolic glycosides (guaiacol glucoside and m-cresol glucoside) dissolved in MilliQ water, and correctly identified guaiacol glucoside and m-cresol glucoside at concentrations of

0.5g/L by duplicate 3-alternative forced choice difference testing (3-AFC). For these difference tests, two-minute breaks were imposed between each sample. All selected assessors correctly identified the glycoside sample in at least 75% of the tests and provided comments indicating smoke related flavours.

Prior to formal sensory assessments, all panellists were extensively trained for smoke aroma and flavour in wine.

A process of familiarisation of smoke aroma and flavour across different varieties was used during training. Examples of real smoke-affected wines, as well as mixtures of volatile compounds and reference standards were presented to the panel. From this, the panel came to a consensus for the definition of smoke aroma and flavour. Examples of other possible faults and taints in wines were also presented to provide context and clarity

to smoke characters and avoid confusion with other off-flavour compounds. All panellists also completed an informal smoke evaluation (as described below) under the same conditions that they would experience during formal evaluations, but the results and feedback were discussed immediately after the evaluations. Panellists were told which were the clean controls and which were smoke-affected samples, and then discussed any confusable attributes. The panellists were given individual performance feedback regarding their repeatability (standard deviation), agreement with the rest of the panel (distance from the panel mean) and ability to discriminate between the wines (one way ANOVA). These performance measures were calculated and given to panellists after every smoke study for ongoing evaluation, motivation and skill development.

From this ‘smoke sensitive’ group, smaller panels were convened to evaluate each of the wines sets using a consistent cohort where possible, but with some changes between the panels due to the availability of the panellists. The assessors (10 for the Shiraz set, 11 for the Pinot Noir rosé set, eight for the Chardonnay and 12 for the Shiraz descriptive analysis) were then selected based on availability and performance on smoke attributes.

Quantitative Descriptive Analysis of Shiraz wines

A panel of 12 assessors (10 females, two males, average age of 53 years (SD = 8.2)) was convened to assess the Shiraz wines. All panellists were part of the Australian Wine Research Institute (AWRI) trained descriptive analysis panel with previous experience in wine sensory descriptive analysis (minimum

Aroma

Dark Fruit A Intensity of the aroma of blackberries, blueberries and dark cherries

Blackcurrant A Intensity of the aroma of blackcurrant and Ribena

Red Fruit A Intensity of the aroma of strawberry and raspberry

Eucalypt A Intensity of the aroma of eucalyptus leaves

Smoke A Intensity of the aroma of smoke, burnt ash, smoked meats and Band- Aids.

Earthy A Intensity of the aroma of dust and dry earth

Spices A Intensity of the aroma of pepper and sweet spices: cinnamon, nutmeg and cloves

Jammy A Intensity of the aroma of jam and cooked/dried fruits

Vinegar A Intensity of the aroma of vinegar and pickled vegetables

4 whole blueberries (Welch’s) and 3 whole blackberries (Welch’s)

5 mL Blackcurrant syrup (Ribena) in 30 mL water

2 whole strawberries (Welch’s)

20 μL 1,8-cineole at 1 g/L

70 μL Guaiacol at 605.3 mg/L, 20 μL o-cresol at 519 mg/L, 35 μL m-cresol at 238 mg/L and 21 μL p-cresol at 505 mg/L

10 g soil

2 whole cloves (Masterfood’s), < 0.01 g ground black pepper (Saxa) and < 0.01 g ground cinnamon (Masterfood’s)

10 g blackberry jam (Beerenberg) and 5 g satsuma plum jam (Beerenberg) in 50 mL water – not in wine

5 mL pickle juice/brine (Fehlbergs) and 2 mL white vinegar (Black & Gold)

Eggy/Drain A Intensity of the aroma of rotten eggs and dirty drains Std 1. 1 scrambled egg Std 2. 40 μL 2-mercaptoethanol at 2 % and a pinch of wood ash

Pungency Intensity of the aroma and effect of alcohol

Palate

Overall Fruit F Intensity of the overall fruit flavours

Earthy F Intensity of the flavour of dust and dry earth

4 mL of 95 % food grade ethanol (Tarac Technologies)

Smoke F Intensity of the flavour of smoke, burnt ash, smoked meats and Band-Aids.

Acidity Intensity of acid taste in the mouth including aftertaste

Astringency The drying and mouth-puckering sensation in the mouth. Low = coating teeth; Medium = mouth coating & drying; High = puckering, lasting astringency

Hotness The intensity of alcohol hotness perceived in the mouth, after expectoration and the associated burning sensation. Low = warm; High = hot, burning

Bitterness The intensity of bitter taste perceived in the mouth, or after expectoration

Viscosity The perception of the body, weight or thickness of the wine in the mouth. Low = watery, thin mouth feel. High = oily, thick mouth feel

1 g/L L-(+)-tartaric acid (Chem-Supply) in water

0.5 g/L aluminium sulfate (Ajax fine Chem Supply Pty Ltd in water

10% food grade alcohol (Tarac Technologies) in water

0.15 g/L quinine sulfate (Sigma Aldrich) in water

1.5 g/L carboxymethylcellulose sodium salt (Sigma Aldrich) in water

All wine standards were added to 100 mL of 2019 Winesmiths premium bag-in-box Shiraz (2L) unless otherwise noted. Aroma standards were sniffed, and palate standards were tasted.

Table 1. Shiraz QDA wine sensory attributes, definitions and composition of reference standards.

40 hours) in addition to their ability to perceive the phenolic glycosides mentioned above.

Generic descriptive analysis (Heymann et al. 2016) was used. Assessors attended three two-hour training sessions to determine appropriate descriptors for the set of wines.

All the wines from the study were progressively used during training sessions to generate and refine appropriate descriptive attributes and definitions through a consensus-based approach. In the second session, standards for aroma, taste and mouthfeel attributes were presented and discussed and these standards were also available during the subsequent training sessions, the booth practice session and the formal assessment sessions. As a warmup exercise, assessors revisited these aroma and palate standards at the beginning of each formal assessment session.

Following the third training session, assessors participated in a practice session in the sensory booths under the same conditions as those for the formal sessions. After the practice session, any terms that needed adjustment were discussed and the final list consisted of 23 attributes. (Table 1).

Samples were presented to panellists in 30mL aliquots in three-digitcoded, covered, ISO standard wine glasses at 22-24°C in isolated booths under daylight fluorescent lighting.

Randomised presentation order was followed except in the practice sessions when there was a constant presentation order. All samples were expectorated. In the practice booth sessions, the assessors were presented with 12 wines across four trays, with three wines per tray. In the formal evaluation sessions, the eight Shiraz wines were presented to assessors in triplicate in an incomplete Williams Latin Square random block design. In total, the assessors were presented with 24 wines, split across two days, with four trays of three wines presented on both days of formal sensory assessment.

The assessors were required to wait for one-minute before they could finalise the palate ratings for their assessments, to account for any lingering attributes and aftertastes. There was a forced two-minute rest between samples and filtered water was used for rinsing between samples. A minimum 10-minute rest was required between sets of three samples, during which the assessors left the booths. A new bottle was used for each of the presentation replicates.

The intensity of each attribute (listed in Table 1) was rated using an unstructured 15cm line scale (0 to 10), with indented anchor points of ‘low’ and ‘high’ placed at 10% and 90%, respectively. All sensory data was collected by Compusense20 sensory evaluation software (Compusense Inc., Guelph, Canada).

Smoke Rating Panel (SRP) Assessment

The assessors rated smoke aroma (orthonasal assessment defined as any type of smoke aroma, including hickory smoke or artificial smoke, phenolic, burnt aroma associated with ashes, ashtray, fire ash, including also medicinal, band aid), smoke flavour (in-mouth assessment defined as including bacon, smoked meat and ashy aftertaste), overall fruit aroma (orthonasal assessment defined as including red fruit, red berry, strawberry, raspberry and cherry for the Pinot Noir rosé and Shiraz, and defined as any type of citrus fruit, stone fruit, and tropical fruits including pineapple for the Chardonnay) and overall fruit flavour (inmouth assessment) for each of the three wine sets. A term of ‘other’ was available for both aroma and flavour to capture any additional noteworthy characteristics in the wines. The intensity of each attribute was rated

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using an unstructured 15cm line scale (0 to 10), with indented anchor points of ‘low’ and ‘high’ placed at 10% and 90%, respectively.

All wines were presented in duplicate, 30mL aliquots, in three-digit-coded, covered, ISO XL5 standard wine glasses at 22-24°C in isolated booths under colour-masking lighting, with randomised presentation order in a modified Williams Latin Square design generated by Compusense20 sensory evaluation software (Compusense Inc., Guelph, Canada).

A minimum 30-second delay was enforced before assessors could finalise the palate ratings for their assessments to account for any lingering attributes and aftertastes and then a two-minute break was enforced between each wine do reduce carryover effects. Assessors were encouraged to rinse with water.

Consumer hedonic assessments

Following the trained panel evaluations, a subset of wines was selected for assessment by regular wine consumers.

For each set, consumers (aged 18-65) were recruited using the selection criteria as detailed below and were not linked to any

marketing or wine industry organisation. All testing was conducted in isolated sensory booths with spittoons and water provided, where consumers rated each wine within each respective study for overall liking on the nine-point hedonic scale from ‘like extremely’ to ‘dislike extremely’ (Peryam and Pilgrim, 1957). For each assessment, expectoration and rinsing with water between wines was encouraged. All wines were assessed under daylight-type lighting. Prior to each test, consumers were asked to complete an entrance questionnaire to obtain demographic information and, on completion, an exit survey exploring spending behaviour and attitudes to food and wine occasions.

All consumers were required to provide informed consent prior to commencing the study and were reminded that their participation was voluntary, and they could withdraw from the study at any point. All consumers were compensated for their time with a gift voucher at the completion of each appointment. All wines were presented with balanced randomised presentation order as provided by Compusense20 (Compusense Inc., Guelph, Canada).

Shiraz

Consumers (n = 111, 54% females, 18-60 years old) were recruited from the consumer database of the Australian Wine Research Institute and selected if they consumed ‘red wine at least once per fortnight’. Testing was undertaken between 20-27 September 2021, in Adelaide, South Australia, with samples presented at 22-24°C in 25mL aliquots in three-digitcoded ISO standard wine glasses. Participants were required to take a five-minute rest between each wine.

Pinot Noir rosé

A central location test was conducted with 82 consumers (31 males, 51 females, 18-65 years old) recruited from the consumer database of the Australian Wine Research Institute on the basis of ‘drinking rosé wine at least one to two times per year’. Testing took place between 16-19 December 2019 in Adelaide, South Australia. Wines were presented in black wine glasses (30mL) at room temperature (22-24°C) with a minimum two-minute break between samples.

Chardonnay

White wine consumers (n = 124, 52% female, 18-65 years old) from Melbourne,

Victoria, were selected on the basis of ‘drinking white wine at least once per week’, recruited from a database of a professional recruitment company. All participants attended sessions at private research facilities between 29 June and 1 July 2021. Samples were presented chilled (37°C) in 25mL aliquots. Participants were required to take a five-minute rest between wines.

Data Analysis

The trained panel performance was assessed using Compusense20 software and R with the SensomineR (sensominer.free.fr/) and FactomineR (factominer.free.fr/) packages. The performance assessment included analysis of variance for the effect of assessor, wine and presentation replicate and their two-way interactions, degree of agreement with the panel mean, degree of discrimination across samples and the residual standard deviation of each assessor by attribute. All assessors were found to be performing to an acceptable standard according to values based on long standing measures developed over time.

The trained panel data were analysed by analysis of variance (ANOVA) using XLSTAT (Addinsoft, 2020, Paris, France). The effects of the wine, assessor, assessor by wine, presentation replicate, assessor by presentation replicate and wine by presentation replicate were assessed, treating assessor as a random effect. Following ANOVA, Fisher’s least significant difference (LSD) value was calculated (P = 0.05) for the wine effect. An additional principal component analysis (PCA) was conducted for the QDA data of the means of the wines of the significant (P < 0.05) and close to significant (P < 0.10) attributes using XLSTAT.

For the consumer liking data, ANOVA was carried out using Minitab 20 (Minitab Inc., Sydney, NSW) and XLSTAT for each cultivar separately. The effects of the wine and assessor were assessed. Following ANOVA, Fisher’s LSD value was calculated (P = 0.05) for the wine effect.

Agglomerative Hierarchical Clustering (AHC) was run using Wards method in XLSTAT, and a one-way ANOVA model involving liking scores of the wines as a fixed factor was performed on the groups generated by AHC, with additional LSD on subsequent clusters. A correlation matrix was produced using XLSTAT for the Shiraz wines to determine if there were any other drivers of liking amongst the consumer clusters.

RESULTS Shiraz wines

For the Shiraz sample set, a full QDA was completed.

In addition, the QDA data were compared with results from SRP assessments. The QDA data demonstrated that 13 attributes differed significantly among the eight wines. These were ‘opacity’, ‘purple’, ‘dark fruit aroma’, ‘blackcurrant aroma’, ‘eucalypt aroma’, ‘smoke aroma’, ‘spices aroma’, ‘eggy/drain (reductive) aroma’, ‘astringency’, ‘hotness’, ‘viscosity’, ‘overall fruit flavour’ and ‘smoke flavour’. Only ‘smoke flavour’ was significantly different for the presentation replicate effect. There were significant (P < 0.05) assessor-by-wine interaction effects for several attributes.

The sensory attributes of the Shiraz wines that were significantly different were visualised using PCA, shown in Figure 1.

The first two principal components explained 51.4% and 31.5% of the variance. The ‘smoke aroma’ and ‘smoke flavour’ attributes were closely correlated (r = 0.93, P < 0.001), with SHZ G and SHZ C wines rated highest in these attributes, situated in the bottom left quadrant of the PCA (Figure 1), and these wines were rated low in most other attributes,

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suggesting the ‘smoke flavour’ suppressed other aroma and flavour attributes. Conversely, the wines made from grapes grown from vineyards with no smoke exposure, SHZ A and SHZ B, were rated lowest in the smoky attributes, plotted in the top right quadrant of Figure 1. Wines SHZ A, SHZ B and SHZ D were highest in ‘dark fruit aroma’, with SHZ D and SHZ B and SHZ I high in ‘opacity’, ‘astringency’, ‘overall fruit flavour’ and ‘spices aroma’. SHZ K was rated moderately in smoke and most other attributes and was plotted towards the centre of the PCA. One wine, SHZ F, had relatively high smoke intensity but was also high in ‘eggy/drain aroma’ (sulfur related off-odour), while SHZ I rated highly in ‘smoke aroma’ and ‘smoke flavour’ and notably high in ‘eucalypt aroma’, ‘blackcurrant aroma’ and ‘hotness (alcohol burn)’.

The SRP procedure also demonstrated that there were significant differences (P < 0.001) among the wines for each attribute: ‘overall fruit aroma’, ‘smoke aroma’, ‘overall fruit flavour’ and ‘smoke flavour’. SRP assessors were a significant source of variation (P < 0.05) for ‘overall fruit aroma’ and ‘overall fruit flavour’. Assessor-by-wine interaction was a significant source of variation for ‘smoke aroma’ (P < 0.05) and ‘overall fruit flavour’ (P < 0.01) (data not shown).

There was a strong correlation between the ‘smoke aroma’ and ‘smoke flavour’ ratings from the QDA assessment and the specific SRP procedure: ‘smoke aroma’ (QDA) vs ‘smoke aroma’ (SRP), r = 0.97 (P < 0.001); ‘smoke flavour’ (QDA) and ‘smoke flavour’ (SRP), r = 0.91 (P < 0.01), as illustrated in Figure 1, with smoke flavour ratings from the SRP plotted as a supplementary variable.

With both methodologies, SRP and QDA, the wines SHZ C, SHZ F, SHZ G, SHZ I and SHZ K were significantly higher (P < 0.05) in ‘smoke flavour’ than the control wines (SHZ A and SHZ B). The smoke-affected wines were rated low for ‘overall fruit aroma’ and ‘overall fruit flavour’. Wines SHZ A and SHZ B were significantly different from one another for ‘overall fruit aroma’ and ‘overall fruit flavour’. For both studies only the wines SHZ C, SHZ F and SHZ G were significantly higher than the controls for ‘smoke aroma’. As expected, the control wines had non-zero scores for smoke attributes for both studies, notwithstanding the extent of panel training.

For the SRP methodology, wines SHZ A and SHZ B had relatively low ‘smoke flavour’

mean scores of 0.74 and 0.39, respectively, while for the QDA approach the values were 1.92 and 1.70.

To complement the expert panel sensory data, a subset of six Shiraz wines spanning the range of smoke flavour intensities from low to high was tasted by 111 red wine consumers,

with the liking data shown in Figure 2a. Wines SHZ B and wine SHZ D, which were chosen as controls for the consumer study, were well accepted (as indicated by liking scores above 6.0), with all other wines rated significantly lower in liking. The least liked wine, SHZ G (Figure 3a, see page 32), had the highest

Figure 2. Consumer response to wines with various smoke exposed vineyards (a) Consumer liking mean scores (b) Shiraz Principal Component Analysis biplot of the mean liking scores of three identified clusters and the total sample shown as vectors. The six wines are shown in blue. The sensory attributes from the QDA are indicated in black, as well as the smoke rating assessment attributes shown in purple. PC = Principal Component, A = Aroma, F = Flavour, SRP = Smoke Rating Panel.

Figure 1. Principal Component (PC) biplots of significant sensory attribute means from the Shiraz wines for PC1 and PC2. Significance levels are as follows: *P≤0.05; **P≤0.01; ***P≤0.001.

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‘smoke flavour’ intensity and the wines with smoke flavour rated above 1.95 from the SRP procedure were significantly less liked than the control wine.

Agglomerative hierarchical clustering analysis was performed to explore if clusters of consumers existed amongst the 111 participants. Three clusters were identified with significantly different liking scores (P < 0.05) within each cluster. The consumer liking data for each cluster and for the total consumer group tested was related to the sensory data by internal preference mapping (Figure 2b) using the mean liking scores of each cluster and of the total sample.

The mean liking scores for the total consumer group were strongly negatively correlated with the intensity of the smoke attributes from the two procedures (r < -0.96).

The total consumer group liking score versus ‘smoke flavour’ rating from the SRP methodology is presented in Figure 3a.

The mean liking scores were significantly positively correlated with the QDA attributes ‘opacity’, ‘purple’, ‘dark fruit aroma’, ‘astringency’, ‘viscosity’ and ‘overall fruit flavour’ (r values from 0.81-0.96), and the SRP attributes ‘overall fruit aroma’ and ‘overall fruit flavour’ (r = 0.99).

Clusters 1 (28% of consumer) and 2 (53%) showed similar patterns of liking as the overall group of consumers (Figure 2b), with each showing a strong negative correlation with the smoke attributes (for example, cluster 1 mean scores vs smoky flavour, SRP, r = -0.92, P<0.01) and strong positive correlation with the attribute ‘dark fruit aroma’ (r>0.91, P<0.05), with moderate correlations (r>0.75, P< 0.1) of liking scores for ‘opacity’, ‘purple’, ‘viscosity’, and ‘overall fruit flavour’. The responses of clusters 1 and 2 were similar, although cluster 1 liking scores were lower overall than those of cluster 2; the SHZ D wine was significantly less liked than the control wine SHZ B; and there were notably low liking scores of approximately 3.0 for SHZ F, SHZ C and SHZ G.

Cluster 3 (19% of consumers) had a different pattern of liking compared to the other two clusters, with SHZ B, a control wine with no known history of smoke exposure, scored lowest. No strong correlations of the liking scores of this cluster were found for any of the sensory attributes. This was a small cluster, and there was a significant presentation order effect which might explain the differences in liking for this cluster compared to the others,

with wines presented earlier generally receiving higher scores for liking, as reported previously (Hottenstein et al. 2008).

Consumers in Cluster 1 (28% of consumers) showed significantly lower liking scores of each of the smoke exposed wines compared to the control wine (SHZ B), which was scored above 6.0, with all other wines having mean values less than 5.0. Wines SHZ C, SHZ F, SHZ G and SHZ K received similar low hedonic scores (below 4.0). Similar to the total group of consumers, the attributes ‘opacity’, ‘dark fruit aroma’, ‘astringency’ and ‘overall fruit flavour’, were positively correlated with liking for this cluster. ‘Spices aroma’ was also significantly positively correlated.

Pinot Noir rosé

For the Pinot Noir rosé wine set, all wines were assessed using the specific SRP methodology. There were significant differences (P<0.05) among wine blends for the four attributes rated by the panel,

namely ‘overall fruit aroma’, ‘smoke aroma’, ‘overall fruit flavour’ and ‘smoke flavour’. The PNR 100% smoke-affected wine, the PNR 50% blend, and the PNR 25% blend were rated significantly higher (P<0.05) in ‘smoke aroma’ and ‘smoke flavour’ than PNR 0% and were rated low for ‘overall fruit aroma’ and ‘overall fruit flavour’. PNR 12.5% and PNR 6.25% were not rated significantly different from the unaffected PNR 0% wine for any of the attributes. The PNR 6.25% had slightly higher ‘overall fruit aroma’ and ‘overall fruit flavour’ scores than PNR 0%, although not by a statistically significant margin. The ‘smoke aroma’ and ‘smoke flavour’ scores were highly correlated (r = 0.998, P < 0.001). As the PNR 50% wine had similar high smoke flavour rating to the 100% blend, it was decided that this wine could be excluded from the consumer study to reduce the number of samples presented to the consumers in an attempt to avoid fatigue.

From the consumer test, the least liked wine was the PNR 100% wine (Figure 3b).

Figure 3. The relationship between the mean sensory smoke flavour intensity and the mean consumer liking for a) SH = Shiraz (R2 = 0.954**; y = -0.34x + 6.55), b) PNR = Pinot Noir rosé (R2 = 0.945**; y = -0.66x + 7.14) and c) CHA = Chardonnay (R2 = 0.968**; y = -0.17x + 6.74). **P≤0.01.

The blend of 25% of the smoke-affected wine with 75% of the unaffected PNR wine was liked significantly more than the PNR 100% wine. There were similar liking scores for the PNR 0%, PNR 6.25% and PNR 12.5% wine.

As observed for the Shiraz wines, the liking scores for the PNR wines showed a strong negative linear relationship (R2 = 0.95, P<0.01) with the smoke flavour ratings. There was also a linear relationship between smoke flavour intensity and the proportion of smokeaffected wine. There was some evidence that clusters of consumers existed amongst the 82 participants in the PNR consumer study. The data indicated that there was a group less accepting of smoke flavour, a moderately negatively responsive group and group of non-responders.

Considering the relatively small number of consumers in each cluster, the PNR clustering data were not analysed in greater detail.

Chardonnay

For the smoky Chardonnay wine blended with increasing proportions of an unaffected Chardonnay, there were significant differences (P<0.05) among the wines for ‘smoke aroma’, ‘overall fruit flavour’ and ‘smoke flavour’. Assessors were a significant source of variation (P<0.001) for ‘overall fruit aroma’ and ‘overall fruit flavour’. Assessorby-wine interaction was also a significant source of variation for ‘overall fruit aroma’ (P<0.05) and ‘smoke aroma’ (P<0.01) (data not shown).

The CHA 100% smoke-affected wine was rated significantly higher (P<0.05) in ‘smoke aroma’ and ‘smoke flavour’ than the CHA 0% wine by the smoke rating panel and was lowest for ‘overall fruit flavour’.

The blend with 50% smoke-affected wine was rated significantly higher than the unaffected wine for ‘smoke aroma’ and ‘smoke flavour’. Wine CHA 25% was significantly higher but only in ‘smoke flavour’ than the unaffected wine. The blends with less than 25% smoke-affected wine had ‘smoke flavour’ ratings of 1.01 and 1.36 and were not significantly different from the unaffected wine for any of the attributes. The unaffected wine had ‘smoke aroma’ and ‘smoke flavour’ values of 1.16 and 1.44, respectively.

As observed for the Shiraz and Pinot Noir rosé wines, the ‘smoke aroma’ and ‘smoke flavour’ attributes of Chardonnay wines were highly correlated (r = 0.97). As no difference was found between CHA 0%, CHA 6.25% and CHA 12.5%, it was decided that CHA 6.25% would be excluded from the consumer study to avoid fatiguing consumers and collecting superfluous data.

From the consumer test, the least liked Chardonnay wine was the smoke-affected wine, CHA 100%, with the blend of 50% of the smoke-affected wine also less liked than the unaffected wine (Figure 3c). There were similar liking scores for the CHA 0% (0% smoke-affected) wine, CHA 12.5% and CHA 25% wines. The liking scores showed a

strong negative linear relationship (R2 = 0.97, P<0.01) with the smoke flavour rating. The Chardonnay wines with smoke flavour rated above 2.47 were significantly less liked than the control wine.

There was strong evidence that clusters of consumers existed among the 124 participants of the Chardonnay study.

Cluster analysis identified three groups of consumers with significantly different liking scores (P<0.05) within each of the clusters. Cluster 1 (21% of consumers) most liked the clean control wine, and this cluster had progressively lower liking scores for the wines blended with increasing proportion of smoke-affected wine. There was no significant difference between the CHA 0% and CHA 12.5% wines in liking by cluster 1, although CHA 25% was liked significantly less than the clean wine. The CHA 50% and CHA 100% blends had very low liking scores.

For Cluster 2 (38% of consumers) all the wines were well accepted (mean liking scores above 6.0) with only the CHA 100% wine significantly less liked than the other wines. For the largest cluster (Cluster 3 –40% of consumers) there were no significant differences between any of the wines.

This suggests that they were either not sensitive to the smoke flavour or accepted the characteristics it provided. Still, this cluster reported significantly lower purchase intent for the wines with a higher proportion of smoke-affected wine in the blended product (data not shown).

As found with the Pinot Noir rosé, there was a linear relationship between smoke flavour intensity and the proportion of smoke-affected Chardonnay wine, however the R2 value was lower.

DISCUSSION

The results clearly show that smoke flavour was a strong negative driver of consumer liking in all three wine styles.

The Shiraz wine sample set, which comprised a range of wines all produced using the same winemaking procedure from grapes with varied exposure to smoke from nearby forest fires, were evaluated using a QDA approach and a specific smoke rating methodology. The smoke attribute results were very similar with both methodologies.

The correlation between the SRP data and the QDA panel’s smoke aroma and flavour ratings was very strong (r>0.94), which is not surprising considering both panels were selected based on successful smoke sensitivity screening procedures and had received training prior to formal evaluations. There were lower mean ratings for the controls from the specific SRP method, indicating fewer ‘false positive’ non-zero scores given by the assessors for unaffected wines compared to a generic QDA panel approach. It is expected that even with a highly trained, screened and experienced sensory panel, ‘falsepositives’ can occur. This can be due to an expectation effect by the assessors (Meilgaard et al. 2016), and the presence of confusable characters in the wines. To effectively allow for an assessment of the magnitude of a smoke rating that can be considered significant in an industrial application, an unaffected control wine should always be included in the sample set. Overall, the time required for one SRP assessment (2 hours total) compared very favourably to that required for one QDA (12 hours), given the almost identical results.

Both the SRP assessments and QDA (with smoke sensitive assessors) for the Shiraz wines showed very strong predictive ability when comparing consumer liking to smoke flavour intensity ratings from the trained expert panels. As smoke aroma and smoke flavour were highly correlated in each study, but smoke flavour showed greater discrimination, it was a better overall predictor of consumer liking. The results of the QDA indicated that wines with smoke aroma and flavour were less intense in fruity attributes, such as dark fruit or

blackcurrant, suggesting a suppressive effect of the smoke flavour as previously indicated (Parker et al. 2012).

Consumer liking was highly negatively correlated with smoke flavour intensity for each wine type (Figure 1), independent of the varietal, winemaking and matrix differences between the Shiraz red wines, Pinot noir rosé wines and Chardonnay white wines. The mean smoke flavour score that significantly affected consumer liking was different between the three different wine styles, with different slopes of the regression fitted lines across the wine types.

This suggests the involvement of matrix effects influencing the absolute magnitude of the smoke flavour rating and therefore consumer liking. The Chardonnay wine set had the shallowest slope, with the CHA 100% affected wine receiving a mean smoke flavour rating of approximately 5.1 on the 10-point scale and a relatively high liking score of 6.5.

In contrast, in the Shiraz and Pinot Noir rosé sets, the wines rated highest for smoke flavour intensity had liking scores well below 5.0. Higher smoke flavour was thus tolerated in the Chardonnay, possibly because ‘toasty/ oaky’ and ‘struckflint’ characters are generally well liked and accepted as part of this wine style (Iland et al. 2017), which may be confusable for most consumers.

While a relatively small number of consumers were used in these studies, evidence of clusters of consumers were found for each wine type: a more responsive group of consumers (21-46%), a moderately responsive group that closely mimicked the total group (33-53%), and a group that were not responding to smoke flavour (19-40%). The size of each of these clusters was different between each consumer group and wine style, but the same classifications were found each time.

Blending a heavily smoke-affected wine with a ‘clean’ wine using a dilution-to-threshold approach was used partly to expand the study, as obtaining a range of smoke-affected grape lots can be difficult given the unpredictable nature of wildfires. The approach also allowed assessment of critical levels of smoke flavour intensity with fewer confounding variables. The approach has the drawback that it is difficult to definitively exclude other confounding sensory attributes that might have contributed to differences in consumer preferences in the blends. The different blends obtained can be

considered separate wines with increasing smoke aroma and flavour, but with other possible sensory differences.

In this study, careful consideration was applied to select for dilution appropriate ‘clean’ wines with similar basic chemical composition. The observed linear negative liking response with increasing smoke flavour ratings for each of the three wine sets studied provides reassurance that the smoke flavour caused the negative consumer response, independent of wine style.

Across all three studies, non-zero ratings were observed for the ‘clean’ control wines in the smoke rating SRP and QDA assessments. Smoke flavour values for the control wines ranged from 0.74 to 1.92, and we assume that these smoke flavour ratings in ‘clean’ wines reflect their typical wine composition and are not due to experimental artifacts from carry-over effects. For both methods, enforced resting periods were used to allow a) enough time for the flavour to develop and b) avoidance of carryover effects due to long lasting smoky aftertaste, which have been problematic in smoke wine assessments (Fryer et al. 2021, Oberholster et al. 2022).

Both panels had a two-minute break between samples, and in the SRP assessments, flavour attributes were rated after 30 seconds to ensure that there was sufficient time to allow the flavour to be perceived, rather than for the perception of smoke to be perceived in the break between samples.

One benefit that the SRP methodology has over conventional QDA is the potential to be a much faster and more economical way to assess the risk of smoke taint for industry. Provided robust screening and training procedures are implemented, the SRP process would be a better option for industry to adopt as sessions can be implemented more rapidly.

This methodology was tested with a regional winemaker panel, with good agreement with the results with the data obtained in this study (r = 0.98) and could be adopted more broadly by wine companies or regional organisations (data not shown).

The main benefit of the QDA assessment over the SRP assessment is that the whole range of appearance, aroma and palate attributes is measured, which allows deeper insight into the influence of masking and enhancing sensory characteristics across the wines. The QDA results revealed interactions

of smoke aroma and flavour with other elements in the wine, such as alcohol heat, acidity, sweetness and other attributes that can play a role in the intensity of smoke flavour.

An interesting sample was SHZ I, which contained high concentrations of smoke marker compounds, but received moderate ‘smoke aroma’ and ‘smoke flavour’ scores by panellists, both for the QDA and SRP. The QDA revealed that this wine had a ‘eucalyptus aroma’, ‘blackcurrant aroma’ and was high in ‘hotness (alcohol burn)’, which potentially could be suppressing the smoke aroma and flavour in the wine.

The SHZ I wine was found to contain a high concentration of the eucalyptus/minty compound 1,8-cineole (19.8μg/L, well above its sensory threshold of 1.1μg/L (Herve et al. 2003)), the blackcurrant-like compound dimethyl sulfide, (21.2μg/L, which has a sensory threshold of 1.74μg/L) (Lytra et al 2014) and was high in alcohol (16.5%v/v). More research is warranted to establish and better understand masking effects in wine, which might provide an approach to guide the selection of particularly suitable blending wines.

Depending on the commercial considerations of individual wine producers, some companies might prefer not to risk releasing any even slightly smoke-affected products to the market, given the strong relationship between smoke aroma and flavour score, and reduced consumer acceptance. Others may make use of the results of this study to develop a guide regarding limits of smoke flavour above which consumer acceptance is significantly reduced, such as described in Hough et al. (2002). Further wine styles will need to be investigated to assess whether the results obtained in this study are applicable more generally. Also, sensory assessment and predictive modelling of combinations of smoke-related compounds need to be established to determine the size of the risk that winemakers and producers will face when smoke events occur. The chemical composition of smoke-affected wines and the relationships with wine flavour are discussed in detail in a separate accompanying manuscript (Parker et al. 2023). Reconstitution experiments will need to be specific for individual wine cultivars and winemaking practices. Until then, robust sensory

assessment of wine and chemical measures of smoke exposure markers are necessary to identify and gauge a potential risk of quality defects after smoke exposure of vineyards.

CONCLUSION

From all three studies, it is clear that consumers respond negatively to smoke flavour in wine that is caused by vineyard exposure to wildfires and smoke events. The sensitivity of consumers to smoke-affected wines correlated highly with smoke flavour ratings from a screened and trained smokesensitive panel. While the overall group of consumers in each study showed a strong negative correlation between liking and smoke flavour, there were clusters of consumers that were more sensitive to these characters.

The response to smoke flavour was variable across the different wine styles. However, the wines that showed a negative response from consumers all had concentrations of smoke marker compounds lower than that of the reported sensory thresholds for all individual compounds.

With a maximum acceptable concentration of smoke marker compounds not currently

known, it will be crucial for the wine industry to incorporate both sensory and chemical analysis for making decisions post-smoke events. Research investigating the way in which these phenolic (and potentially other) flavour compounds interact with one another, and the complexity of the background matrix of the grape cultivars and wine styles, will also be important in solving this issue.

Overall, the information from the present study will enable grapegrowers and winemakers to make better informed business decisions about reducing or eliminating potential quality defects after smoke events.

FUNDING

This work was performed by the AWRI, a member of the Wine Innovation Cluster in Adelaide, South Australia. Funding was provided by Australian grapegrowers and winemakers through their investment body Wine Australia, with matching funds from the Australian Government. Additional funding and in-kind contributions from PIRSA, the South Australian, Victorian and NSW state governments, Wine Victoria and NSW Wine, and the Australian Government’s Department of Agriculture and Water Resources Rural R&D for Profit program are gratefully acknowledged. External funders were not involved in the study design, collection of data, analysis and interpretation of data, writing the report, or the decision to submit the article for publication.

ACKNOWLEDGEMENTS

The authors would like to acknowledge Affinity Labs for analysis, Kantar Australia for screening consumers for the Chardonnay study, and use of their facilities in Melbourne, Peter Leske and the Adelaide Hills winemakers, and the AWRI sensory panellists for their smoke rating and descriptive evaluations. Additional thanks to Patricia Williamson, Desireé Likos, Damian Espinase Nandorfy, Sheridan Barter, Ella Robinson, Con Simos and Mark Krstic for their assistance. The authors would also like to thank the industry partners who provided access to vineyards and samples for analysis, and finally the numerous staff at the AWRI involved in smoke analysis.

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This article was first published online by OENO One, DOI: https://doi.org/10.20870/ oeno-one.2023.57.2.7261

Vintage 2023 – observations from the AWRI helpdesk

By

Mark Krstic

The AWRI helpdesk responds to technical issues encountered by Australian grapegrowers and winemakers, identifies the root causes of problems and provides research-based, practical solutions. Monitoring the trends in technical issues encountered across the nation’s wine regions over the growing season is a useful way to identify when information or assistance is required, at either a regional or national level. Support is then provided via channels including eBulletins, the AWRI website, webinars or face-to-face regional extension events. This article examines some of the conditions experienced across the nation leading up to and during vintage 2023, and some of the technical challenges encountered.

VINTAGE 2023 AT A GLANCE Identifying key technical issues

The AWRI helpdesk, funded by Wine Australia, provides free confidential advice and support to Australian grapegrowers and winemakers and is in a unique position to track the technical issues that emerge each vintage. During vintage 2023 (between 1 January and 1 May) the helpdesk received more than 517 enquiries (Figure 1) and conducted 56 small-scale investigations to identify the underlying cause of problems reported by winemakers and growers.

Cool and wet growing season in the east Australia’s third La Niña event in as many years re-developed in early September 2022 and continued through to the end of 2022. A negative Indian Ocean Dipole (IOD) was present in winter and spring which resulted in above-average winter/spring rainfall over parts of southern Australia, as the warmer waters off north-west Australia provided more available moisture to weather systems crossing the country. The Southern Annular Mode (SAM) remained positive throughout spring and summer, also bringing cooler and wetter conditions. The 2023 growing season is now

IN BRIEF

■ Australia experienced its third La Niña in a row, causing cooler and wetter conditions and a delayed harvest in the south-eastern wine regions

■ Oversupply pressures drove mothballing or resting of some vineyards

■ Record rainfall and floods affected both vineyards and wineries

■ Weather conditions heightened disease pressure

■ Early prescribed fuel reduction burns began in March, coinciding with the delayed harvest

■ Producers experienced limited availability and/or increased costs of fungicides, urea, DAP and carbon dioxide

■ Wine Australia’s national vintage survey estimated a record low Australian winegrape crush of 1.32 million tonnes, 26% below the 10-year average of 1.78 million tonnes, and the lowest reported crush since 2000, driven by both climate and market factors.

Ben Cordingley, Adrian Coulter, Geoff Cowey, Robyn Dixon, Marcel Essling, Matt Holdstock, Mardi Longbottom, Chris Penfold, Liz Pitcher, Christa Schwarz, Con Simos and Mark Krstic, Australian Wine Research Institute, PO Box 197, Glen Osmond, South Australia 5064

Photo: Barossa Australia

the fourth in a row with a positive SAM. The combined cooler and wetter climate drivers, along with high soil moisture content across central and eastern Australia, delayed flowering until December in many regions, which in turn delayed berry development and resulted in a delayed or late harvest. For many regions, this will go down as one of the latest seasons in recent times. The delayed start to the season and cool and wet seasonal conditions, including flooding, also saw increased prevalence of and questions about pest and disease pressures during spring and early summer, with these queries not included as data in Figure 1 as they were received prior to 1 January 2023.

Spring temperatures were below or very much below average across nearly all of mainland Australia. For New South Wales, the spring mean maximum temperature was the fifth-lowest on record (compared to all springs since 1910) and the lowest since 1976, while in Victoria it was the sixth-lowest on record and lowest since 1992. A large number of weather stations across the Murray–Darling Basin had their coolest spring daytime temperatures on record. National mean summer temperatures were only 0.07°C above the 1961-1990 average, but much lower than summer temperatures of more recent times between 1990 and 2020.

Spring rainfall was 112% above the 19611990 average for Australia as a whole. Spring was the wettest on record for New South Wales (previous record 2010), Victoria (previous record 1992) and the Murray–Darling Basin as a whole (previous record 2010). Widespread and significant flooding was experienced across large areas of eastern Australia throughout spring. Flood events continued through summer as spring floodwaters travelled through the Murray and Darling River systems in western New South Wales and South Australia. Flooding also affected parts of Queensland and Tasmania.

South-west Western Australia also experienced a cool spring, after a cold winter, but this was followed by a consistent warm summer with minimal rain and no significant heat extremes. This saw maturity occur in line with long-term averages and with low disease pressure, resulting in an optimal vintage.

Flooded vineyards and wineries

The increased rainfall in 2022 caused flooding across central and eastern state wine regions. As floodwaters progressed along the Darling and Murray rivers, vineyards close to the river became submerged. In some instances, severe flooding washed away vineyard

infrastructure, which will require vineyard reestablishment. Where there was persistent flooding, or where floodwaters took time to recede, waterlogging in vineyards became a concern. Rising water tables also resulted in some vineyards affected by rising salinity. Wineries located close to rivers also became flooded, with the helpdesk asked to investigate affected wine stock in both bottles and barrels.

The effects of waterlogging occur when a grapevine’s root zone becomes saturated and the air between the soil particles is replaced by water. Grapevine roots require oxygen for respiration, and a lack of oxygen over an extended period can result in root death and eventually vine death. The absence of oxygen in the soil and around the roots triggers a cascade of physical, biological and chemical processes, the results of which can also have a negative effect on vine performance. To assist growers dealing with waterlogged vineyards, the AWRI produced a new fact sheet providing advice on monitoring and remediation.

Increased disease pressure

The wet seasonal conditions and widespread flooding saw increased queries about the control of downy mildew and botrytis.

Figure 1. Winemaking and viticulture enquiries received by the AWRI helpdesk between 1 January and 1 May 2023, organised by keywords. Enquiry numbers are represented as a percentage of the total winemaking and viticulture enquiries during the vintage period, where the total number was 517

Applications for emergency use or temporary permits for agrochemicals were prepared and communicated through the AWRI’s Agrochemicals project. Several eBulletins warning about disease pressure, downy mildew and fungal diseases were distributed at the start and mid-way through the season and a webinar was presented on managing botrytis in the vineyard.

Bacterial inflorescence rot

Cases of necrosis and rot of inflorescences were also reported this season. These symptoms could be caused by a physiological disorder or fungal infection, but could also be the result of bacterial inflorescence rot (BIR), which is caused by the bacterium Pseudomonas syringae pv. syringae (PSS). This is a low-risk pathogen in dry and warm seasons, but its development and spread are favoured by wet conditions such as those experienced this year. A fact sheet and eBulletin were produced to raise awareness about this disease, with information on testing and steps to take when pruning affected vines. Actions to open the canopy and promote airflow were encouraged.

Mothballing/vine resting

This year several regions requested information and assistance regarding mothballing or resting vineyards as a way of addressing the impacts of over-supply pressures. Viticulturists attended regional meetings on this topic in the Riverland and Langhorne Creek and an ‘Ask the AWRI’ article — published in the Grapegrower & Winemaker, sister publication to the Wine & Viticulture Journal — summarised key information for producers. The application of ethephon and calcium nitrate to reduce yield were investigated and permits were obtained from the regulatory agency to facilitate their use.

Prescribed fuel reduction burns

Due to the generally wetter year and additional vegetative growth, several states again brought forward prescribed fuel reduction burns to early-to-mid-March, which caused concern for growers whose fruit remained on the vine due to the delayed season. We continue to assist state and regional associations to communicate with forest and fire management authorities about the dangers of controlled burns, especially in a year like this

one where the harvest window was delayed due to the colder and wetter conditions.

Winemaking practices

Queries on how to perform a range of different winemaking practices were higher than usual this season but with no particular trend in terms of topics. Queries covered practices including malolactic conversion in wines with high acidity; yeast assimilable nitrogen (YAN) and nitrogen alternatives; timing of tannin additions; amber wines and skin contact in white wine production; sherry production; fortification; NOLO wine production; addition of oxygen during fermentation; hyperoxidation; clarification and settling issues; yeast culture propagation; and use of agents such as dimethyl dicarbonate (DMDC).

Limited nitrogen in vineyard and winery

Queries about the availability and increased cost of nitrogen fertiliser and additives (urea in the vineyard and diammonium phosphate in the winery) were received from both growers and winemakers. Many food and agricultural sectors had to deal with reduced availability and/or increased cost of nitrogen-based fertilisers and additives for the second year in a row. Australia imports 90% of its nitrogen-based chemicals from India, Morocco and China. Reduced worldwide production of these chemicals due to natural gas being redirected for energy needs has resulted in major export nations such as China and Russia placing restrictions on exports of urea to control prices in their domestic markets. This has increased prices on the international market by a factor of three to four since December 2019. Suppliers were contacted to discuss supply and demand factors and researchers were consulted to discuss alternatives and management techniques. Recommendations were then communicated to the grape and wine sector through two ‘Ask the AWRI’ columns.

Limited carbon dioxide

Carbon dioxide (CO2 or dry ice) was also in short supply this season and around double the usual price. This coincided with the shutdown of the Torrens Island B power station in Adelaide, previously the biggest supplier of CO2 to producers in SA, which also had flowon effects in other states.

HARVEST OVERVIEW – SMALLER VINTAGE BUT OF EXCEPTIONAL QUALITY

Wine Australia’s national vintage survey estimated a record low Australian winegrape crush of 1.32 million tonnes, 26% below the 10year average of 1.78 million tonnes, driven by both climate and market drivers (Wine Australia 2023, and Peter Bailey’s article on page 76). The lower crush is expected to help with wine reserves from the previous seasons. One positive outcome of this year’s cool and late growing season in the east is that most grapes ripened to moderate sugar levels, ensuring moderate alcohols, fine, intense fruit flavours and high, balancing natural acid. Western Australia recorded another optimal growing season and vintage.

LOOKING TOWARDS VINTAGE 2024

Winter 2023 has been much drier than normal for Queensland and the east coast and wetter throughout South Australia and Victoria. Water reserves are still high following three years of wetter conditions. The ENSO outlook is currently on El Niño ALERT, meaning there is approximately a 70% chance of El Niño forming in 2023. There is also a higher chance of a positive IOD during winter. A positive IOD typically suppresses winter and spring rainfall over much of Australia, and if it occurs with El Niño, it can exacerbate the drying effect (BOM Climate Outlook July-September 2023).

ACKNOWLEDGEMENTS

This work is supported by Wine Australia, with levies from Australia’s grapegrowers and winemakers and matching funds from the Australian Government. The AWRI is a member of the Wine Innovation Cluster in Adelaide, South Australia. The authors thank Ella Robinson for her editorial assistance.

REFERENCES AND FURTHER READING

AWRI climate and weather resources: https:// www.awri.com.au/industry_support/viticulture/climateweather-tools/

BOM (2023) Bureau of Meteorology website: www. bom.gov.au/climate/outlooks

AWRI (2022) Managing waterlogged vineyards fact sheet. Available from: https://www.awri.com.au/ wp-content/uploads/2022/11/Managing-waterloggedvineyards.pdf

AWRI (2023) Recognising and understanding bacterial inflorescence rot fact sheet. Available from: https://www.awri.com.au/wp-content/uploads/2023/04/ AWRI-Fact-Sheet-Bacterial-Inflorescence-Rot.pdf

Wine Australia. 2023 Vintage Report. Available from: https://www.wineaustralia.com/market-insights/ national-vintage-report.

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Aerial spraying of vineyards Why you never say never!

By Liz Riley, Viticulturist, Vitibit Pty Ltd, Hunter Valley, New South Wales

Hunter Valley-based viticulturist Liz Riley was presented with the Outstanding Contribution of an Individual Award at this year’s annual Hunter Valley Legends Awards. The award acknowledged her voluntary efforts in coordinating the aerial spraying response in the region after flooding events in 2022 prevented ground spraying in many vineyards across the lower Hunter Valley. We asked Liz to recount her experience with coordinating the technique with a view to informing other growers and regions that may wish to consider it in the future.

When I moved to the Hunter in the early ‘90s I’d heard stories about aerial spraying of vineyards for disease control and I could never quite get my head around why you would do that mid to late season. I really couldn’t understand how you could get coverage and keep disease at bay. So I admit it, I dismissed it out of hand as a poor option for disease control, and didn’t ever give it another thought…until winter 2022.

Winter 2022 saw in excess of 300mm of rain fall in July with major flooding occurring across parts of the lower Hunter, resulting in many vineyards in Broke and parts of Pokolbin being fully submerged. While rainfall was modest in August and September the ground was waterlogged; there was significant debris present within vineyards and there were sites that were inherently unsafe to access. Ground spraying was not going to be an option for many of these sites with budburst rapidly approaching.

A few chats locally saw aerial spraying thrown up and, unlike the good old days, there was a need for this to be planned for and executed in a very careful way. There were several key considerations that came to mind: efficacy (it needed to be effective), legal (what and how we sprayed needed to be legal) and local stakeholders (we aren’t just an agricultural area anymore, we have cellar doors, accommodation, livestock farmers, organic farmers and others who needed to be

engaged in this approach). There was also the question of cost.

It became obvious very early on that the best way to manage all these factors was for it to be a co-ordinated, regional approach to minimise the risk of any ineffective, illegal and inappropriate spraying occurring. This approach was also going to help manage costs with the aerial spraying to be consolidated on particular days.

The initial investigation into options was a huge learning curve and it was obvious that helicopters, rather than fixed wing aircraft, were the better option given the need to fill spray tanks close to vineyards and the need for a landing strip for a plane. That said, we soon realised there was a need to be able to refill the helicopter at short intervals and room for it to gain altitude before turning. We were adding approximately half a tonne of

water and agrochemical and, with the boom attached, this became a key consideration and resulted in various ‘fill sites’ being found around the valley to enable multiple vineyards to be sprayed from one refilling point.

AGROCHEMICAL CALCULATIONS

Agrochemical and application rates became the next big hurdle. We needed to be confident that sufficient water was being applied to cover the small target which was E-L 4-7. While the helicopter could go as low as 40-50 litres per hectare, once we started working out rates and understanding the concentration of chemistry it became necessary to start with 100L/ha to avoid issues with mixing and burn to foliage. Selecting chemistry was important as we were acutely aware that there was a need to make this spraying option suitable for

conventional and organic growers, and for our stakeholders to be confident that we weren’t applying dangerous chemicals by air. Simple chemistry such as copper and sulfur were suitable at this stage as we were chasing protectant cover for early-season disease control, knowing more wet weather was coming. We were able to source organicallycertified copper (Champ WG) and sulfur (Microthiol Dispress) which we calculated spraying rates for and costs for use. It should be noted that in New South Wales we are not permitted to use agrochemicals off label, and label directions must be followed. This precluded many regularly-used products that explicitly stipulated on their labels “not for aerial application” or lacked detail on low volume spraying.

Once we set the 100L/ha water rate we then worked out the chemical rates, making sure these would mix and could be sprayed out without clagging in the tank or blocking nozzles.

Much lower rates of chemical were used than if we had been ground spraying. For example, we would have ground sprayed sulfur at 350L/ha but aerial sprayed at 400g/100L, equivalent to 1.4kg/ha. This would have meant adding 1.4kg into 100L rather than 350L, which sounds reasonable until you realise that all the inputs are mixed in 100L of water which is pushed to the chopper and followed by 300L of clean water to top up the 400L tank on the chopper. Given we were also adding copper to the 100L, we reduced the sulfur rate to 200g/100L, or 0.7kg/ha, which we used for copper hydroxide as well. If we had used higher rates and added in concentration factors, we would have run the risk of mixing and blockage problems.

In parallel to working out the agrochemical logistics, we began working with Commercial Helicopters based in Mudgee. We needed to work through the legal and administration requirements from its perspective as well as how we would decide when to execute a flight. We needed to manage the logistics of the helicopter and support crew (fuel, mixing vehicle and support staff) getting to the Hunter, the weather, the need to not spray on weekends and how many sites were going to need a spray. Site owners needed to do quite a bit of preparation to be able to proceed with aerial spraying and had to obtain permission to spray within 150m of buildings and dwellings on their and neighbouring sites.

Agrochemical is pumped to the helicopter’s spray tank.

Vineyards also had to be plotted electronically into KMZ files and any physical risks added, such as power lines, treelines etc., as well as the site’s physical address.

The Hunter Valley Wine and Tourism Association (HVWTA) was involved at this stage and became the conduit to the local grower community to advise on planned flights and the booking process. Once we had firm bookings, we then had to plan our fill points to minimise the travel time between loads for the chopper and ensure we had lots of water and room for take offs and landings. The Hunter has many small sites with mountains, hills and gullies around them, so this was more challenging than one would think! Agrochemical was sourced collectively to ensure that the right inputs were used and that all mixing would work as planned. The agrochemical then needed to be divided up and delivered to the multiple fill sites ahead of each flight.

READY FOR TAKE-OFF

Prior to the first flight, the HVWTA helped to co-ordinate posts via social media to all the local community pages to ensure the wider community was aware of what was occurring and why. We were very transparent about the reasons (lack of access and need for disease control to protect a potential crop), the timing (when conditions were suitable) and what was being sprayed (organic copper and sulfur). This proved to be a very effective means of communication and was used for subsequent flights.

The first flights were carried out on 7 September and four more flights followed at 10-14 day intervals. While our initial thinking had been that there would be just two or three flights, subsequent rain and ongoing water draining out of the mountains saw many sites remaining impassable, or in need of minimal ground traffic to preserve safe access as the season progressed. Some growers did a combination of aerial and ground spraying which enabled them to apply chemistry that wasn’t suitable for aerial application, such as phos acid and caterpillar controls.

We increased water rates to 150L/ha as canopies grew and watersensitive paper was used on most flights to assess coverage. The pilot was very receptive to the coverage feedback and adjusted the nozzles, swathes etc to ensure the best coverage possible could be achieved.

Some sites remained impassable after the fifth flight and crops were not successfully taken to harvest, but they did have good wood to work with for the next season. Many of the blocks were successfully harvested with the aerial spraying proving to be very useful from a crop protection angle but also helping to minimise soil compaction and reduce the work health and safety risks that go with working on soft and slippery ground with machinery. The weather did improve during the back end of the season and the aerial spray application definitely kept a number of growers in the game until things warmed up and dried out.

MOVING FORWARD

Some of the key learnings from this undertaking of aerial spraying included the need to consider the chemistry and the rates that need to be applied once ground spraying resumes, noting that we were potentially underdosing with the low rates applied by aerial application. Those growers who were able to return to ground spraying and apply post infection sprays and use the desired higher rates of fungicide achieved better results.

A close-up of the boom spray.

If you think you may need to spray aerial can you please:

• Complete the commercial helicopter service agreement.

• Obtain permission to fly within 150m of a building/dwelling from all relevant neighbours.

• Supply a map with ALL blocks that may need to be sprayed — this is not a commitment to spray but enables us to prepare KML files to be uploaded to the pilot’s computer. We will get you to confirm which blocks are in or out the day before.

• Supply the street address where the helicopter and engineer can arrive with gear.

Water supply/mixing/landing/takeoff areas:

• Please advise regarding water supply and take off/landing locations — approx. 40-50m clear area.

• Please let us know if you have a water supply with a 1.5-2 inch water connection or a dam where water can be drawn from — ideally with a clear 40-50m area for landing and take off.

• If you don’t have a water supply can you supply shuttles e.g. multiple 100L IBCs of water that can be placed in the landing area which can have water sucked out of them for rapid filling.

• Filling for adjacent properties will take place from one location but the ground mixing rig will move if properties are spread out to reduce flying time for refills and to optimise spraying time.

Timing

• We are endeavouring to only spray on weekdays.

• Days selected are based on the best weather and the need to spray i.e. growth and weather based disease risk.

• Timing on the day will depend on if it is windy in the location and other locations and orders will change to ensure that we spray under suitable conditions.

Chemistry

• The chemistry is strictly sulfur (Microthiol dispress at 200g/100L) plus copper (Champ WG at 95g/100L) if required, at a water rate of 100L/ha therefore with a concentration factor of 3.5.

• This will be supplied on your behalf, and you will be invoiced in due course.

• Approx. cost for sulfur is $2.10/ha and copper is $8.25/ha = say $10.50/ha to allow for some losses, mixing etc…

BOOKING IN

The sooner we know you are ready for spraying and the likely blocks and area, the sooner we can organise a spraying run –noting that we are trying to avoid weekends. We will email when flights look likely so we can book the helicopter and work out mixing/refill sites and the volumes of chemical needed.

Please be responsive and advise if you are in or out and which blocks need what to be applied.

There are a lot of moving parts so timely communication is paramount to make this work for everyone. Last minute inclusion without maps make this harder and more likely to not occur.

To provide some context for the level of disease pressure that was present, there were five or six downy mildew primary infection events between budburst and flowering, so while the aerial application was very good, it was not as good as ground spraying under these conditions. This was, in part, due to the fact that we couldn’t always spray at the ideal time given we weren’t spraying on weekends and had to work around the weather and helicopter availability.

So, I now consider helicopters as another tool in my toolbox for crop protection. I hope I don’t need to pull it out again, and I would be reluctant to use it for a whole season as achieving the necessary coverage — both dose and physical coverage — would be an issue.

Another key learning was that it is vital to work with experienced operators when doing an exercise such as this. Their attention to detail to ensure the coverage was right, covering off on the pre-flight paperwork and the post-flight spray diaries was very

reassuring and made a material difference to the outcomes.

The cost of aerial spraying small areas with an out-of-region provider is not insignificant. We were very fortunate that grants were available for eligible growers via the Rural Assistance Authority to assist with flood recovery and this included the use of aerial spraying.

This exercise would not have been possible without the support of the HVWTA (in particular Jennie Curran and Julia Moore), the NSW DPI, and the NSW Wine Industry Association. Thanks must also go to Scott Patton, from Nutrien, who provided sound technical guidance and support as we were formulating our plans, and to both local resellers Ace Ohlsson and Nutrien for sourcing and delivering agrochemicals around the valley as needed. On a personal note, a huge thanks to Jerome Scarborough for his unwavering support as we executed this project through spring 2022.

Water-sensitive paper was used on most flights to assess spray coverage.

Logistics guidance issued to Hunter Valley vineyards utilising helicopter spraying in the 2022-23 season

Spotlight Plus® saves time and money for Griffith viticulturist

The switch away from mechanical to chemical sucker control has rewarded Griffith viticulturist and contractor Steven Barbon with major savings.

Barbon has 90 acres of grapevines on a property just south of Griffith, in the Riverina region of New South Wales.

Suckers are an annual problem in the vines and, historically, were manually removed with machetes or knives.

“We were out in the heat, had issues with snakes and had to be careful that we didn’t cut any drip tape. I think it was costing us about $10,000 in labour to go across our 90 acres,” he explained.

In more recent times, Barbon purchased a Pastro Custom Ag De-suckering Vineyard Sprayer and has been applying Spotlight Plus® Herbicide from FMC ever since.

“It now takes about one and a half days to do the 90 acres with just two containers of Spotlight Plus.”

He said the machine had an electric eye that identified the trunk of the vine and then sprayed down to the base.

Spotlight Plus is generally used from midOctober through to early November and is applied when a few suckers first appear in the vineyard.

“It does a really good job controlling unwanted suckers,” he said.

“We have had really good results. I can spray in the morning and by the afternoon you can see the green tissue of the suckers starting to wilt.”

The herbicide is used on a wide range of winegrape varieties including Shiraz, Pinot Noir, Pinot Gris, Chardonnay and Merlot on the home block.

Barbon also contracts to other vineyards in the area and uses the de-suckering sprayer and Spotlight Plus on the other properties as well.

“I recommend Spotlight Plus because I’m getting such good results from it on my own grapevines.”

Spotlight Plus is also registered for use in tank mixes with knockdown herbicides to control a range of broadleaf weeds under vines and certain tree crops.

“We also use it through the boom spray with Basta herbicide as it will increase the speed of control and effectiveness on weeds such as marshmallow, wild radish, capeweed and Paterson’s curse.

Horticultural agronomist with Elders Griffith, Steve Hirst, said Spotlight Plus was widely used in the area to de-sucker vines and for general weed control.

“It is a quicker and more cost-effective option and, as it is a purpose-built low-drift formulation, it is very safe.”

He said Spotlight Plus is absorbed by green shoots but doesn’t move up or down in the plant so only controls the areas directly hit by the herbicide.

“It is a very good option on the market.”

Spotlight Plus is uniquely suitable for sucker control with its mode of action making it highly effective on treated areas and safe on unsprayed leaves.

It is absorbed by green leaves and stems and there is no translocation to the roots or to other areas of the plant, and no residual activity in the soil.

The active constituent in Spotlight Plus (carfentrazone-ethyl) is a unique herbicidal molecule that interacts with the plant’s photosynthetic system to form highly reactive compounds. These compounds rupture the plant cell membranes resulting in the cell contents leaking out which causes rapid cell death.

This mode of action relies on photosynthesis, so sunlight is essential for expression of the product’s herbicidal activity.

Spotlight Plus is registered for sucker control in grapevines, olives, tree fruits and tree nuts.

Spotlight Plus® is purpose built for effective management of unwanted suckers and weeds under vines, olives, tree fruits and tree nuts. Specially formulated for low drift and with an active ingredient that will not translocate, Spotlight Plus® provides effective control with a high degree of crop safety and major labour savings over hand pruning. For f urther inf orm ation, ple ase vis it f mccrop.com.au

Horticultural agronomist with Elders Griffith, Steve Hirst (left) and viticulturist and contractor Steven Barbon.

Advances in grapevine viral disease detection Use of optical imaging technology for virus surveillance in vineyards

By Vinay Pagay1 and Yeniu Mickey Wang1,2

INTRODUCTION

Grapevine viruses are widespread in nearly every major viticultural region globally and can have detrimental effects on vine productivity and grape and wine quality. The dominant viruses in Australian vineyards include the variants of Grapevine Leafroll-associated Virus and Grapevine Virus A. Virus transmission occurs between vines and vineyards via insect vectors and through infected propagation material. Management strategies such as roguing and replanting with certified, virusfree stock have shown to be effective in decreasing the incidence of viral diseases. New surveillance technologies to rapidly detect viral infections can aid traditional methodologies, e.g. tissue testing, for effective disease management in vineyards.

BACKGROUND

Of the more than 80 viruses that are known to infect grapevines worldwide, the Ampeloviruses grapevine leafroll-associated virus Types 1 and 3 (GLRaV-1, -3), which are associated with Grapevine Leafroll Disease (GLD), and the Vitivirus Grapevine virus A (GVA), which causes Shiraz Disease (SD), are amongst the most widespread grapevine viruses in Australian vineyards. Along with fungal pathogens, GLD is one of the most important diseases affecting grapevine cultivars and rootstocks worldwide (Maree et al. 2013) and has been reported to result in yield losses of up to 40% in Australian vineyards (Habili and Nutter 1997), costing between $300 and $2400 per hectare (Atallah et al. 2012). Grapevine Leafroll-associated virus Type 3 (GLRaV-3) is limited to the phloem in grapevines and shown to be transmitted by grafting as well as vectored by several species of soft scale (Hemiptera: Coccidae) and mealybug (Hemiptera: Pseudococcidae).

SYMPTOMOLOGY

Symptom expression resulting from viral diseases is complex and multifaceted, involving the virus, its host and the environmental conditions under which both exist. Variations in one or more of these factors will likely alter symptom expression. To complicate this further, variants of a virus can also alter the symptomology, e.g. GVA variants of Group II often produce symptoms while Groups I and III do not. Certain grapevine cultivars may also remain symptomless or have weak symptoms despite having a virus infection, e.g. white-berried grape cultivars. Viral disease symptoms can often mimic those resulting from abiotic stresses and nutrient deficiencies, making accurate detection challenging.

Shiraz Disease

Symptoms of Shiraz Disease (SD) can be apparent shortly after budburst. Budburst is often delayed and the young shoots are retarded in their development (Figure 1a). Preceding budburst, within the compound bud, primary bud necrosis (PBN) is often observed in Shiraz grapevines infected with SD. Progression of the symptoms as véraison approaches include changes in leaf colour from green to light green to pink and eventually to crimson (Figure 1b). Cane maturation and lignification is often delayed with green ‘islands’ evident in the cane internodes. Finally, the red leaves tend to exhibit delayed abscission and remain on the vine well into the dormant season. Shiraz Disease appears to be endemic to South Africa and Australia, and observed in several grapevine cultivars including Shiraz, Malbec and Merlot. There are also reports of symptomless Shiraz grapevines that tested positive for GVA (Wu et al. 2020).

IN BRIEF

■ Grapevine viral diseases such as Grapevine Leafroll Disease (GLD) and Shiraz Disease (SD) are detrimental to vine performance, crop yield and quality, vineyard sustainability and profitability.

■ Advances in portable optical sensors and computational modelling have enabled rapid disease detection of individual diseased vines.

■ Lab-based serological and molecular methods to detect viruses in plant tissues are reliable, but due to cost, limit the sampling density in vineyards.

■ Three methods of virus surveillance in vineyards are presented that enable rapid, widescale detection of viral diseases: airborne visible imagery, ground-based hyperspectral detection, and airborne hyperspectral imagery.

■ These methods are shown to be reliable in detecting GLD and SD in red and white-berried grape cultivars depending on phenological stage.

Leafroll Disease

Grapevine leafroll virus is present in all major viticultural regions globally and, associated with GLD, produces distinct symptoms starting around véraison.

Leaf margins begin to have a downward cupping tendency. While there is little to no colour change in leaves of white-berried cultivars, interveinal section of leaves of red-berried grape cultivars change colour from green to crimson or even purple with green veins. Leafroll symptoms tend to occur at distinct phenological stages and depend on cultivar. The effects of GLD on vine performance and fruit composition have been well-documented. These include delayed bud break, retarded shoot growth, decreased photosynthetic capacity of the leaves, delayed and uneven berry development (Figure 1d), sugar accumulation, reduced berry anthocyanin and polyphenol content, and reduced yield. In the most severe cases, vine mortality can result.

VIRAL DISEASE DETECTION

Traditional approaches

Traditional approaches of detection have included symptom-based detection (as described in the preceding section) and biological indexing in which an infected plant is grafted onto an indicator plant or grapevine cultivar (e.g. Cabernet Franc) and observed for the appearance of symptoms. In vitro biological indexing via imposition of an abiotic stress was recently shown to be useful for screening grapevine material (Cui 2015).

Current lab-based approaches to detect viruses include serological (enzyme-linked immunosorbent assay; ELISA) and molecular (real time polymerase chain reaction; RT-PCR) assays. Laboratory-based serological techniques such as enzyme-linked immunosorbent assay (ELISA) are widely used in diagnostic laboratories around the world for their simplicity, robustness, sensitivity, speed and virus specificity. This technique relies on the binding of the virus to its specific antibody. Despite its lower sensitivity to detect, especially low virus titres (concentrations in the tissue), it has been suggested that ELISA is more likely to detect most, if not all, of the genetic variants of a specific virus.

Molecular or nucleic acid-based techniques are widely used by diagnostic laboratories worldwide and are dominated by the ReverseTranscription Polymerase Chain Reaction (RT-PCR) procedure, although other similar methodologies exist including Loop-mediated Amplification of Mucleic Acid (LAMP). This test is highly sensitive and rapid, however, it requires trained labour and specialised equipment, has higher cost compared to ELISA, and cross-contamination risks are present.

Furthermore, specific genome sequence information is required for the development of primers to detect the virus. Therefore, any new or unknown virus will unlikely be detected using this technique. A single virus species can consist of many strains and new or divergent strains might be missed if they have genetic variability in the genome region used to design the PCR test.

More recently, virus detection can be done using high throughput genetic sequencing technologies, which is a non-specific molecular technique that can effectively sequence the genome of all organisms present in a sample without the need for their prior sequence information (as in the case of PCR). Therefore, this process allows for the detection of not only new viruses and their variants, but also the designing of molecular diagnostic tests that can be used for specific virus species or strain detection using PCR. Unfortunately, the high cost of nextgeneration sequencing makes it prohibitive for routine diagnosis and therefore is still predominantly a research tool.

Non-destructive approaches

Vineyard-based detection of viral diseases is highly desirable through widescale surveillance using mobile platforms such as ground-based vehicles (e.g. tractors, ATVs) and airborne systems (e.g. UAVs/drones or low-altitude aircraft). Using these platforms, high resolution imagery can be captured of individual grapevines to detect viral disease symptoms (described above). Such systems can be advantageous for routine monitoring of source blocks that supply propagation material to the industry (via nurseries). Advances in optical sensing technology such as visible (or red-green-blue; RGB) and multispectral cameras have aided

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Figure 1. Symptoms of grapevine virus A (GVA) showing delayed budburst and devigorated shoots in the foreground vs healthy vines in the background (a) and red leaf symptoms in the autumn (b); grapevine leafroll disease (GLD) showing red leaf symptoms post-veraison (c) and uneven berry development post-veraison (d).

the virus detection and surveillance effort in recent years. Since all optical technologies provide indirect detection methods, mathematical relationships (or models) need to be developed that relate the optical signal (i.e. reflectance of light at a specific wavelength) to the actual virus status of the vine determined via tissue testing and/or visual assessment. These models are typically developed using statistical methods or, more recently, machine learning methods.

Below are several case studies presenting the use of such optical sensor technology deployed on mobile platforms for the detection of SD and GLD.

Case Study 1: Airborne high resolution visible imagery for SD and GLD detection

Airborne RGB or visible imagery obtained from either unmanned aerial vehicles (UAVs; aka ‘drones’) or low altitude, manned, fixed wing aircraft have enabled the detection and surveillance of grapevine viral diseases in vineyards due to the high resolution of the camera systems that can detect disease symptoms. The RGB method using UAVs was used in a Riverland (South Australia) vineyard planted with Shiraz, many vines of which were infected with Shiraz Disease. The presence of the viruses was confirmed prior to the airborne detection using ELISA (for GVA and GLD). Test results were confirmed for SD using PCR at a commercial diagnostics laboratory. The UAV platform consisted of a DJI Mavic Pro 2 UAV equipped with a Hasselblad RGB camera (Figure 2a). From the high-resolution visible imagery collected at various phenological stages, single-vine level projected leaf area (PLA) was estimated. PLA is the total vine leaf area visible from overhead (as imaged by the UAV). A detailed description of the remote sensing platform, data acquisition and analysis procedure, and results can be found in Wang et al. (2023b).

Using PLA as a quantitative metric or indicator, we were able to detect Shiraz Disease, but not GLD (Figure 2b). Shiraz Disease-infected vines had lower PLAs, by as much as 70%, compared to healthy vines. The differences became apparent as early as 15 days post-budburst. From véraison onwards, this technique was not reliable as the PLA or canopy size differences decreased, in essence the SD-infected vines’ ‘caught up’ with the healthy vines. When the vines were infected by either GVA or GLRaV only

(i.e. not co-infected), the PLA was similar to healthy vines, therefore making them indistinguishable from uninfected vines and difficult to detect using the PLA technique. In this case, symptom-based detection could be utilised, particularly in red grape cultivars. Furthermore, this technique was found to be useful in distinguishing SD from grapevine trunk diseases (GTDs, e.g. Eutypa lata) based on the timing of symptom expression. By the véraison stage, GTD-infected vines almost always had devigorated shoots and lower PLAs compared to SD vines at the same stage. It should be noted that in this study GTDs were not specifically tested for using diagnostic methods, but solely symptomology.

Case Study 2: Ground-based (proximal) hyperspectral detection of SD

Ground-based techniques for detection of diseases offer advantages compared to the airborne methods including simplicity, speed, low cost and high resolution. Several sensor technologies exit for proximal (or near target, typically <2m) detection of grapevine viral diseases including RGB/visible cameras, and multispectral and hyperspectral radiometers or cameras. A handheld (proximal) spectroradiometer, i.e. a single point hyperspectral sensor (Figure 3), was utilised in an Adelaide Hills vineyard planted with Chardonnay and Pinor Noir grapevines,

both co-infected with GVA and GLRaV-1 (i.e. SD-positive) as confirmed with lab-based tissue testing using ELISA. The ‘healthy’ vines in both blocks were uninfected with either virus and were also negative for GLRaV-3 and GLRaV-4. Data analysis involved statistical modelling using partial least square discriminant analysis that was used to predict the disease status of the vine (healthy vs infected). Detailed methodology and results can be found in Wang et al. (2023a).

Diseased Chardonnay vines appeared to increase their leaf reflectance over time as the season progressed, with a similar trend observed in Shiraz up to véraison when the leaves began changing colour to red due to anthocyanin accumulation. The visible spectrum and, in some cases, rededge spectrum were found to be useful for the detection of SD. Prediction accuracy for Chardonnay at véraison was around 67%, increasing to 74% shortly before harvest. For Pinot Noir, model accuracy was around 88% at véraison, increasing to 95% by pre-harvest (data not shown). The models developed in this study were found to be useful in predicting disease status at the same phenological stage as when the data for the model was collected and, in some cases, offer forward predictions by one to two months.

Case Study 3: Airborne hyperspectral detection of SD

Multispectral and hyperspectral sensors capture several to potentially thousands of

Figure 2. (a) UAV platform for high resolution visible remote sensing of grapevine viruses; (b) Projected leaf area of Shiraz grapevines in Barossa (left) and Riverland (right).

Figure 3. Spectroradiometer for proximal sensing of grapevine viruses.

bands or wavelengths of light, respectively, across the visible, near infrared and short-wave infrared spectra. The ability to detect across a range of wavelengths provides information beyond that possible with human vision and which are influenced by viral diseases amongst other stresses. Unlike proximal hyperspectral sensing, remote sensing offers unparalleled advantages including coverage, permitting virus surveillance at scale, speed and flexibility, albeit at a higher cost and complexity of data analysis. A recent study using this technique in SD-infected vineyards in the Riverland, Barossa and Adelaide Hills was completed using a UAV-equipped hyperspectral imager covering the visible and near infrared range of wavelengths (Figure 4a). Partial Least Square Discriminant Analysis regression modelling was used to classify individual pixel and vines as either ‘infected’ or ‘healthy’.

Results of this study showed that virus detection using remote sensing was reliable during the véraison and especially pre-harvest phenological stages, with accuracies as high as 74%, 85%, 83% and 81% for Chardonnay (harvest), Pinot Noir (harvest), Shiraz (véraison) and Cabernet Sauvignon (harvest), respectively (Figure 4b). For a given cultivar, model accuracies varied only slightly based on region. For Chardonnay, Pinot Noir and Cabernet Sauvignon, the models could also predict the virus status in subsequent seasons with accuracies of 58%, 61% and 91%, respectively. When the model of a specific cultivar was used across regions, i.e. model built from one region was used to predict the virus status of the same cultivar in a different region under different climatic conditions (e.g. Adelaide Hills vs Barossa or Riverland), GLD and SD were well-predicted in Cabernet Sauvignon and Shiraz with accuracies of 85% and 88%, respectively. Based on these results, it is evident that UAV-based hyperspectral remote sensing is a promising method to detect grapevine viruses at specific phenological stages.

CONCLUSIONS

Advances in optical sensor technology, particularly those that can be used on mobile platforms, have enabled large spatial-scale virus surveillance of vineyards for the purposes of disease detection. With spatial maps of disease incidence at the vine level, practitioners and vine health inspectors can not only obtain the disease status and severity of their blocks, but also target leaf sampling for disease testing using traditional lab-based methods. A recent cost comparison of using various approaches of virus detection in vineyards

found that lab-based methods of virus testing, despite being the ‘gold standards’, were also the most expensive (Wang et al. 2022). High resolution airborne visible imagery was the least expensive of all the methods assessed, closely followed by ground-based visual assessments (based on symptomology), the latter requiring training of inspectors and relying on symptom expression, which is usually muted in white grape cultivars. Future developments in viral disease detection will undoubtedly involve rapid and more sophisticated platforms (e.g. satellites) and data acquisition tools (e.g. LiDAR). With an increase in computational power and data communication speed, generation and visualisation of near real time maps of vineyard disease status may be feasible in the future.

ACKNOWLEDGEMENTS

The authors would like to thank the South Australian Wine Industry Association, Riverland Wine, and Wine Australia for supporting this work.

REFERENCES

Atallah, S. S.; Gomez, M. I.; Fuchs, M. F. and Martinson, T.E. (2012) Economic impact of grapevine leafroll disease on Vitis vinifera cv. Cabernet Franc in Finger Lakes vineyards of New York. American Journal of Enology and Viticulture 63(1):73-79.

Cui, Z.H.; Bi, W.L.; Pan, C.; Xu, Y. and Wang, Q.C. (2015) Abiotic stress improves

Figure 4. (a) UAV equipped with a hyperspectral camera for high resolution remote sensing of grapevine viruses; (b). Model prediction results (accuracy) for virus detection across three South Australian viticultural regions. Figure adapted from Wang et al. (in review).

in vitro biological indexing of Grapevine leafroll-associated virus-3 in red grapevine cultivars. Australian Journal of Grape and Wine Research 21(3):490-495.

Habili, N. and Nutter, F.W. (1997) Temporal and spatial analysis of grapevine leafrollassociated virus 3 in Pinot Noir grapevines in Australia. Plant Disease 81(6):625-628.

Wang, Y.M.; Ostendorf, B.; Gautam, D.; Habili, N. and Pagay, V. (2022) Plant viral disease detection: From molecular diagnosis to optical sensing technology - A multidisciplinary review. Remote Sensing 14(7):1542.

Wang, Y.M.; Ostendorf, B. and Pagay, V. (2023a) Evaluating the potential of highresolution visible remote sensing to detect Shiraz Disease in grapevines. Australian Journal of Grape and Wine Research, Special Issue: 18th Australian Wine Industry Technical Conference.

Wang, Y.M.; Ostendorf, B. and Pagay, V. (2023b) Detecting grapevine virus infections in red and white winegrape canopies using proximal hyperspectral sensing. Sensors 23(5):2851.

Wang, Y.M.; Ostendorf, B. and Pagay, V. Seeing the unseen: Detecting plant viral diseases using high-resolution hyperspectral imagery. [in review]

Wu, Q.; Habili, N.; Constable, F.; Al Rwahnih, M.; Goszczynski, D. E.; Wang, Y. N. and Pagay, V. (2020) Virus pathogens in Australian vineyards with an emphasis on Shiraz Disease. Viruses 12(8):818. WVJ

Managing botrytis sustainably Investigations of dsRNA silencing technology

By Tory Clarke and Professor Kathy Evans, Tasmanian Institute of Agriculture, University of Tasmania, Sandy Bay Campus, Hobart, Tasmania

The Tasmanian Institute of Agriculture, at the University of Tasmania, is leading the development of an RNA-based botryticide for winegrapes. As part of the Australian Research Council (ARC) Research Hub for Sustainable Crop Protection, our team (Dr Tory Clarke, Professor Kathy Evans and PhD Candidate Akeem Taiwo) is exploring the potential of an innovative product called BioClay™, which has the potential to revolutionise the wine industry by offering a sustainable and biodegradable alternative to chemical fungicides against botrytis bunch rot (BBR).

BBR poses significant challenges for grapegrowers, leading to considerable yield losses and costly issues during winemaking despite current management practices. We estimate that the processed value of winegrapes in Tasmania alone could be up to 24% higher if costs due to botrytis disease are recuperated. Good viticultural practices can counter some of the environmental triggers for BRR development, however a well-timed crop protectant can make the difference between a winemaker accepting or rejecting crop for a particular wine style. With limited options and the constant threat of fungicide resistance, a new, effective and sustainable crop protectant will be a welcome addition to the crop protection toolbox.

BioClay was developed from pioneering research conducted by Professor Neena Mitter and Professor Gordon Xu at the University of Queensland. This biodegradable spray solution consists of clay particles that stabilise doublestranded RNA (dsRNA) and gradually release it, working harmoniously with grapevines’ natural defence mechanisms to supress diseases like BBR through RNA silencing. The clay particles on the leaf surface slowly degrade in the presence of natural carbon dioxide and moisture, leaving no residue or toxins. The dsRNA silencing technology is highly targeted and specific to the causal fungus, Botrytis cinerea, providing a more environmentallyfriendly approach to crop protection.

Our research marks the world’s first testing of BioClay technology for suppressing BBR in winegrapes. To address this opportunity, we are meticulously testing the dsRNA BioClay product in a series of in vitro and controlled environment trials to establish its efficacy relative to existing commercial solutions, and to better understand its mechanisms of actions. Our current research is focusing on

optimal application methods, concentrations and timings during grapevine development. It also draws upon our understanding of factors promoting the colonisation of grape flowers and berries by the fungal pathogen.

Experimentation with BioClay requires a steady supply of grapevines that flower and produce berries year-round, enabling us to conduct comprehensive studies across the lifecycle of the fungus. Using commercial cuttings, we propagate vines under controlled temperature and light conditions to induce inflorescence development. We have established a reproducible propagation system to quantify the susceptibility of grapevine inflorescences to botrytis colonisation, and understand how BioClay can be optimised to supress the botrytis pathogen during berry development.

We are also investigating the mechanisms by which dsRNA (the botrytis-supressing component of the product) can move from the site of application into the developing inflorescence, to maximise protection performance against latent botrytis colonisation across inflorescence and berry development. We presented early results of our work at the International Congress of Plant Pathology in Lyon, France, in August 2023.

As lead researchers on this project, we are excited about the prospect of paving the way for a potential product that can be utilised by winegrowers to sustainably manage BBR in vineyards across Australia, and globally. By providing an environmentally-friendly, biodegradable and highly effective solution, BioClay has the potential to transform vineyard practices worldwide, benefiting grapegrowers and promoting a more sustainable future for the wine industry.

The project is part of the ARC Research Hub for Sustainable Crop Protection and funded by the Australian Government. The Australian Wine Research Institute and the South Australian Research and Development Institute are also contributing to the winegrape research led from Tasmania.

Dr Tory Clarke (pictured) and her University of Tasmania colleagues Professor Kathy Evans and PhD Candidate Akeem Taiwo are testing BioClay technology for its ability to supress botrytis. The research is the first undertaken in the world to investigate BioClay technology for suppressing botrytis in winegrapes.

Frost — causes and mitigation strategies for established vineyards

By Tony Hoare

Scientists say extreme weather events, such as heatwaves, fires and floods, are likely to become more frequent and intense due to climate change. In this first of a series of articles on managing extreme weather events, Tony focuses on frost.

The damage caused by frost events can be devastating for vineyards. One night of frost in late spring or early summer can wreck an entire season. Many winegrowing regions around the world are experiencing frost events more consistently and over a longer time period compared with previous seasons. In southern Australia, where the majority of winegrapes are grown, this is largely due to an increase in the duration of the ‘frost season’ by 26 days, with the last frost occurring an average of four weeks later compared with the 1960-1990 long-term mean (Crimp et al. 2016). The added effect of changing weather cycles from La Niña to ENSO-neutral to El Niño greatly influence the likelihood of frost events with the predicted current weather patterns.

EL NIÑO AND FROST

The World Meteorological Organisation recently predicted an 80% chance of moving into El Niño in July to September 2023. In the past during El Niño weather cycles, regions in southern New South Wales and northern Victoria have experienced 15-30% more frost days which has been attributed to decreased cloud cover leading to cooler-than-average night time temperatures (BOM website). Less cloud cover due to the drier El Niño weather cycle, together with clear, still nights (low or no wind), greatly increases the risk of frost damage occurring in many Australian vineyards. Weather conditions during El Niño cause the loss of the protective thermal heat radiation from soil which escapes into space more readily and allows a ‘radiation frost’ to form in the subsequent cooler temperatures.

In addition to contributing to a greater chance of occurrence and a longer frost risk period, El Niño weather events also contribute to increased frost risk damage to vines by causing warmer-than-average

daytime temperatures in spring and summer. You might think this would have the opposite effect, however, the warmer conditions cause earlier vine phenology and, in particular, earlier budburst. Earlier budburst and the emergence of green tissue greatly increases the susceptibility of vines to frost damage. Early season bud damage from frost is increased by 80% for green tip and beyond compared with woolly bud growth stages (Poni 2023).

The trend towards longer ‘frost seasons’ poses some challenges for winegrape growers and fortunately there are a number of vineyard management strategies and hardware available to assist growers combat the effects of frost. With the increased risk of frost events occurring due to the impending El Niño weather cycle, what are the options to protect your vineyard from damage?

grape variety, rootstock, cordon height, soil type and midrow and undervine management as well as the timing of pruning. The location of a vineyard has a significant influence on frost risk with the general rule of thumb being the further inland a vineyard is from the coast the greater the risk of frost occurring. The overall selection criteria for locating a vineyard site is complex and the risk of frost is only one of many factors usually considered when choosing a site. Historical climate averages and tools such as the Spring Frost Index (SFI) (Gladstones 2004) do provide a broad understanding of frost risk occurrence within a region. However, the value of this information is constantly being challenged by a more uncertain and extreme climate such as the severe frost events that French wine regions experienced in 2021 and 2022 (https://www.foodandwine.com/news/ france-vineyards-late-frost-spring-2022).

PREPARING A VINEYARD FOR FROST

VINEYARD FACTORS INFLUENCING FROST

The climate factors associated with frost events are well known. However, understanding the vineyard factors that may be contributing to frost damage is the best place to begin when considering how to minimise impacts from frost damage. The most commonly-occurring frosts in Australia are radiation frosts which aren’t as severe as advection frosts for which there is really no chance of overcoming damage.

Apart from climate conditions for frost, the main risk factors influencing frost damage in a vineyard are the location, topography, aspect,

Unfortunately, there is little that can be done to prepare a vineyard for an advective frost when cold, dry air migrates to a site (Loader 1978). Thankfully, this type of frost is less common in Australian winegrowing regions than radiation frosts which occur when the thermal heat accumulated and stored in the soil during the day isn’t adequate to counter the radiative heat loss to the sky on clear still nights (Trought et al. 1999). Combatting the effects of radiative frosts relies on prolonging the thermal heat in soils for the duration of a frost weather event to counteract the cold temperature leading to frost damage.

The first step to managing frost is to identify the most vulnerable areas for frost damage and where temperature variations are located. Areas prone to frost are also called ‘frost pockets’ as they can be in isolated areas within a property depending on topography. Frost is influenced by topography where cold air moves downhill and settles in lower areas. If this cold air cannot flow away from a vineyard due to a barrier, such as vegetation, windbreaks or other physical structures such as buildings, then the risk of frost is increased. Flat land

more

is

A frost event in the Adelaide Hills in 2018.

Photo: Kym Anderson

susceptible to frost than sloping topography due to a lack of natural air drainage which occurs more readily on a gradient. Aspect can influence frost risk as well, mainly through the timing of sunrise that warms air and soil and the length of soil warming by the sun during the day. Slopes can also offer protection from cold southerly and westerly winds associated with advective frosts (Young 2007). The proximity of land to surface bodies of water also has an influence on frost with water acting as a thermal source of heat that combats frost by warming cold air through convection, leading to increased air movement and protection.

Technology has been adapted by George Dridhan from McLaren Vale-based Integrated Precision Viticulture (www.ipvit.com.au) which uses a thermal, pan tilt camera to map in near, real time hot and cold stress in a vineyard. The camera uses a thermal sensor and RGB (red, green and blue) colour reference to map areas of variation across a site. The camera can be used to work out the best location for fixed or mobile frost fans or to implement other frost risk management strategies.

wine regions was “never cultivate before the Melbourne Cup [first Tuesday in November]”, although this might need to be reviewed given current weather patterns.

Undervine mulches and midrow vegetation cover also prevent the warming of soil and, therefore, are not recommended for highrisk frost vineyards. If vegetation is required to be grown in the midrow then it should be cut down and kept short to assist with frost control. Increased levels of soil moisture, particularly in the top 30cm of soil, also allow for more effective warming of soil and assists in improving the accumulation, storage and release of heat as a thermal barrier to frost. The cost benefit of using irrigation as a frost control strategy needs to be analysed as well its effects on weed growth and vineyard accessibility when compared to other frost management strategies.

CORDON HEIGHT

Temperatures are lowest at the soil surface and increase as you move upwards in a steep gradient. The frost risk decreases as cordon height increases. The variation in temperature between 0.9m and 1.4m was found to be as much as 0.5°C (McCarthy et al 1992). Lifting a low and frost-prone cordon height can be done when reworking a permanent cordon or whilst training newly field-grafted vines. There is no ideal recommended cordon height and it varies according to many factors of consideration for vineyard management other than frost control.

MONITORING FOR FROST

Table 1. Freeze sensitivity and cold damage vine growth stages.

Stage of development Critical tissue temperature at which damage is observed (°C) in Pinot noir

50% tissue death No damage

Dormant enlarged -14.0

Green swollen -3.4

Shoot burst -22 -1.0

First leaf -2.0 -1.0

Second leaf -1.7 -1.0

Fourth leaf -1.2 -0.6

VINE FACTORS INFLUENCING FROST

The stage of a vine’s phenological growth greatly affects its susceptibility to cold conditions. This is primarily due to the increased water content of the vegetative parts as the vine grows which become more prone to frost from frozen water in plant tissue which damages cells. The more advanced the growth stage of a vine, the greater the freeze sensitivity at which tissue damage occurs from cold conditions (Table 1, Gardea 1987). Selection of a grape variety that has a later budburst is a good strategy when planting or reworking a vineyard in a frost-prone area. Rootstocks can also delay budburst (Menora et al. 2015).

SOIL MANAGEMENT AND FROST

How the soil surface is managed in frost risk areas can have a huge effect on the thermal protection of crops offered by soil. The soil acts as a heat sink and radiates heat captured during the day into the air above to keep canopies warm enough above freezing point. Different soil types have different soil thermal qualities with dark heavy soils having a greater ability to harness, store and release radiative heat at night than lighter coloured soils with sandy textures.

Compact, undisturbed soils with low or no vegetation provide the best thermal protection against frost compared with cultivated or vegetation covered soil in vineyards. Cultivation reduces the ability of soil to combat frost as it opens soil to air and large air spaces are less able to store heat. Whilst this type of soil management strategy has many other negative effects for viticulture, it is definitely the most effective soil management approach for frost mitigation. An old saying around inland

Having a lead time before frost occurs is critical when using active frost control responses. Weather forecasts from the Bureau of Meteorology and nightly news weather services generally include regional frost alerts. Most modern weather stations allow parameters for frost risk to be programmed and an alarm set.

In general, weather conducive to frost is a sequence of events beginning with the passage of a weak cold front, followed by cold southerly winds and the establishment of a ridge of high pressure. Another general rule of thumb for frost weather conditions is a 1°C temperature decline per hour after sunset if relative humidity (RH) is moderate to high (Loader 2008). Some other useful technology for frost control, particularly by water emitters, is the frost watch cellular frost alarm (https://welnz.com/ product/frostwatch-cellular/?v=6cc98ba2045f).

If helicopters are required for frost control the smart light warning light is useful for pinpointing areas requiring attention for frost control from the air (https://welnz.com/product/ smartlite/?v=6cc98ba2045f).

LATE WINTER PRUNING (LWP)

One way to delay budburst by up to eight weeks (Friend et al. 2007, Zheng et al. 2017, Allegro et al. 2020) is the practice of late winter pruning. This technique was developed using the grapevine physiological principle of acrotony where distal buds (higher ends of canes) burst before proximal (lower positions) buds. This works well for spur-pruned vines where normal mechanical pre-pruning can occur to leave taller spurs of four to five buds. Once budburst occurs on the higher buds, the vines are then pruned back to two-bud spurs which remain dormant.

LWP can also be used for cane-pruned vines in a two-step process where canes are

A bare earth strategy — effective soil management for frost mitigation in a high risk frost location. Photo Nigel Bleishke 2023.

Vine pruned during winter dormancy (left); vine pruned with LWP technique (right), McLaren Vale. Photo: Author

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pruned as long as possible and left in the vertical position. Following budburst, canes are shortened, replacement spurs pruned to two buds and canes wrapped down onto the cordon wire (Poni 2023). The technique has worked well in Australia for Shiraz with no effect on yield (Moran et al. 2018), however, some yield loss can be a side effect of LWP (Petrie at al. 2017) and some differences have been observed between TSS, TA, pH, phenols and anthocyanins when compared with conventionally-pruned control vines.

FROST FANS – PERMANENT, PORTABLE AND AERIAL

Permanent frost fans are a considerable financial investment that only do one thing. It’s imperative that financial modelling is done before investing in this infrastructure (Snyder et al. 2005). Frost fans, both permanent and portable, provide a reliable and fully automated frost control option, however, they rely on certain conditions to be fully effective. Relying on warmer air to work effectively, they can be ineffective under weak atmospheric inversion conditions (Yongguang et al. 2015). In general, fans increase the temperature between the top of a fan tower and the fruiting wire by about 50%. In the event of a severe cold the overall temperature with fans may still remain cold enough to cause damage (Jones 2010). Depending on the value of the crop, frost fans can, however, pay for themselves by saving only one crop from frost damage.

Portable frost fans can be very useful for ‘frost pockets’ or smaller areas of high frost risk. They provide the flexibility to move between different varieties depending on phenology and can also be used for cooling vineyards in heatwaves through misting attachments.

OVERHEAD SPRINKLERS

The application of water with specificallydesigned overhead sprinklers (flippers) to target vines can be an effective frost mitigation tool. Usually, these emitters will be installed on trellis posts at the time of planting the vineyard, however, they can be retrofitted. The principle on which they work against frost damage is that water from the emitters releases heat when it freezes. When ice contacts the surface water it will remain at a temperature of around 0°C which is less damaging to vine tissue.

Frost control emitters have been found to be effective to around -5°C, or lower for some systems. For effective frost control the application rate is critical and, therefore, the system needs to have adequate water

resources available, an effective pumping system and be cost effective when considering the costs of power and water.

Checklist for using water for frost control

• Water resource – water supply to provide the volume required. Cost/benefit.

• Pump system – has the capacity and efficiency to deliver water when required

• Emitters – have the ability to deliver water as effective control over the area required in an effective timeframe

• Climate monitoring – critical temperature, humidity, wind indices of frost

• Vine growth stage – phenological growth stage; damage susceptibility.

The downside to using water for frost control is the volume required which, depending on the frost pressure, can be a very high percentage of a water allocation. Keeping in mind the increased requirement of water resources for irrigation during El Niño, other frost control may be more economical.

OTHER CONTROLS — OLD AND NEW

Although still widely used in Europe, the use of oil-burning ‘smudge pots’ was banned in California in 2019 due to their negative environmental effects and risks to human health. They are not a common or recommended frost control tool in Australian vineyards.

Canopy sprays for frost protection of crops is an ongoing area of research. Much of the current research is focussed on lowering the effect of ice nucleating bacteria which exacerbate frost by using biostimulants such as strains of Pseudomonas syringa. Whilst they present a promising strategy, they are not yet proven in commercial vineyards.

Physical barriers to cover vines such as geofabrics and even blankets have been used successfully to prevent frost damage on a small scale although the cost benefit does not translate on a more commercial scale. Current research into shade cloths, bird netting and hail protection fabrics may also offer frost protection in permanently covered vineyards in the future.

REFERENCES AND FURTHER READING

Allegro, G.; Pastore, C.; Valentini, G. and Filippetti, I. (2020) Post-budburst hand finishing of winter spur pruning can delay technological ripening without altering phenolic maturity of Merlot berries. Australian Journal of Grape and Wine Research Volume 26(2):139-147

Friend, A.P.; Trought, M.C.T.; Stushnoff, C. and Wells, G.H. (2011) Effect of delaying budburst on shoot development and yield of Vitis vinifera L. Chardonnay ‘Mendoza’ after a spring

freeze event. Australian Journal of Grape and Wine Research 17(3):378-382.

Gardea, A.A. (1987) Freeze damage of Pinot Noir (Vitis vinifera L.) as affected by bud development, INA-bacteria, and a bacterial inhibitor. Masters Thesis, Oregon State University.

Gladstones, J. (1993) Viticulture and the Environment. Winetitles, Underdale, South Australia.

Gladstones, J. (2011) Wine, Terroir and Climate Change. Wakefield Press, Kent Town, South Australia. p24.

Jones, J. and Wilson, S. (2010) Arming against frost. Wine Australia Factsheet. Online; https://www. wineaustralia.com/getmedia/6740ada2-1be7-4e3eb002-d5f35ae52ba7/201009-Arming-against-frost.pdf

Loder, H. (2008) Frost Protection in Viticulture: A Users Guide for South East Irrigators, Wingara Wine Group Pty. Ltd. Online https://coonawarra.org/ wp-content/uploads/2017/04/Frost-Protection-inViticulture-A-Users-Guide-for-South-East-Irrigators-H. Loder-2008.pdf.

Loder, M. (1978) Frost Protection of Horticultural Crops by Sprinkler Irrigation. CSU VIT2013 Course Notes p58-65.

McCarthy, M.J.; Dry, P.R.; Hayes, P.F. and Davidson, D. (1992) Soil management and frost control. Viticulture. Volume 1. Winetitles, Underdale South Australia.

Menora, N.D.; Joshi. V.; Kumar, V.; Vijaya,D.; Kanti Debnath, M.; Pattanashetty, S.; Padmavathamma, A.S.; Variath, M.T.; Biradar, S. and Khadakabhavi, S. (2015) Influence of rootstock on bud break, period of anthesis, fruit set, fruit ripening, heat unit requirement and berry yield of commercial grape varieties. International Journal of Plant Breeding and Genetics 9(3):126-135.

Pomranz, M. (2022) Late-April frosts in 2021 produced one of the worst harvests for the French wine industry. Food and Wine Online, France. Published on 5 April. https://www.foodandwine.com/ news/france-vineyards-late-frost-spring-2022

Poni, S. (2023) Designing and Managing a Sustainable Vineyard in a Climate Change Scenario, pp71-81. Independently published.

Snyder, R.L.; De Melo-Abreu, J.P. and Mattulich, S. (2005) Frost protection fundamentals, practice and economics Volume 2. Food and Agriculture Organisation (FAO) of the United Nations. Rome 2005. https://www.repository.utl.pt/ bitstream/10400.5/4728/1/REP-FROST_Volume2.pdf

Trought, M.; Howell, G.S. and Cherry, N. (1999) Practical considerations for reducing frost risk in vineyards. Report to New Zealand Winegrowers. World Meteorological Organization (WMO) WMO Update: Prepare for El Niño https://public.wmo.int/ en/media/press-release/wmo-update-prepare-elni%C3%B1o

Yongguang, H.; Wenye, W.; De Melo-Abreu, J.P.; Shapland, T.M.; Hong, Z. and Snyder, R. (2015) Comparative experiments and effectiveness evaluation on vertical blowing fans (VBF) for frost protection. International Journal of Agriculture and Biological Engineering 8(5):36-42.

Tony is an independent viticulturist based in McLaren Vale, South Australia. He has held many roles in viticulture over a 30-year career. He operates a vineyard advisory and field grafting service, Hoare Consulting, and shares with wife Briony a wine label and wine tourism venue, Beach Road Wines, in McLaren Vale. He can be followed on LinkedIn. WVJ

Future success in wine industry growth and sustainability relies on improved plant material

By Peter Cousins, E. & J. Gallo Winery,

600 Yosemite Blvd, Modesto, California, United States of America.

Email: peter.cousins@ejgallo.com

Dr Peter Cousins is a grape breeder at E. & J. Gallo Winery where the grapevine improvement program he leads focuses on the breeding, introduction and evaluation of proprietary winegrape varieties and selections with enhanced quality. Before joining E. & J. Gallo Winery, Peter was a grape rootstock breeder and geneticist with the United States Department of Agriculture’s Agricultural Research Service, based in Geneva, New York. At the Australian Wine Industry Technical Conference held in July 2022, Peter delivered a presentation titled ‘Grapevine varieties for the future’. The following article reflects the meaning, if not the precise verbatim words, of that presentation in which he shared his thoughts on developments in winegrape breeding.

INTRODUCTION

Wine composition and grape yield and quality are strongly influenced by grapevine planting material, including cultivar (fruiting cultivar or scion) and clone (selection). Technology vectors, business initiatives and evolving consumer demand create opportunities and drive responses in winegrape planting material improvement, innovation and adoption. When we recognise the forces that drive change in planting material, growers, winemakers and researchers in the public and private sectors are better positioned to direct those forces.

VINEYARD AND CULTIVAR LIFETIMES

Vineyard lifetimes are expected to decrease, which increases both the need for new plantings and the opportunity for introducing new plant material. Although a few vineyards are productive for one century or longer, intensively-farmed, irrigated winegrape vineyards are rarely commercially maintained for much longer than 30 years before replanting.

Losses due to fungal trunk diseases and virus diseases and the desire to benefit from the implementation of improved mechanisation, yield and quality through a new trellis are the main limitations for vineyard productive life. Recent outbreaks of newly important virus diseases, such as red blotch in California, and more vectored spread of the viruses associated

with other serious virus diseases, such as leafroll, reduce average vineyard productive lifespan.

Economic models aid growers in determining when to remove less profitable vineyards, although these economic models tend to encourage more rapid replanting. Although prophylactic post-pruning wound treatment is shown to be effective in reducing trunk disease, the trend towards mechanised pruning to spurs and away from hand labourintensive cane pruning, suggests that trunk disease will be increasingly important in limiting vineyard productive life (since spur-pruned vineyards tend to have more susceptible pruning wound area per vine than do canepruned vines, therefore spur-pruned vines tend to have shorter productive life than canepruned vines).

Winegrape cultivar specifications and utilisation are narrowing, paralleling the same trend in other crops and in animal husbandry. In the past there was a much greater need for and tolerance of generalist cultivars — those grapes that were used broadly in many different products. For example, Muscat of Alexandria was used as a winegrape, a table grape, and for dried fruit production. Although the intrinsic varietal attributes of Muscat of Alexandria haven’t changed over time, the expectations of the market for dried grape cultivars and table grape cultivars have changed a lot and Muscat of Alexandria now

has a very minor presence only in table grape and dried grape production, though it is still very competitive as a winegrape and currently being planted as a winegrape. Improved grape cultivars of the future will magnify this bifurcating trend — dried grape and table grape cultivars will be more and more specialised and less overlapping than they are now (both cultivar categories very strongly dominated by seedless types) and winegrape cultivars will be dedicated to wine production and almost never will be packed as a table grape for fresh consumption or dried.

Short lots (insufficient quantities of grapes for their intended use, such as the first harvest in a table grape vineyard which ordinarily does not receive sizing treatment), packing house culls, and other non-target grape sources will still be vinified and these represent the interest in utilising the fruit to its most profitable use, even if not the primary use for which it was intended.

With increased specialisation of cultivars, grapes of a particular cultivar are better suited to their end use as wine and thus more valuable. However, there is inherently less flexibility in specialisation, so when market demand changes, more specialised cultivars are likely to become obsolete and, thus, will be removed more rapidly than more generalised cultivars, even though the more specialised cultivars at their peak demand are more valuable.

MANAGEMENT PRACTICES INTERACT WITH PLANT MATERIAL

New trellising and training systems in table grape and dried grape production have enabled important yield and quality increases. However, trellising and training innovation in these sectors has peaked. For dried grape production in particular, the adoption of improved trellising and training methods has allowed for a strong trend towards mechanisation and away from hand labour in harvesting. Observing that trellising and training innovation has peaked does not mean that new ideas have ceased, only that the pace of innovation is diminishing. Winegrape trellising and training innovation has fallen behind other grape categories with the consequence that winegrape trellising and training innovation still has the opportunity to grow, with many important improvements likely to come from concepts that are now well-known and widespread in table grape production, such as divided overhead canopies.

Winegrape plant material improvement will support and interact with mechanisation trends, such as greater adoption of mechanical harvesting, whole cluster mechanical harvesting, berry and cluster sorting, and compositional uniformity. For example, cultivars and selections with loose clusters and long peduncles tend to harvest with less juicing than cultivars and selections with compact or tight clusters and short peduncles. Mechanical harvesting favours cultivars with uniform ripening, as differential harvest among the clusters of a single vine is difficult with current machinery. In contrast to the continuing need

for improved winegrape cultivars and selections to match innovation in winegrape trellising and training, dried grape cultivar improvement is nearly complete and table grape cultivar improvement is awaiting the co-development of routine mechanical harvest methods.

SELECTIONS

Grapevine cultivars are clonally or vegetatively propagated. Lineages within cultivars may be identified and separately propagated. These lineages are known as clones or selections. Here ‘selection(s)’ means a lineage within a cultivar rather than the designation of plant material at an intermediate stage of breeding that is more elite than an unevaluated seedling and less elite than a new commercially introduced cultivar. The use of the word ‘clone’ in viticulture can be confusing outside the discipline because grapevine cultivars themselves are clonally propagated and, thus, each grapevine cultivar in a horticultural sense is a clone. Here I will use ‘selection’ to refer to lineages within cultivars, which is closer to the way that other horticultural crops describe vegetatively propagated lineages within cultivars.

Selections are created and maintained by recording, tracking and discriminating the source of propagation material. Are there differences in vine phenotype and/or wine composition among selections of a cultivar? There could be, but these differences do not inherently define selections.

For the purposes of viticulture and oenology, however, it is the observed and repeatable differences among selections

that are important. Two selections that are distinct because of their origin, yet are indistinguishable in yield and grape and wine composition, have little to materially contribute.

The chief drivers of differences in vine phenotype and/or wine composition among selections are differences in phytosanitary status and/or genetics. Infection by viruses, bacteria and fungi can cause differences in vine phenotype and/or wine composition. For example, some viruses are associated with leafroll disease which has symptoms in black-fruited cultivars of lower fruit colour and soluble solids and a rolled-leaf phenotype. Selection differences due to virus infection differences are very widespread in viticulture.

Genetic difference is another cause of variation in vine phenotype and grape and wine composition among clones. For example, Chardonnay is ordinarily a seeded, whitefruited cultivar producing grapes with relatively low monoterpene fruit content. However, there are selections of Chardonnay that are seedless, red-fruited or with high monoterpene content, respectively, and these differences are due to differences in DNA sequence genetics between the selections with special fruit characters and the selections with typical fruit. Genetic differences underlie the variation shown in fruit colour among Pinot Noir/Pinot Gris/Pinot Blanc, Grenache Noir/Grenache Gris/Grenache Noir, and Cabernet Sauvignon/ Malian/Shalistin. In some cases, the underlying genetic differences, such as single nucleotide variation, are known (Battilana et al. 2011).

Although the current situation is that selection differences are driven both by phytosanitary and genetic causes, we expect that in the future, genetic causes will be the primary and intentional driver. Genetic causes are more stable than phytosanitary causes. Phytosanitary causes for differences among selections overwhelmingly are negative, with selections showing symptoms of virus disease, having inferior yield and fruit composition when compared to selections that are symptom free and test negative for viruses.

Some have suggested that infection with certain viruses may have a salutary effect, perhaps due to reduced crop load or to a longer ripening period. However, the same effects may be achieved with viticulture management practices without incurring the yield or compositional losses due to virus infection.

The methods for detecting pathogen infection of grapevines are becoming more sensitive and faster. Nucleic acid, immunological and woody indexing approaches are in routine widespread use. More testing

provides more granular information about the phytosanitary status, which aids nursery operators and growers in reducing plantings of infected vines and slowing pathogen distribution and spread. The development of plant material that tests free from pathogen infection uses micropropagation or, less commonly, thermal therapy or cryotherapy. Candidate vines propagated following therapy approaches are tested for pathogen infection. Until virus-resistant cultivars are widespread, virus management in plant material will

Innovation in winegrape plant material is improving in speed and accuracy due to better evaluation and validation methods. For example, refinements to microvinification practices have enabled the production of small batches of wine from experimental cultivars and selections that closely predict the attributes of wine expected from commercial-scale fermentations.

come through the planting of vines that were themselves tested or propagated from virus tested foundation or mother vines.

NEW WINEGRAPE CULTIVARS

Winegrape breeding for the introduction and commercialisation of new cultivars uses crossing and hybridisation among cultivars and other germplasm parents. This approach is used widely to create new winegrape cultivars with special fruit and wine composition, disease resistance, environmental adaptation, and other useful traits.

Crossing is the practice of breeding in which both parents belong to the same species while hybridisation is the practice of breeding in which the parents belong to different species. For example, Taminga was developed by crossing because both parents belong to the Vitis vinifera species and Baco Noir was developed by hybridisation because one parent belongs to Vitis vinifera and the other to Vitis riparia. Familiar examples of cultivars developed through crossing or hybridisation include Cabernet Sauvignon, Chardonnay, Muscat of Alexandria, Concord, Zinfandel and Tempranillo as well as more recent introductions such as Tarrango, Symphony and Regent.

the important grapevine virus diseases would substantially improve winegrape productivity and quality, thus improving efficiency. By far the most important scion virus disease is leafroll, which decreases both yield and quality. Fanleaf degeneration markedly impacts productivity but is caused by a virus spread by root-feeding nematodes and can be managed with appropriate rootstock choice. Leafroll resistance is not yet conclusively identified, though germplasm screening reports indicate genetic sources of resistance are available (Aboughanem-Sabanadzovic and Sabanadzovic 2015).

New selections in the future will reflect genuine genetic and phenotypic diversification rather than merely lineage tracking or differential virus infection. They will be routinely and intensively identified by robust DNA fingerprints — in mothervine blocks, in nurseries or in commercial plantings, by wineries receiving fruit that was expected to be of a specified selection by contract. The cost of DNA sequencing continues to plummet, so we expect to be able to have DNA markers that are reflecting the causal variation for phenotypic differences as a part of fingerprint technology. Today, some selections can be distinguished by neutral markers that do not predict specific phenotypes and some selections can be distinguished by the markers that cause specific phenotypes. A neutral marker does not have a functional relationship to the phenotypic difference; for example, microsatellite (simple sequence repeat) markers are not the cause of the differences in phenotypes among selections or cultivars although these markers may be used to distinguish among selections or cultivars (Regner et al. 2001). In contrast, some diagnostic markers actually indicate the difference in sequence that causes the phenotype difference (Battilana et al. 2011). As our understanding of gene function increases, more and more of the differences among selections will be clearly attributable to known genetic differences and those causal DNA differences will be suitable for identifying specific selections.

Crossing and hybridisation will continue as powerful methods for the combination of genetic traits. Molecular markers that predict certain phenotypes based on DNA differences are in widespread use now by winegrape breeders to select promising seedlings and to identify parents carrying traits of special interest, such as self-fertility, powdery mildew resistance or black fruit. Improvements to molecular markers will include markers for newly characterised traits, better predictive power and lower cost and shorter marker processing time.

Other methods for winegrape plant material improvement have been validated, though their commercial potential is presently limited by technological challenges and/or by regulations.

Winegrape cultivars with altered phenotypes have been created through recombinant DNA (GMO), gene editing (such as CRISPRCas9) and mutagenesis approaches (such as exposure to high doses of gamma radiation). With more information about gene editing targets and transgene functions, these methods will be applied to more winegrape cultivars, eventually with the goal of creating improved selections or cultivars for commercial production. To date, no recombinant DNA or gene edited grapevine cultivars or selections have been commercialised and the current lack of regulatory harmonisation among sovereign jurisdictions complicates the prospect of international trade in wine from gene edited or recombinant DNA grapevines.

Identifying effective host plant resistance to

Plant material innovation in winegrapes is improving in speed and accuracy due to better evaluation and validation methods. For example, refinements to microvinification practices, such as improved oxygen and temperature management, enable the production of small batches of wine from experimental cultivars and selections that closely predict the attributes of wine expected from commercial-scale fermentations. Historically, microvinification was, at best, a rough estimate of the commercial wine potential due to challenges driven by vessel size and lack of methods for controlling fermentation conditions.

Methods for examining the potential of seedlings and candidate new cultivars at all stages of selection will allow for more commercialisation decisions with viticultural and oenological observations conducted in a mechanised vineyard context using grape and wine chemistry and sensory analysis. While many winegrape cultivars introduced in the past were subjected to decades of lowintensity testing, future evaluation will be faster and better, incorporating multiple years and locations for robust testing and comparison.

WINEGRAPE DIVERSITY

Current winegrape diversity is driven by autochthony, tradition and marketing regionalism.

Conversely, international trade and globalisation tend to drive widespread cultivation of a few cultivars, which decrease winegrape diversity. Future winegrape diversity can be driven by consumer preference and satisfaction and will improve sustainability as well as wine demand.

Many — perhaps most — winegrape cultivars are essentially trapped in their region of origin, produced on a small scale, consumed locally and rarely traded internationally. This applies to recently introduced cultivars as well as traditional or heritage cultivars. A few cultivars are widely cultivated and traded

“Winegrape trellising and training innovation has fallen behind other grape categories … winegrape trellising and training innovation still has the opportunity to grow, with many important improvements likely to come from concepts that are now well-known and widespread in table grape production, such as divided overhead canopies.”

internationally. Few cultivars will go extinct in the sense that their plant material is completely lost worldwide due to tradition and producer inertia. Indeed, some obscure cultivars have inadvertently been preserved partly due to the lack of interest or ability to distinguish distinct types in mixed plantings.

In the future, there will be much more diversity in grape and wine composition than is available in the wine market or in the vineyard today (Dry et al. 2022). New genetic diversity, sometimes discovered among cultivars and selections but mostly the result of crossing and hybridisation, will help create a greater range in composition of pigments, flavour, aroma and mouthfeel compounds. For example, Muscat of Alexandria berries are high in monoterpenes and are used for the manufacture of highly aromatic and flavourful muscat wines. In contrast, Colombard berries are much lower in monoterpenes than are Muscat of Alexandria berries. Is Muscat of Alexandria producing the most monoterpenes physiologically possible in grape berries? Could a new cultivar sustainably produce 10 to 50 times more monoterpenes than Muscat of Alexandria?

While the lower bounds for the production of some compounds may have been identified among cultivars, it is premature to conclude that today’s winegrape cultivars reflect the physiological maxima for any important grapederived compounds except sugars. Through

trade allow for the dissemination of concepts, brands and products that historically may have been locally or regionally limited. The expected consequence for winegrape innovation is that existing diversity and new cultivars and selections will support product innovation that meets and creates consumer demand.

ROOTSTOCK IMPROVEMENT

Although rootstocks have little direct influence on grape composition and subsequent wine composition, both of which are chiefly driven by the scion cultivar or selection (Migicovsky et al. 2021), rootstocks have an essential role in providing protection against pests and diseases of grapevine roots and as the interface between scions and soil, which is particularly relevant to vine water status and adaptation to challenging soil chemistries. Major innovation in rootstock breeding is slow due to the testing cycle duration and the nature of the physiological interaction between scion and rootstock (Migicovsky et al. 2021).

New discoveries of genetic resistance to grapevine fanleaf virus (Djennane et al 2021), associated with fanleaf degeneration, will redirect rootstock breeding as this has not occurred since the beginning of grapevine rootstock improvement during the phylloxera crisis (Tello et al. 2019). Fanleaf degeneration is a widespread disease with the key symptom of lower yield, with yield loss up to 77% (Djennane et al. 2021).

methods, such as microvinification and vineyard evaluation, which increase confidence in the predictive power from laboratory and research vineyard scale to commercial application, though the commercialisation of improved plant material will remain an endeavour of multiple seasons of investigative viticulture and oenology in order to ensure that material makes important and significant contributions.

REFERENCES

Aboughanem-Sabanadzovic, N. and Sabanadzovic, S. (2015) First report of Grapevine leafroll-associated virus 2 infecting muscadine (Vitis rotundifolia) and summer grape (Vitis aestivalis) in the United States. Plant Disease 99(1):163-163.

Battilana, J.; Emanuelli, F.; Gambino, G.; Gribaudo, I.; Gasperi, F.; Boss, P.K. and Grando, M.S. (2011) Functional effect of grapevine 1-deoxyD-xylulose 5-phosphate synthase substitution K284N on Muscat flavour formation. Journal of Experimental Botany 62(15):5497-5508.

Cousins, P. (2005) Rootstock breeding: An analysis of intractability. HortScience 40(7):19451946.

Djennane, S.; Prado, E.; Dumas, V.; Demangeat, G.; Gersch, S.; Alais, A.; Gertz, C.; Beuve, M.; Lemaire, O. and Merdinoglu, D. (2021) A single resistance factor to solve vineyard degeneration due to grapevine fanleaf virus. Communications Biology 4(1):637.

the development and characterisation of more diverse breeding populations and cultivated and wild germplasm, the variation and upper limits for grape metabolites will be better understood. The boundaries or the ranges or the limits of the composition will increase.

The world’s diverse wine consumers appreciate a vast array of wines manufactured from numerous grape cultivars in many different styles. In the future, there will be more kinds and more differences among the kinds of wines and wine products — from sparkling wine to brandy to wine blends and more. Consumer demand and preference are not static and global exchange and international

Grapevine fanleaf virus is transmitted by certain migratory ectoparasitic nematodes, yet resistance to the nematode vectors does not provide much protection against virus transmission or the associated disease. Now that genetic resistance to the virus is identified and characterised, breeding new rootstocks that simultaneously provide protection against phylloxera and resistance against fanleaf virus is a viticultural imperative. New rootstock cultivars from this effort will increase yield potential and production efficiency, resulting in more effective use of land, water and other resources.

CONCLUSION

Winegrape cultivar and selection improvement will continue the current trajectories — a few cultivars will tend to dominate world trade and global production, and new cultivars and selections will meet specific demands and create opportunities for production efficiencies (such as improved mechanical harvesting) and new product development. New cultivars and selections will be developed with improved technological

Dry, I.B.; Davies, C.; Dunlevy, J.D.; Smith, H.M.; Thomas, M.R.; Walker, A.R.; Walker, R.R. and Clingeleffer, P.R. (2022) Development of new wine-, dried-and tablegrape scions and rootstocks for Australian viticulture: past, present and future. Australian Journal of Grape and Wine Research, 28(2):177-195.

Migicovsky, Z.; Cousins, P.; Jordan, L.M.; Myles, S.; Striegler, R.K.; Verdegaal, P. and Chitwood, D.H. (2021) Grapevine rootstocks affect growth-related scion phenotypes. Plant Direct 5(5):00324.

Regner, F.; Stadlbauer, A. and Eisenheld, C. (2000) Molecular markers for genotyping grapevine and for identifying clones of traditional varieties. In International Symposium on Molecular Markers for Characterizing Genotypes and Identifying Cultivars in Horticulture, Acta Horticulturae 546:331-341.

Tello, J.; Mammerler, R.; Čajić, M. and Forneck, A. (2019) Major outbreaks in the nineteenth century shaped grape phylloxera contemporary genetic structure in Europe. Scientific reports 9(1):1-11.

Walker, A.R.; Lee, E. and Robinson, S.P. (2006) Two new grape cultivars, bud sports of Cabernet Sauvignon bearing pale-coloured berries, are the result of deletion of two regulatory genes of the berry colour locus. Plant molecular biology 62:623-635.

WVJ

“…breeding new rootstocks that simultaneously provide protection against phylloxera and resistance against fanleaf virus is a viticultural imperative.”

How does a variable and changing climate impact budburst timing of winegrapes?

By Cindy Liles and Danielle Verdon-Kidd, University of Newcastle, New South Wales

Extreme weather events experienced in recent years have showcased the reality of the adverse impacts of a changing climate on agriculture. Winegrapes are especially vulnerable since their growing season is linked to a narrow range of climate influences, and hence any change threatens the timing of phenological development. The authors investigated the influence of changing springtime temperatures on budburst across Australia’s wine regions.

Budburst is the first phenological stage of winegrapes following the winter dormancy period. It is defined by bud formation, which traditionally occurs in early to mid-spring (Winkler 1974, McIntyre et al. 1982). The occurrence of budburst is strongly coupled to local air temperature. As such, changing temperatures is a recognised threat to this stage in phenological development (Webb et al 2007, Hall et al. 2016).

The potential impacts of changing budburst timing are multi-layered. Firstly, an earlier budburst may increase the risk of frost damage to vines should frost occur after budburst, impacting the season’s crop (Australian Wine Research Insititute 2017, Gobbett et al 2020). Secondly, since budburst is the first development event, alteration to budburst timing will have flow-on impacts on the timings of other phenological events such as véraison and overall maturity duration of winegrapes (Webb et al. 2011, Malheiro et al. 2013, Jarvis et al. 2019, Reis et al. 2020). Lastly, budburst occurring earlier in the year could result in standard climate accumulation metrics missing an early growth phase, and the classifications may be underrepresented (i.e. classification of ‘cool’ or ‘hot’ climate wines) (Jones 2007). Therefore, long-term variation in budburst timing may lead to growth in unfavourable conditions, resulting in potential changes to vineyard management and may impact wine quality and quantity and, ultimately the vineyard’s long-term success.

MODELLING BUDBURST ACROSS AUSTRALIAN WINE REGIONS

Despite the importance of budburst timing in the annual growth season, there is limited long-term records of observed budburst dates for Australian wine regions (at least publically available). Further, any data recorded at the vineyard scale would be expected to be highly dynamic and influenced by cultivar,

maintenance regime, as well as the grower’s interpretation of budburst.

Therefore in the absence of widespread recorded data, a modelling approach was used to estimate budburst timing. The theoretical (modelled) budburst date was calculated for each year (1910-2019) using a Growing Degree Day (GDD) calculation with a base of 4.5oC and a threshold of 450, as proposed by Moncur et al. (1989) and recently validated by Hall and Blackman (2019). The output from this calculation represents the number of days after 1 July on which budburst theoretically occurred, for example, 31 represents 1 August. This calculation has been developed for Shiraz winegrapes. This was applied to spatially gridded temperature data that covered all Australian wine regions (Bureau of Meteorology 2008).

The spatial analysis demonstrated that the timing of budburst dates varies significantly across Australian wine regions. Results show that, typically, budburst is expected to occur in September (with an overall median date of 25 September). However, some regions experience budburst in late August, whereas for wine regions located at higher elevation, this can extend into October due to their cooler climates.

IN BRIEF

■ Changing springtime temperatures, as a result of atherogenic climate change and large-scale climate drivers, threatens the timing phenological event of budburst for wine grapes

■ Budburst was modelled across Australia, using gridded temperature data to approximate the date of budburst between 1910-2019

■ Modelled budburst date has been gradually shifting to earlier in the year for most (95%) Australian wine regions, at an average rate of one day every 24 years

■ Interannual variability was observed and was correlated with Indian Ocean Dipole and Southern Annular Mode; however, no significant relationship was found between El Niño/Southern Oscillation and springtime temperature

■ Understanding the influences of variability in budburst timing can inform strategic management practices.

HAS CLIMATE CHANGE

INFLUENCED BUDBURST TIMING OVER THE CENTURY?

This research assessed the temporal trends of budburst timing over the period 1910-2019 for each wine region. A Mann-Kendall statistic was used to determine the direction (i.e., increasing or decreasing) of the trend for the median budburst dates within each wine region over the study period. The results confirm that budburst date has advanced in recent decades for the majority (95%) of Australian wine regions (Figure 1). However, some wine regions show no trend in the budburst date, including Alpine Valleys, Bendigo, Clare Valley,

Cowra, Goulburn Valley, Gundagai, Heathcote, Hilltops, Mudgee, Padthaway, Perricoota, Pyrenees, Riverina, Rutherglen, Southern Flinders Ranges, Strathbogie Ranges, Swan Hill, Upper Goulburn, and Wrattonbully. The majority of these wine regions share the characteristics of being cool-climate wine regions and are located at a higher elevation, with the exception of the Riverina wine region. Three wine regions — Glenrowan, Beechworth and King Valley — display an increasing trend, indicating that budburst for these regions is occurring later in the year in recent decades. Interestingly, these wine regions are also cool climates and at higher elevations.

Photo: Mark Smith

The Theil-Sen’s Slope of the Mann-Kendall statistic was calculated to quantify the rate of change (days/year) in budburst timing experienced across wine regions between 1910 and 2019. The rates of change are between -0.11 days per year in the Adelaide Hills, and 0.74 days per year in Beechworth. The average rate of change in modelled budburst dates across Australian wine regions is -0.04 days per year. This equates to the timing of budburst shifting one day earlier every 24 years. However, this could be as quick as one day every nine years, as modelled in the Adelaide Hills.

This continued shift to an earlier budburst timing coincides with the well-established trend in air temperatures associated with anthropogenic climate change. Australian air temperatures have warmed by 1.4oC since 1910, and since 1950 every decade has been warmer than the decade prior (CSIRO and Bureau of Meteorology 2018). This study considers the rate of change over the entire time period (1910-2019); however, given the accelerated temperature increases in the last 20 years, it could be hypothesised that the advancement of budburst would be more pronounced in the 21st century. Further, research has shown that global surface temperature will continue to increase regardless of which future emission scenario eventuates, with best estimates showing the increase between 1.5oC to 4.4oC by 2100 (IPCC 2021). Due to the projected

acceleration of temperatures, future changes in budburst timing may be more dramatic, which could result in an increased risk of dual warming as budburst shifts earlier in the season, whilst advancing to grape maturity timing.

Figure 2. Spatial influence of large-scale climate drivers (Indian Ocean Dipole (IOD) and Southern Annular Mode (SAM)) on budburst between 1910-2019 across the established Australian wine regions.

Figure 1. Mann-Kendell Trend of budburst between 1910-2019 across the established Australian wine regions. Figure adjusted from Liles and Verdon-Kidd (2022).

*For wine regions that have a correlation to climate drivers

**A negative value indicates that budburst occurs earlier during the positive phase of the respective climate driver

ARE LARGE-SCALE CLIMATE DRIVERS INFLUENCING BUDBURST?

On the interannual scale, Australia’s climate is influenced by a range of oceanic-atmospheric climate modes (CSIRO and Bureau of Meteorology 2018). The three major climate drivers that influence the continent are the El Niño/Southern Oscillation (ENSO), Indian Ocean Dipole (IOD) and Southern Annular Mode (SAM).

To investigate potential relationships between large-scale climate models and budburst timing, the index value for each year was extracted for the average of July, August and September (the three months leading up to typical budburst in the Southern Hemisphere). Then the modelled budburst dates were grouped according to climate phase (positive or negative), and a student’s t-Test was applied. A statistically significant difference in the mean budburst date between positive and negative phases of the climate modes was identified for almost three-quarters (72%) of the wine regions. IOD and SAM had

the greatest impact on budburst timing of the three climate drivers. Somewhat surprisingly (due to the well-known influence of ENSO on the Australian climate), ENSO was not shown to have a significant association with budburst timing for Australian wine regions. However, this is likely due to the very specific timing of budburst during spring and ENSO still may influence other stages of the phenological cycle.

Of all three climate modes studied here, IOD exhibited the most widespread influence, resulting in a significant impact on budburst timing for wine regions located on the northeast coast and South Australia, as well as a few regions in Western Australia.

The SAM was shown to significantly influence budburst timing for the wine regions Granite Belt, Hastings River, South Burnett and Perricoota. Previous research has identified that the positive phase of SAM during the cooler months is typically associated with drier and cooler conditions over the southwest and southeast coast (Gillett et al. 2006, Min et al 2013). However, the wine regions with significant SAM impacts on budburst identified in this paper are not spatially consistent, suggesting that there may be other modes masking the influence of SAM (such as IOD and ENSO). Further research is required to assess multi-model impacts (ie. drivers acting in combination) on budburst dates. This may also assist in untangling ENSO impacts that may not be observable in isolation.

To quantify the magnitude of the change in date, the mean budburst date for each climate phase was calculated for each wine region and climate driver. The difference in the mean budburst date between the different phases is shown in Table 1.

Several wine regions showed no influence of climate drivers on budburst date, including, Alpine Valleys, Beechworth, Bendigo, Clare Valley, Goulburn Valley, Heathcote, Hilltops, King Valley, Murray Darling, Padthaway, Pyrenees, Riverina, Riverland, Rutherglen, Southern Flinders Ranges, Strathbogie Ranges, Swan Hill and Wrattonbully. These wine regions share characteristics of being inland wine regions with lower interannual variability in budburst date. As such, these regions are more highly influenced by the long-term temperature trend, rather than interannual climate modes.

CONCLUSION

This study improves our understanding of the trends and variability in budburst timing for winegrapes across Australia’s economically and culturally valuable wine regions.

Temporal analysis showed modelled budburst dates have been progressively occurring earlier in the year for most wine regions over the 1910-2019 study period and highlighted significant interannual variability associated with the large-scale climate drivers the Indian Ocean Dipole (IOD) and Southern Annular Mode (SAM).

In terms of long-term planning for climate change, the temporal trends in budburst timing noted here are particularly important. It is projected that surface temperature trends will be accelerated in coming decades and, at the same time, large-scale climate drivers may increase in amplitude and frequency. Collectively, this may cause future changes in budburst timing to be more dramatic. This may also disrupt the subsequent stages of the phenological cycle and place winegrapes at greater risk from frost damage as budburst shifts earlier. Therefore, this information is crucial to prepare robust adaptation plans and identify future opportunities for the Australian wine industry. For further information see Liles, C. and Verdon-Kidd, D.C. (2022) Spatial and temporal trends in the timing of budburst for Australian wine regions. Australian Journal of Grape and Wine Research.

Table 1. Change in mean budburst date between positive and negative climate phases*, calculated between 1910-2019.

REFERENCES

Australian Wine Research Institute (2017) Frost management in vineyards. Fact Sheet Viticulture.

Bureau of Meteorology (2008) Mean monthly and mean annual maximum, minimum & mean temperature data (base climatological data sets) 1961-1990. Climate Data Services.

CSIRO and Bureau of Meteorology (2018). State of the Climate.

Gillett, N.P.; Kell, T.D. and Jones, P.D. (2006) Regional climate impacts of the Southern Annular Mode. Geophysical Research Letters 33(23).

Gobbett, D.L., Nidumolu, U. and Crimp, S. (2020) Modelling frost generates insights for managing risk of minimum temperature extremes. Weather and Climate Extremes 27.

Hall, A. and J. Blackman (2019). “Modelling within-region spatiotemporal variability in grapevine phenology with high resolution temperature data.” OENO One 53(2): 147-159.

Hall, A., Mathews, A.J. and Holzapfel, B.P. (2016) Potential effect of atmospheric warming on grapevine phenology and post-harvest heat accumulation across a range of climates. International Journal of Biometeorology 60(9):1405-1422.

IPCC (2021) Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. V. [Masson-Delmotte, P. Zhai, A. Pirani, S., C. P. L. Connors, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J. B. and T. K. M. R. Matthews, T. Waterfield, O. Yelekçi, R. Yu and B. Zhou (eds.). Cambridge University Press.

Jarvis, C.; Darbyshire, R.; Goodwin, I.; Barlow, E. and Eckard, R. (2019) Advancement of winegrape maturity continuing for winegrowing regions in Australia with variable evidence of compression of the harvest period. Australian Journal of Grape and Wine Research 25(1):101-108.

Jones, G.V. (2007) Climate change and the global wine industry. Proceedings of the 13th Annual Australian Wine Industry Technical Conference, Adelaide.

Liles, C. and Verdon-Kidd, D. (2022) Spatial and temporal trends in the timing of budburst for Australian wine regions. Australian Journal of Grape and Wine Research.

Malheiro, A.C.; Campos, R.; Fraga, H.; Eiras-Dias, J.; Silvestre, J. and Santos, J.A. (2013) Winegrape phenology and temperature relationships in the Lisbon wine region, Portugal. OENO One 47(4):287-299.

McIntyre, G.; Lider, L. and Ferrari, N. (1982) The chronological classification of grapevine phenology. American Journal of Enology and Viticulture 33(2):80-85.

Min, S.-K.; Ca,i W. and Whetton, P. (2013) Influence of climate variability on seasonal extremes over Australia. Journal of Geophysical Research: Atmospheres 118(2):643-654.

Moncur, M.; Rattigan, K.; Mackenzie, D. and Mc Intyre, G. (1989) Base temperatures for budbreak and leaf appearance of grapevines. American Journal of Enology and Viticulture 40(1):21-26.

Reis, S.; Fraga, H.; Carlos, C.; Silvestre, J.; Eiras-Dias, J.; Rodrigues, P. and Santos, J.A. (2020) Grapevine phenology in four Portuguese wine regions: modeling and predictions. Applied Sciences (2076-3417) 10(11):3708.

Webb, L.B.; Whetton, P.H. and Barlow, E.W.R. (2007) Modelled impact of future climate change on the phenology of winegrapes in Australia. Australian Journal of Grape and Wine Research 13(3):165-175.

Webb, L.B.; Whetton, P.H. and Barlow, E.W.R. (2011) Observed trends in winegrape maturity in Australia. Global Change Biology 17(8):2707-2719.

Winkler, A.J. (1974) General Viticulture, Univ. of California Press. WVJ

The mini greenhouse for vines!

A serendipitous tale of Savagnin in the Adelaide Hills

By Lucy Golding, Golding Wines, Adelaide Hills, South Australia

It all started with a case of mistaken identity, followed by an identity crisis, a struggle to be seen and understood, but ultimately ended happily with an underdog finding a place to put down roots and call home.

Whilst this might sound like the plot line of a Hollywood movie, the main character in this story is actually the little-known white variety Savagnin - a master of disguise, until it wasn’t. It’s introduction to Australia is a tale of serendipity and mistaken identity and whilst its eventual identity reveal caused headaches for many in the industry, we will be forever grateful that it found a home in our Western Branch Vineyard in the Adelaide Hills.

Before I share that story though, I should probably share a little of our own. After both studying and working in the fields of architecture and design, we launched the Golding Wines label in 2002. Darren had been running the family vineyard operations and managing fruit contracts for several years, so we knew we had exceptional fruit and a great site to work with. Our love of cool climate varieties and our optimism surrounding growth opportunities within the burgeoning Adelaide Hills wine region spurred us on to take the plunge and launch our own brand. It was a big year, we got married and launched a wine label within weeks of each other…buckle up!

The Golding family’s viticultural journey in the Adelaide Hills began seven years earlier in 1995 when Darren’s parents, Greg and Connie, sold the family home located in Ashton and purchased 33ha of vacant land just to the east of the Lobethal township. The chosen site, which fell within the Lenswood appellation, had previously been used to grow vegetables, mainly Brussels sprouts. Other than two existing dams on the property there was little else. So began the long process of turning this patch of land into a vineyard, and Darren and Greg worked side by side, with the help of many family members, to make this happen over the next few years. Much of the initial planting material for the vineyard was propagated by Greg in an onsite field nursery. His background in agronomy and extensive knowledge of horticultural practices was an

undeniable asset in this process. Darren continues to run our vine nursery business today. The original varieties planted back then were Sauvignon Blanc, Chardonnay, Pinot Noir, Cabernet Franc and Merlot.

Fast forward to 2006, we had taken the helm of the business and were looking to make some changes and plant some new varieties. First on our wish list was Albariño. There was an undeniable buzz around this aromatic and textural white Spanish variety in the market at the time. We enjoyed drinking it and we thought our site, with its elevated aspects and free draining soils, would be well suited to growing it. We initially planted half a hectare before following that up with a larger planting of 3.5ha a couple of years later. Little did we know that by 2009 we would be faced with a grim reality revealed by the genetic testing of Albariño source blocks in Australia. There was an imposter by the name of Savagnin in town and, more importantly for us, it was planted in our vineyard and we were heading steadfastly towards our first vintage of what should have been Albariño.

It was a marketer’s nightmare. Savagnin, also known as Traminer or Heida (let’s face it, neither of those were sexy options), sounded very similar to Sauvignon Blanc and consumers were going to be confused. Round table discussions were held with producers who found themselves in the same predicament. There was frustration and general sense of ‘so what the heck do we do now?’. Many pulled vines or grafted them over; in their eyes a market had disappeared overnight. For many, selling Savagnin was put in the too hard basket in a market where consumers were hungry for a popular Spanish drop and not an obscure and ancient variety grown in the Jura region in the French Alps.

As we hadn’t yet produced and marketed a wine as Albariño, we decided to take a different approach, stay the course, and we bottled our first vintage of Savagnin in 2009. That was the beginning of our Savagnin story and to be honest we haven’t looked back; we think there is much to love about this variety.

Using fruit from the same site Golding Wines produces two different expressions of Savagnin: the La Francesa Savagnin (left) is made with temperature-controlled fermentation in stainless steel tanks while the Cascara Savagnin (right) is made with prolonged fermentation on skins.

Savagnin thrives in our Western Branch Vineyard. Our vines are grafted on 10114 rootstock and planted on a high south easterly facing slope at an altitude of

around 400m. We spur prune to 30 buds and then shoot thin to maintain the desired crop level. Fruit set can sometimes be variable, but rarely problematic, with a degree of ‘hen and chicken’ that keeps yields moderate. The thick-skinned berries create resilience to disease pressure and provide protection during late season rain events. However, we’ve found that care needs to be taken to control phenolic extraction from the skins when pressing.

When ripe, Savagnin berries develop a pale yellow to burnished gold hue. We pick based on fruit flavour and in a typical season this lands around 12Be. It is a variety known for its high acidity and complex aromatics, and from the one site we produce two different expressions of Savagnin that capture both ends of the stylistic spectrum.

Our La Francesa Savagnin is made with clean temperature-controlled fermentation in stainless steel tanks. This results in a bright, aromatic wine with notes of lemon, pear on the nose, plenty of citrus and a hint of spice on the palate, balanced with the texture and subtle phenolic characters produced by those skins.

Our Cascara Savagnin sits at the other end of the spectrum, made with prolonged

Savagnin

fermentation on skins, creating a wine in a more traditional, oxidative style with plenty of texture. It has pronounced nutty almond notes, with pithy lemon and dried herbal characters, but retains a tight acid line. Both styles age well in bottle and are fantastic food wines, pairing with a wide variety of dishes, handling plenty of flavour including some chilli spice.

In the early years, post DNA testing and identity reveal, Savagnin definitely faced an identity crisis with wine consumers and wine commentators alike. No one quite knew what to make of this variety that sounded oddly similar to something else and that wasn’t what it was supposed to be. For us it came down to a few simple questions: is it suited to our site, do we enjoy the wines we are making and are we prepared for the ongoing process of education it would take to bring consumers along with us on this Savagnin path? Yes, yes and yes.

Fourteen years on from our first vintage of Savagnin we still delight in the moment a cellar door guest tries the variety for the first time, discovers the flavours and complexity it delivers in spades and leaves with a newfound favourite white. Whilst it might have originally arrived by chance, Savagnin will always have a home in our vineyard.

By Peter Dry, Emeritus Fellow, The Australian Wine Research Institute

BACKGROUND

Savagnin (suh-vuh-YAN) is a very old variety with place of origin likely to be Jura (north-east France). Based on DNA analysis, Savagnin is a parent of several well-known varieties including Sauvignon Blanc, Grüner Veltliner, Chenin Blanc and Verdelho; and thus grandparent of others; for example, Cabernet Sauvignon. Most intriguing is the discovery in c. 2000 that Savagnin and Pinot have a parent/offspring relationship.

Savagnin is known for its distinctive wines in Jura, particularly vin jaune (= yellow wine), an oxidised style similar to flor sherry (but not fortified). It is also used for conventional dry white wines in the Jura.

The global area in 2010 was 1989ha (with the largest area c. 500ha in the Jura). It is also grown in Switzerland, Austria, Slovenia and Czechia. Savagnin has many synonyms including Weisser Traminer (Germany and

Austria), Heida (Switzerland) and Traminer Bianco (northern Italy). Savagnin is a member of Traminer family and, unlike the other forms with aromatic and/or reddish berries, it is both non-aromatic and has white fruit.

It was planted in Australia from the late 20th century in the mistaken belief that it was the Spanish variety Albariño. After its true identity was determined in 2009, the number of producers declined. Currently, there are more than 80 wine producers in Australia, mainly in South Australia and Victoria, with McLaren Vale, Barossa Valley, Yarra Valley and Riverland being the main regions.

VITICULTURE

Budburst is mid-season and ripening is early. Vigour is moderate to high with semi-erect growth habit. Bunches are small to medium, well-filled to compact with small berries. Yield can be moderate. It is suitable

for spur pruning. Savagnin has average susceptibility to fungal diseases, is considered to be quite hardy and performs well in hot regions with good acid retention.

WINE

Savagnin has proven to be a versatile variety in Australia, with appealing dry and aromatic white wines in fresh styles with crisp acidity. Descriptors include citrus, white stone fruit and spices. It has great potential but suffers from similarity of name with the much better-known Sauvignon Blanc.

For further information on this and other emerging varieties, contact Marcel Essling at the AWRI (marcel.essling@awri.com.au or 08 8313 6600) to arrange the presentation of the Alternative Varieties Research to Practice program in your region.

Lucy and Darren Golding from Golding Wines in South Australia’s Adelaide Hills.

Alternative packaging and wine Should we move beyond the green bottle?

By Eric Wilkes, Kieran Hirlam and Neil Scrimgeour, The Australian Wine Research Institute, PO Box 197, Glen Osmond, South Australia 5064

With transport and glass packaging representing 74% of the greenhouse gas emissions produced during the lifecycle of Australian wine, these areas are obvious targets for improvement in the industry’s efforts to reduce its carbon footprint. In this fourth and final article in our ‘Towards Net Zero’ series, the authors compare the carbon footprint of different packaging options and the technical considerations involved in their selection.

BACKGROUND

In line with the international treaty on climate change adopted by 196 countries in Paris in 2015 (the Paris Agreement), the Australian wine industry has set a target of zero emissions by 2050. An emissions reduction roadmap is being developed to guide producers on how to reach this target. As part of this process, the Australian wine industry’s 2020-21 baseline emissions were measured as 1,770,997 tonnes of carbon dioxide equivalents (t CO2-e). Of this total, 49% of emissions were directly related to industrial processes and supply chain factors, with another 29% of emissions directly related to transport.

This assessment aligned closely with the Australian wine industry life cycle analysis (LCA) recently undertaken by the Australian Wine Research Institute (Hirlam et al. 2023) updating a similar study conducted by the AWRI in 2016 (Abbott et al. 2016). The updated LCA showed that transport and glass packaging (i.e. production and supply chain emissions) were hotspots that together represented 74% of the total life cycle. As such, it is obvious that packaging and transport must be a primary focus in the wine industry’s efforts to reduce its carbon footprint.

WINE PACKAGING

Over the history of wine, packaging has continued to evolve, from the days when wine was shipped and dispensed from clay and ceramic amphoras, to the evolution of the glass wine bottle and cork stoppers in the 17th century, through to current day where packaging options include different types of glass, bag-in-box, kegs, aluminium cans, plastic bottles, paper bottles and plastic pouches. When comparing the carbon footprint of different packaging options, it’s important to consider not just the energy used to

produce the packaging, but also how it affects emissions related to transport, which make up a significant part of wine’s overall footprint. Figure 2 shows differences in greenhouse gas emissions associated with five packaging formats under a domestic distribution scenario (Hirlam et al. 2023).

TECHNICAL CONSIDERATIONS FOR ALTERNATIVE WINE PACKAGING FORMATS

When evaluating the performance of wine packaging, the key factors are whether it will preserve the wine without tainting (adding unwanted flavours) or scalping (removing characteristic flavours), and whether it will sufficiently exclude oxygen and other environmental contaminants. Assessing these factors can be complex as they depend on the nature of the product, the environmental conditions it is likely to experience and the required shelf life.

Flavour impacts

Tainting and scalping are generally relatively well controlled in modern packaging, with well-defined protocols for the assessment of new packaging materials. It is still important, however, that all new variations on materials are carefully assessed, as the interactions with wine components are hard to predict, and unintended outcomes are possible. One example is the recent move to package wine in cans (a packaging format that has been well established for other beverages). Early adopters of this format found that a large proportion of wines developed ‘reductive’ characteristics after as little as three or four months in the package. While this was initially attributed to the low oxygen transmission rate of the can, recent research conducted at Affinity Labs and other locations has identified a different cause. Imperfections in the plastic lining of the cans have been shown to allow contact between the wine and the aluminium of the can, which then interacts with the SO2 in the

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Winery

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n Other winery (includingadditives and refrigerants)

Packaging

Figure 1. Relative impacts of different production aspects on the carbon footprint of packaged Australian wine. Destination bottling incorporates wine exported in bulk and packaged within the export market (Hirlam et al. 2023).

wine to form hydrogen sulfide (rotten egg gas). This process can be accelerated by higher levels of chloride in wine and the presence of copper. The same packaging format works well with other beverages, both alcoholic and nonalcoholic, because they do not have the same unique combination of components as wine (and ciders).

As the wine industry moves to less wellcharacterised options such as paper and flax packaging, understanding the possible interactions can only be achieved by welldesigned and implemented trials. Alternative packaging materials that include naturallyoccurring components such as cellulose and lignin have a high potential to react with wine components with yet-to-be-understood results. This also extends to the use of coatings inside the packaging such as waxes. These materials, while inert to many typical beverages, can potentially absorb low concentrations of aroma and flavour compounds that are important in wine. In short, the success of a package for other beverages does not mean that it will be suitable for wine, but this does not mean that such options should not be tried.

Oxygen ingress

The rate of oxygen transmission is a very important factor for wine packaging. The presence of oxygen leads to a number of reactions in wine, some of which are beneficial to its development. Generally, however, increased exposure to air/oxygen results in decreased shelf life and lower quality. It should be noted that, apart from sealed glass ampoules, all wine packaging allows some oxygen ingress. In traditional glass bottles, after the first three months in package, oxygen ingress is limited to that through the closure, leading to a controlled and relatively optimal environment for maturation and extended shelf life. However, this is not the case for some alternative packaging formats. For example, in bag-in-box packaging the collapsible plastic liner allows a much greater transmission of oxygen than a wine bottle closure, leading to a typical shelf life of less than 9 to 12 months. This shelf life can be extended by use of different polymers for the bag, some of which include oxygen scavenging material, but the gains seen in commercial applications to date have been limited. This demonstrates an obvious trade-off between the lower environmental impact for transport (lighter packaging and much greater space efficiency) and a significantly reduced shelf life.

There are similar issues for PET bottles, which are quite gas permeable compared to glass. In many cases the impacts of oxygen ingress in this format are similar to those seen for bag-in-box. Again, more advanced PET options include oxygen scavengers that can increase shelf life, but these present logistical problems as they need to be used as soon as possible after the bottle is formed to have the maximum possible effect. Currently there is limited information on the performance of plastic pouches and other newer alternatives such as paper and flax bottles. Aluminium cans and bottles do have potential to protect wine from oxygen at least as well as glass bottles but, as has already been discussed, a membrane must be included to prevent contact between the wine and the aluminium.

Transporrt

Another important aspect of wine packaging is the ability to transport the product, with weight, robustness and packing efficiency all being important factors. Heavier packaging takes more energy to transport and this is the driver behind the development of lighter-weight glass bottles that are increasingly being used in the Australian wine industry. Many of the decisions on how much glass can be removed from bottles to reduce their weight comes down to the robustness of the package to the rigours of domestic or international transport. Similarly, other alternative packaging formats must be robust enough not to break during transport and also be able to resist scuffing or other external damage to ensure that the product is presentable when it reaches its final market.

Overall, alternative packaging can provide a viable alternative to glass bottles, achieving a lower carbon footprint through lower-energy production and transport energy savings from

being lighter and more space efficient. There is a trade-off, however, with the shelf life of the products being generally shorter. Technology is continuing to evolve and newer materials that address these issues may become available in the future.

LONG-TERM WINE AGEING

Given a large proportion of wines are consumed just a few hours after being purchased, it is worth considering how important it is for wine to be in a package (such as a glass bottle) that supports long-term, multi-year ageing. One response to this point is that some wines do require bottle ageing, either because they are marketed as premium products that are suitable for cellaring, or due to specific legal requirements of their production area. In these cases it is obvious that the use of a packaging format with the shelf life of glass is important. While alternative packaging options may one day be able to give the required low levels of oxygen transmission for long-term maturation, no current alternative has proven suitable.

While this requirement exists for some wines, many wines are intended for immediate consumption, which might suggest a lower requirement for extended shelf life. However, the time from purchase to consumption is often by far the shortest part of the supply chain. The shelf life of a product must take into account the time from when it is packaged, through storage in a warehouse until it is purchased by the retailer or sold through cellar door. There is also the delivery time to market, which can be six to 12 weeks for some destinations. Finally, many major retailers demand at least six months of shelf life on products before they enter their distribution system to ensure they are not left with unsalable stock. This means

Figure 2. Differences in greenhouse gas emissions associated with packaging type as modelled for domestic distribution from a recent life cycle analysis of Australian wine (Hirlam et al. 2023)

that most wine producers prefer to have at least 12 months of usable shelf life on products to ensure their stock lasts through to the next vintage. Even for high-volume products that may be packaged many times during the year, the requirements of the supply pipeline realistically mean that a minimum of six to nine months’ shelf life are needed. This length of shelf life is achievable with bag-in-box packaging, indicating that it is possible to meet these timeframes with alternative packaging formats. It is also possible that supply chains may evolve to allow packaging closer to market and with smaller packaging runs, which would allow much shorter shelf life requirements.

WHICH PACKAGING FORMATS HAVE THE LOWEST EMISSIONS?

In 2010, the two Nordic alcohol monopolies Systembolaget and Vinmonopolet conducted a study through Bio Intelligence Service S.A.S (Tostivint et al. 2010) comparing life cycle impacts, including greenhouse gas emissions, for a range of packaging systems spanning glass, bag-in-box, stand-up-pouch and PET formats. The data and results are specific to the products selected, the Nordic market and the transport conditions between the winery locations and the packaging locations. In this study glass fared very poorly compared to other options, with 10-litre bag-in-box (BiB) having the lowest emissions, and all other alternatives having at least half the CO2 footprint of a traditional 750mL bottle (Figure 3). This study also showed interesting observations about packaging volume, showing that smaller volume wine packages exhibited higher emissions intensity than larger equivalents (e.g. 375mL glass bottles exhibited 32% more emissions than 750mL glass bottles).

ARE THERE WAYS TO IMPROVE THE EMISSIONS ASSOCIATED WITH GLASS?

The Nordic study assumed single use glass; however, in recent times there has been a push in some markets to introduce a mandatory re-use target for glass packaging. The wash and re-use process does have the potential to address some of the emissions associated with glass bottle manufacture. There are, however, obvious challenges for such schemes in many markets, primary among them being the need for stewardship programs to ensure that used glass gets back to the source for reuse. Without an efficient program and the required infrastructure to achieve this, it is difficult to effectively implement such programs.

Packaging format

Mandatory programs also present significant challenges for wine in bottle that is transported internationally, with it unclear how such bottles would be returned for re-use.

The glass industry is also addressing its emissions with significant research and commitment to alternative energy sources, such as the use of hydrogen rather than carbon-based fuels. There is also a move by producers to use oxygen rather than air in glass production to improve efficiency. These measures have the potential to significantly reduce the emissions from glass production; however, they cannot address the transport emissions associated with the weight of the packaging and the high proportion of unused space in a wine carton. In these respects, lighter packaging that is much more space efficient will always have a significant carbon footprint advantage, regardless of the distance that a product must travel.

RECYCLING OF DIFFERENT PACKAGING MATERIALS

In 2018 the Australian Packaging Covenant Organisation (APCO) set recycling targets for 2025, which include:

• a move to 100 per cent reusable, recyclable or compostable packaging

• 70 per cent of packaging being recycled or composted

• 50 per cent average recycled content across all packaging

• the phase out of ‘problematic and unnecessary single-use plastics packaging’.

Glass packaging has a recycling rate of more than 70% in Australia, largely attributed to the well-established glass recycling infrastructure in the country, as well as ongoing efforts from major glass producers to increase the rate of glass recycling across their plants. The proportion of cullet (recycled glass) used as a feed for glass production can vary depending on the availability of recycled glass, market demand and the technological capabilities of glass manufacturers. In Australia, the average proportion of cullet used in glass production is typically around 35%. Incorporating higher levels of cullet in glass production can lead to slight variations in colour or transparency. However, advancements in glass sorting and processing technologies have significantly improved the quality of recycled glass, making it more suitable for high-quality bottle production. Using more cullet in glass production has a positive impact on the recyclability of glass bottles and can also enhance production efficiency and lower production costs. It can also result in reduced fuel consumption required for glass melting, and lower greenhouse gas emissions; however, there is a need to determine how this applies to products tailored for the wine industry, including different coloured and

lightweight glass formats.

Figure 3. Normalised comparison of emissions (global warming potential) for different wine packaging formats and sizes. Selected formats include glass, bag-in-box (BiB), stand-up-pouch (SuP) and PET packages. Data has been normalised against a standard 750mL glass bottle and represents emissions intensity for 1000L of product packaged and distributed within the defined market. Data sourced from Tostivint et al. (2010).

PET is one of the most commonly used plastics in beverage bottles, especially for wine products. The recycling rate for PET bottles is lower than glass (APCO 2021), but it has been steadily improving in recent years. The current recycling rate for PET is estimated to be around 36% in Australia. Efforts to increase recycling rates for PET have been underway, including increased public awareness and infrastructure investments. PET recyclability is influenced by the content of recycled PET (rPET) in new PET packaging and the degree of cross-linking present. The higher the content of rPET in new PET packaging, the greater the reduction in the use of virgin plastic and the overall environmental impact. However, there are limitations on the amount of rPET that can be used in certain applications due to performance, safety and regulatory requirements. When looking at alternative packaging material, replacing virgin PET with rPET may reduce greenhouse gas emissions by 50% (Paben 2018).

Overall, for post-consumer recycled content, glass packaging currently has a higher recycled content than plastic packaging, such as PET, with current levels trending towards the 2025 APCO targets (37% at 2019-20, targeting 50% by 2025). In comparison, the recycled content currently being achieved for plastic packaging is well below the 2025 APCO targets. Although PET is trending slightly better (14% at 2019-20, targeting 30% by 2025), on average, significant efforts still need to be made for PET packaging to achieve the 30% target, while providing the structural and protective aspects required for wine packaging.

As highlighted above, the recycling rates for PET are a target of industry and have the potential to significantly reduce the carbon footprint of this form of packaging. However, the liners used in a range of products such as BiB present their own unique issues. The majority

of these liners are a multilaminate of different plastics and a metallic layer. This makes them difficult to recycle as they first need to be separated into the different constituents, which is not a straightforward process. There are efforts underway to introduce new technologies to facilitate this process, but since it is a specialised process, a dedicated stewardship program would be needed to ensure that the material ends up at an appropriate facility. Unfortunately, all too often, when such material is put into normal recycling streams it ends up in landfill because it does not fit under the simple plastics classification.

There are similar issues for a range of other alternative packaging options such as Tetra Pak and other paper-based options. If they are made up of multilaminates including plastics or metallic layers, they cannot easily be recycled under general recycling programs. Even the natural wax-based layers used in some alternative beverage containers make them unsuitable for recycling (although they do have better compostability in landfill). To ensure the recyclability of any of these options, programs and infrastructure need to be in place to allow the material to be reprocessed meaningfully and not just go to landfill.

CONCLUSIONS

There is a direct and pressing need for all aspects of society to reduce greenhouse gas emissions and the wine industry needs to play its part. An obvious target is to reduce the impact of both the production of packaging materials and the related energy cost of transportation. Moves to adopt alternative packaging have significant potential to achieve these goals; however, these alternatives must be able to meet the requirements of wine to ensure it reaches the consumer in optimal condition. At the same time, investments are

needed by both industry and governments in infrastructure and stewardship programs to allow the efficient use of alternative packaging and to ensure that its use is consistent with the overall goals of reducing waste and increasing recycling. Another important aspect is consumer acceptance of non-traditional packaging formats, but that is an area to be explored at another time.

REFERENCES

Abbott, T.; Longbottom, M.; Wilkes, E. and Johnson, D. (2016) Assessing the environmental credentials of Australian wine. Wine Vitic. J. 31(1):35-37.

Hirlam, K.; Longbottom, M.; Wilkes, E. and Krstic, M. (2023) Understanding the greenhouse gas emissions of Australian wine production. Wine Vitic. J. 38(2):34-36.

Paben, J. (2018) Quantifying environmental benefits of recycled plastic. Accessed August 2023, from: https://resource-recycling.com/ plastics/2018/08/22/quantifying-environmentalbenefits-of-recycled-plastic/

The Australian Packaging Covenant Organisation (2021) New APCO report maps the state of packaging in Australia and progress on Australia’s 2025 national packaging targets. Available from: https://apco.org.au/ news/20Y4a00000000Q9EAI

Tostivint, C.; Beton, A.; Massari, F. and Guern, Y.L. (2010) Nordic Life Cycle Assessment Wine Package Study. Bio Intelligence Service S.A.S

ACKNOWLEDGEMENTS

AWRI communications are supported by Wine Australia, with levies from Australia’s grapegrowers and winemakers and matching funding from the Australian Government. The AWRI is a member of the Wine Innovation Cluster in Adelaide, South Australia. WVJ

The journey to better understanding the direct-to-consumer channel

By Samantha McKee1, Justin Cohen2, Sean Sands1 and Jason Pallant3

Despite the substantial amount of research that has been carried out on the director-to-consumer (DTC) channel in a marketing context for more than 20 years, there remains a pressing need for analysis of consumer behaviour in the channel in the context of the wine sector. The authors outline how their research team is looking to address this information gap and, in the interim, offer some recommendations for wineries on utilising the DTC channel.

The difficult state of the wine industry is now at the forefront of discussions. This situation continues to be exacerbated by ongoing economic and political headwinds. Wine brands, particularly small and medium-sized enterprises (SMEs), must take charge of their own destiny. There is a need to better understand how a wine business can drive demand and generate sales that deliver sufficient profit margin. One such way that wine businesses have done so more recently is by investing in their own direct-to-consumer (DTC) channels to complement trade efforts via physical retail, including their cellar door, on-premise and ecommerce channels. The COVID-19 pandemic was a catalyst for redirecting sales through the online DTC channel when on-

premise sites and cellar doors were closed or restricted. This change also created significant opportunities for wine brands to develop technology capabilities and streamline operations to generate profitability in trying times.

There is hope in the wine community that DTC can become a valuable lever for SME wine brand growth. To that effect, in June, many members of industry gathered face-to-face in Sydney for the Direct-toConsumer Wine Summit organised by the Wine Communicators of Australia and Smile Marketing. Experts from brands and consultancies shared their views on bestpractice and from their own experiences on how the DTC channel can be used as opportunities for growth. Despite the diverse

backgrounds of those who spoke, there were common themes that emerged around two key areas being customer experience and the customer journey. Speakers discussed the role of personalisation, emotion and technology in the provision of customer experience. The nuances of relationship marketing in a digital environment and the generation of datadriven insights across the customer journey were also explored. It was a valuable day of knowledge exchange and a good initial barometer of the current state of the DTC channel in the Australian wine industry.

CONCEPTUALISING AND REFINING THE DTC OPPORTUNITY

Our research team recently published a review of the DTC business model and

1Swinburne University of Technology, Melbourne, Victoria

2Ehrenberg-Bass Institute for Marketing Science, University of South Australia 3RMIT University, Melbourne, Victoria

outlined future research directions (McKee et al. 2023). Despite the recent increased interest in the evolution of the DTC business model, the DTC channel has been researched for over two decades. Eighty-one academic articles, in general and not winespecific, that investigated DTC in a marketing context were reviewed using a structured method to reach our conclusions. Whilst there is a strong evidence-base to work from, there is a pressing need to descriptively document DTC channel behaviour and investigate what theories play a role in driving consumer behaviour in this channel.

REFINING THE DTC OPPORTUNITY IN A WINE CONTEXT

There is a need for empirical work on the DTC channel in the wine sector. Our research team is trying to remedy that in the months ahead. The next phase of our research is conducting interviews with wine brands to better understand the key impediments and success factors in delivering experiential value to DTC channel users. As part of these discussions, we aim to understand the DTC business objectives of wine brands and explore how and why various marketing levers are being utilised or ignored to reach these goals and whether these are based on acquisition and/or retention strategies.

Due to the complex nature of wine as a category and the inability to directly interact with the product or a salesperson in the DTC channel, it is possible that consumers’ perceived risk and brand trust could have an amplified impact in this digital context on the purchase process. Therefore, we are looking to extend the work of Gilboa et al (2019) on relationship marketing in small businesses into the online DTC channel. Our interviews will explore if factors such as these moderate experiential value across Lemon and Verhoef’s (2016) customer journey framework, and from a brand perspective, the rationale and outcomes of their investments across the pre-purchase, purchase and postpurchase stages.

THE JOURNEY HAS JUST BEGUN

Our research in this specific channel is only just emerging. However, there are still recommendations that can help wine brands utilise the DTC channel as part of a strategy to achieve sustainable growth. It has

been written extensively in this journal that strategies aimed at increasing the size of a brand’s customer base (penetration) and not based on increasing loyalty (frequency) are the way to sustainably grow (Sharp 2010). This not only applies to brand growth, but in the context of a growing sales channel, in this case DTC. Cohen (2021) has previously written on how this applies in sales channels and provides guidance on how wine brands can effectively manage their physical availability. Cohen and Dawes (2022) illustrate the role of penetration in growth, specifically in a physical wine retail context, and further illustrate the important role of light and occasional buyers in delivering sales. There is opportunity to validate this pattern in DTC, but since these two phenomena hold in other channels and contexts one can assume it will here as well.

In this aim to increase penetration, wine brands should think about how the introduction or better management of their own DTC channel is a form of innovation that if properly supported can unlock barriers to purchase by making their wine available and easier to purchase by potential buyers. Having a seamless DTC customer experience that is easy to navigate will help. Furthermore, your cellar door is likely located regionally and away from population centres. As an SME wine brand, it will be challenging to be ranged in major Australian liquor retailers and, if you are, the terms of that relationship on a per bottle basis may not be as profitable as you would like. Efforts to build relationships with cellar door visitors and drive them to your DTC site are

part of a penetration-building strategy, but the only way to truly scale a wine brand’s DTC business will be to reach a much larger cohort of potential buyers.

This is where mental availability-building activities that focus on improving the recall of your brand in category buying situations come into play (Romaniuk and Sharp 2016). All buyers matter, but the potential scale of reaching infrequent, lapsed or category buyers who have never purchased you before is where the opportunity lies. Wine brands need to consider how they will reach these types of consumers and direct them to their DTC site to sustainably grow this channel. Mass media will deliver the most reach, but most SMEs may not have the budgets to utilise this medium. Therefore, understanding how to leverage a penetration building strategy utilising social media channels will become critical (Cohen 2022).

We look forward to sharing the findings of our qualitative stage of research in a future issue of this journal. We will refine our research direction based on our findings and then investigate the DTC model from a consumer perspective.

REFERENCES

Cohen, J. (2021) There is more to sales strategy than just distribution. Wine & Viticulture Journal 36(3):72-73.

Cohen, J. (2022) How wine brands can effectively use social media. Wine & Viticulture Journal 37(1):83-84.

Cohen, J. and Dawes, J. (2022) Marketing is fundamental for South Australian businesses. Business SA, https://business-sa.com/news/ marketing-is-fundamental-for-south-australianbusinesses

Gilboa, S.; Seger-Guttmann, T. and Mimran, O. (2019) The unique role of relationship marketing in small businesses’ customer experience. Journal of Retailing and Consumer Services 51:152-164. https://doi.org/10.1016/j.jretconser.2019.06.004

Lemon, K.N. and Verhoef, P.C. (2016) Understanding customer experience throughout the customer journey. Journal of Marketing 80(6):69-96. https://doi.org/10.1509/jm.15.0420

McKee, S.; Sands, S.; Pallant, J.I. and Cohen, J. (2023) The evolving direct-to-consumer retail model: a review and research agenda. International Journal of Consumer Studies. https://onlinelibrary. wiley.com/doi/10.1111/ijcs.12972

Romaniuk, J. and Sharp, B. (2016) How brands grow: Part 2. Melbourne, Oxford University Press. Sharp, B. (2010) How brands grow. Melbourne, Oxford University Press.

“…wine brands should think about how the introduction or better management of their own DTC channel is a form of innovation that if properly supported can unlock barriers to purchase by making their wine available and easier to purchase by potential buyers.”

Top-line results from Vintage 2023

By Peter Bailey, Manager - Market Insights, Wine Australia

Peter Bailey drills down into some of the nitty-gritty from Wine Australia’s National Vintage Survey for 2023.

According to the ‘National Vintage Report 2023’, released by Wine Australia in July, the 2023 Australian winegrape vintage is estimated to be 1.32 million tonnes, down 24 per cent on the 2022 crush and the lowest recorded since 2000. Compared with the 10-year average, the reduction in the crush (466,000 tonnes) is equivalent to approximately 325 million litres of wine.

The smaller national crush was mainly driven by declines in the big three inland regions of the Riverland, Riverina and Murray Darling-Swan Hill due to seasonal conditions as well as demand-driven effects related to inventory pressures. It was impossible to determine what share of the overall reduction, compared with an average vintage, could be attributed to demand-driven effects as opposed to seasonal conditions.

KEY VINTAGE DRIVERS

The 2023 vintage is widely reported to have been the most difficult and challenging in at least the past 20 years. A third consecutive La Niña event produced the wettest year since 2011 and it was also Australia’s coolest year since 2012. Persistent winter and

spring rainfall across much of South-Eastern Australia made access to vineyards difficult as well as causing flooding in some regions. The cool, wet conditions through spring and summer in some regions also led to lower yields, delayed ripening and challenges managing disease.

Further reducing the size of the crush were winery inventory pressures resulting in some yield caps being imposed, uncontracted grapes not being sold and/or vineyards being temporarily taken out of production.

Despite the challenges, the exceptionally cool season was conducive to producing high quality fruit with excellent flavour development.

CRUSH OF RED AND WHITE GRAPES

The red grape crush declined by slightly more than the white crush. The crush of red grapes in 2023 (711,777 tonnes) declined by 26% compared with 2022 and was 25% below the 10-year average (943,146 tonnes), while the white crush (605,321 tonnes) fell by 22% compared with 2022 and 28% below its 10year average (839,013 tonnes.).

There was very little change to the make-up of the top 10 varieties, with the same varieties included as last year. There

were only four reds in the top 10, but these accounted for 53% of the group — down from 55% in 2022. Shiraz and Sauvignon Blanc increased their percentage of the total crush, while Cabernet Sauvignon, Chardonnay and Merlot lost share. Pinot Noir and Sauvignon Blanc both moved up one place, with Sauvignon Blanc now the fourth-largest variety displacing Merlot.

For reds, the crush of the major three varieties all declined, but Shiraz (down 20%) declined by a lower percentage than Cabernet Sauvignon (down 39%) and Merlot (down 31%). The lower relative decline in Shiraz was due to the increased crush of Shiraz in the Barossa Valley, up 50% on 2022 to almost 44,000 tonnes, the biggest Shiraz crop in the region since 2017.

The crush of other red varieties also declined but not to the same extent as the big three. For example, Pinot Noir declined by 11% and Grenache by 10%.

For whites, the tonnes crushed of all the major varieties declined but the extent of the reduction was quite varied. Chardonnay remained the major white variety, but the crush fell by 29%. Sauvignon Blanc was clearly the number two white, but the reduction

Photo: Wine Australia

in its crush was much lower than Chardonnay at 5%. The lower relative decline in Sauvignon Blanc was due to the crush of the variety increasing in the two biggest producing regions, Riverland (up 5%) and Riverina (up 2%).

Other whites to decline included Pinot Gris/Grigio (down 23%), Semillon (down 11%) and Muscat Gordo Blanco (down 16%).

Among the top 20 varieties (both red and white), Riesling ranked seventh in tonnes crushed and declined by the smallest percentage (down 1%). There were only small declines of Riesling crushed in the two major regions producing the variety — Clare Valley (down 0.2%) and Eden Valley (down 2%). The Riesling crush increased in Langhorne Creek (up 166%) and Padthaway (up 28%); the increased crush comes after relatively low crushes in each of these regions in 2022.

STATES AND REGIONS

South Australia (SA) retained its position as the largest contributor to the crush with a 55% share of the national total, despite its secondsmallest crush since 2007 (and down 18% on 2022). The SA crush was very similar to its 2020 size and 17% below its 10-year average.

New South Wales (NSW) was the second largest contributor with 27% of the national total. Its crush decreased by 28% compared with 2022 and was 36% below its 10-year average.

Victoria was the third largest contributor with 13% of the crush but recorded the largest relative decline at 40% down compared to 2022. It was also 43% below its 10-year average.

The estimated crush from Western Australia (WA) was very similar to its 2022 tonnes and represented a 3.5% share of the national crush. The state’s crush was 24% above its 10-year average.

The estimated crush from Tasmania was relatively flat while Queensland was up 25% on 2022, off a very small base (less than 500 tonnes).

The main reduction in the crush came from the three large inland wine regions: the Riverland, Murray Darling-Swan Hill and Riverina. The crush from these regions combined was down 28% (to 899,936 tonnes), whereas the crush from the rest of Australia’s 59 GI wine regions and 26 GI zones together was only down by 15% compared with 2022 (at 417,162 tonnes). This meant that the large inland regions reduced their share of the national crush to 68%, compared with the long-term average of 74%.

Many regions crushed more in 2023 than in 2022, contrary to the overall result, including the Barossa Valley (up 34%), Margaret River (up 9%) and Yarra Valley (up 18%).

Shiraz was the main driver for the increased crush in the Barossa Valley, but other varieties also increased including Cabernet Sauvignon (up 7%), Grenache (up 19%) and Merlot (up 23%).

For Margaret River, three of the region’s top four varieties were chiefly behind the overall increase, with the crush of Sauvignon Blanc up 17%, Cabernet Sauvignon up 22% and Chardonnay up 28%.

In the Yarra Valley, the region’s biggest three varieties made the greatest contribution to increased tonnages with Pinot Noir up 38%, Chardonnay up 14% and Shiraz up 10%.

In NSW, the crush across the Central Ranges GI Zone (Orange, Mudgee and Cowra) was up 50% in 2023, after being down 18% in 2022. Driving the increased crush in the zone was Chardonnay, Shiraz and Cabernet Sauvignon.

Figure 1. Australian winegrape crush and yield 2013-2023.

Figure 2. Winegrape crush by colour over time.

Figure 3. Average winegrape purchase value by source and colour.

WINEGRAPE AVERAGE PURCHASE PRICES

The average winegrape purchase price increased by 2% to $642 per tonne as a result of increases in the average price paid for red and white grapes from cool-temperate regions, together with the increased share of grapes from these regions in the overall mix, countering the reduction in the average price paid for grapes from the warm inland regions (see Figure 3).

The average price paid for grapes across the cool-temperate regions increased by 4% in 2023, with reds up by 3.6% and whites up by 5%. The average price paid for cool-temperate reds was $1585 per tonne, 28% above 2015 (the first year of the National Vintage Survey in its current form) but 7% below the peak of $1707 in 2020. The average value for cooltemperate whites was $1391 per tonne, which is 43% higher than it was in 2015 and higher than ever previously reported.

Among the top 10 red varieties from cool-temperate regions, average values for Cabernet Sauvignon increased by 4% and Grenache by 3%, while Shiraz and Merlot decreased slightly. The big mover was Pinot Noir — up 8% to be the highest-valued top 10 red variety on average across these regions. Of the top 10 cool-temperate whites, Chenin Blanc (up 14%) had the largest increase in average value, while Riesling was the only one to decrease (down 3%). The average value for Chardonnay was up by 5% and Prosecco was up by 1%.

In contrast to the cool-temperate regions, the average price paid for the inland regions’ grapes decreased by 11% in 2023, with reds down by 21% to $304 per tonne, driving most of the overall decline, and whites down by 5% to $399 per tonne. The average value for purchased reds from inland regions was lower than ever previously reported, 6% below the 2015 figure, and 54% below its recent peak of $659 per tonne in 2020.

The average value for inland whites was 52% higher than the 2015 figure and the third highest since 2008. The average value for reds was 24% lower than the average value for whites, compared with being 8% lower in 2022. Prior to 2022, reds have been an average of 30% higher than whites since 2008.

Across the inland regions, average values for all the top 10 reds were down, with the average value for Shiraz falling 22% to $279

Average value ($/tonne)

per tonne, Cabernet Sauvignon falling 25% to $268 per tonne and Merlot falling 24% to $276 per tonne. Pinot Noir had the highest-value and the smallest decline of the top-10 inland reds — down 9% to $621 per tonne.

Among the top 10 inland whites, Prosecco had the highest average value — $655 per tonne — followed by Sauvignon Blanc at $536 per tonne. Gewürztraminer was the only one of the top 10 to increase in average value (up 1%). The average value for Chardonnay decreased by 8% to $378 per tonne.

SUMMARY

Table 1 illustrates where Australia’s grape supply is under most pressure from falling global demand — in red winegrapes from the warm inland regions. Not only did the crush of reds in the warm inland regions fall by 30% in 2023 (the second successive decline in tonnes crushed), but the average price paid for red grapes declined by 21% (the third successive vintage where red grape purchase prices have declined). In the Agricultural Commodity Report released in March 20231, ABARES forecast the average purchase price for the key inland red varieties of Shiraz, Cabernet Sauvignon and Merlot to be relatively flat in 2024.

One of the key drivers for the significant decline in red prices in the warm inland regions, despite the drop in tonnes, is that globally, sales of commercial wines (less than US$10 per bottle) have been falling and this is impacting more significantly on red wines compared with whites. Most of the production from the warm inland regions goes into commercial wines. Exacerbating this situation was a record red grape crush in the

1https://www.agriculture.gov.au/abares/research-topics/ agricultural-outlook/wine-and-winegrapes

inland regions in 2021, which also came at the same time as the duties on Australian wine to mainland China were imposed; exports to China were predominantly red wine.

Data from the IWSR shows that the value of commercial wine sold globally fell by 1% per annum between 2017 and 2022. In contrast sales of premium wine (US$10 or more per bottle) over the same period increased by 3% per annum. The IWSR has forecast that sales of commercial wines will continue to decline out to 2027, albeit at a lower rate of 0.2% per annum. It has also forecasted premium wine sales to grow over the same period but at a slightly lower rate compared to the previous five years of 2% per annum, with tough global economic conditions (inflation and higher costs of living) having an impact on growth rates.

Apart from the global economic conditions, which have impacted on discretionary spending, health and wellness trends are also playing into these global wine market trends. Consumers are moderating their alcohol consumption. The combined impact is that less wine is being consumed per person globally, particularly in mature markets such as the United Kingdom, the United States and Australia. On top of this, Australia must compete with wine produced from other countries, particularly the major European wine producers of France, Italy and Spain which combined produce more than 10 times the volume of wine that Australia produces.

All of these factors impact on demand for Australian wine and ultimately Australia’s supply base, both in terms of tonnes produced and prices paid for grapes. Australian wine companies are already making tough business decisions based on these changing market fundamentals.

Table 1. Average value and year-on-year changes for grapes by source and colour

The consumer preference for lower alcohol Are there lessons from beer?

By Kym Anderson, School of Economics and Public Policy, University of Adelaide, and Crawford School of Public Policy, Australian National University. Email:kym.anderson@adelaide.edu.au

Australian brewers are world leaders in the way they’ve developed various low and no alcohol (Lo-No) beer products. What lessons and prospects does their experience give for similar wine products for the Australian and New Zealand industries?

IN BRIEF

■ Brewers were the first to respond to consumers’ increasing appetite for lower- and no-alcohol beverages, developing Lo-No beers that have appealed to their traditional customer base.

■ The prospects for lower-alcohol wine continue to depend on the development of new, affordable technologies.

■ Australian consumers of beer have shown most interest in midstrength products while Australian wine consumers in the US have also expressed most interest in the same category, suggesting this should be the target zone for innovators.

As incomes have grown and with it a greater desire for healthy living, there has been a consumer tendency since the 1970s to move from quantity to quality of beverages (the premiumisation of the markets for wine, beer and spirits). Now another quiet evolution is taking place in Australia and other higher-income countries that also is leading to lower alcohol consumption per capita: an increasing preference for lower- and no-alcohol (Lo-No) beverages.

According to IWSR, global sales in the Lo-No beverage category exceeded US$11 billion in sales in 2022. That is expected to increase by one-third by 2026, making it by far the fastest growing segment of the alcohol beverage market (Dingwall 2022).

Brewers were the first to respond by developing, through new technologies, flavour

profiles of Lo-No beers that have appealed to their traditional customer base. Wineries, by contrast, have come up with few lower-alcohol products that are popular.

Wineries are, however, becoming more aware of the potential of this market niche. That was evident at this year’s ProWein event in Germany (the world’s largest wine fair) where, for the first time, there was a dedicated area for Lo-No wines. Recent surveys of Australian wine demand in the United States found that around 30% of those in the trade, and around 40% of consumers of Australian wine there, had a strong interest in wines in the 7-9% alcohol range and at least a modest interest in zero-alcohol wine (Wine Opinions 2022, 2023). In response, a recent summit of Australian wine industry leaders acknowledged the need to create a mid-strength wine category (Winetitles

Media 2023). As well, the South Australian Government has invested $2 million in a new facility at the University of Adelaide that will allow winemakers to trial Lo-No products with as little as 150 litres of wine (Winetitles 2023).

This article seeks to draw lessons from the brewer experience that might be pertinent to the wine industry, particularly in Australia as it struggles to dispose of huge stocks of low-quality wine but also in New Zealand as it looks for ways to diversify its offerings. It happens that Australian brewers are leading the way globally in building various Lo-No beer categories. Indeed they have already contributed to the lowering of the nation’s alcohol consumption (Figure 1), so its trends are highlighted and compared with global trends. The article then concludes

by drawing out lessons and prospects for lower-alcohol wine.

WHY THE CONSUMER INTEREST IN LOWER-ALCOHOL BEVERAGES?

The Lo-No evolution in high-income countries is part of a broader consumer trend that is focused on healthier lifestyles, especially among Millennials and Generation Z. It is gradually becoming mainstream for at least two reasons. One is that, like the premiumisation trend, it does not require consumers to abandon the social role that beverages play. Secondly, it’s potentially a win-win financially for consumers and producers in jurisdictions where beverage excise taxes are higher for higher-alcohol products — such as in the UK where from 1 August 2023 taxes on all alcoholic drinks are now levied according to the strength, rather than type, of alcohol — or might become so. Beverage producers also may benefit insofar as health advocates lobbying for measures to reduce alcohol consumption acknowledge the emergence of lower-alcohol products.

PRODUCER RESPONSES TO THE DEMAND FOR LOWER-ALCOHOL BEERS

The demand for Lo-No beverages has prompted brewers to develop new technologies that are beginning to allow fullflavoured beers with lower-alcohol levels to be marketed, and at lower retail prices than their full-strength counterparts thanks to lower rates of excise tax for those beers.

While the categories of lower-alcohol beers have varied through time and across countries, a consensus seems to be emerging.

The following categories are the official Australian definitions:

No-alcohol: ≤1.15% of alcohol by volume (ABV)

Low-alcohol: >1.15% but ≤3% ABV

Mid-alcohol: >3% but ≤3.5% ABV

Full-strength: >3.5% AVB.

The alcohol content of ‘light’ beers, which began to emerge during the 1980s and which focused on calorie reduction (accomplished primarily by reducing the carbohydrate content but also by reducing the alcohol content), is usually >2% but ≤3.5% ABV, hence this category overlaps the low- and mid-strength beer categories.

Consumers looking for new varieties/styles are pleased with this development, as are those seeking lower-alcohol beverages for health, driver-safety and lifestyle reasons. So are some wine drinkers looking for substitutes for their preferred wines as global warming keeps raising the latter’s alcohol levels (Alston et al. 2015)? Many of those beer drinkers who previously sought out ‘light’ beers but were disappointed by the bland, watery taste of lots of them are more enthusiastic about this new alternative. Some abstainers of alcohol also may be willing to try new zero-alcohol beverages, although there has been little sign of that to date.

So far, brewers have been much quicker than distillers and winemakers in responding to this new Lo-No demand in fine-tuning or creating new techniques, in developing new products, and in mass-marketing them successfully. True, this development is still in its infancy, with the share of no-alcohol, lowalcohol and mid-strength beers, respectively,

accounting for just 2%, 0.7% and 1% of the volume of global beer sales in 2021, according to Plato Logic (2022). However, that 3.7% total is nearly double the 2.0% from a dozen years ago, hence the interest in the further growth potential of these categories.

AUSTRALIAN BREWERS LEADING THE WAY

Australia’s largest brewers have been among the leaders globally in developing and marketing low- and mid-strength categories. According to Plato Logic, those two categories’ combined share in Australia was 23% in the 1990s and 28% in the 2000s, when it was only 1% in the rest of the world, and by 2021 those shares were over 30% for Australia (all but one-tenth of it mid-strength) compared with 2% for the world (Table 1, see page 82). By contrast, when 2% of beer sales globally were zero alcohol in 2021, that category share in Australia was under 1%. Meanwhile, the share of full-strength beer in Australia’s total beer sales volume has fallen from 79% in the 1990s to 75% in the 2000s and to 69% by 2021 (row 1 of Table 1).

The Australian shares of no-alcohol, lowalcohol and mid-strength beers in national beer consumption are shown alongside those of other countries in Table 2 (see page 83). Of those countries, only New Zealand and the Netherlands have lower no-alcohol shares than Australia, only Germany and Sweden have had higher low-alcohol shares than Australia, and only Sweden has a substantial share like Australia (around one-quarter) of mid-strength beer.

The long-term trends for Australia since the mid-1980s are summarised in Figure 2 (see page 82). Overall annual sales volumes have been flat for more than three decades, and full-strength beer sales have been steadily declining. The combined share of low- plus mid-strength beers rose from 15% to 24% in the 1990s (when it was mostly ‘light’ beer) before plateauing over the 2000s and then rising again in the 2010s to 31%. By then the low-alcohol share had fallen to around 4% (with ‘light’ making up perhaps half that) while the mid-strength share rose above 25%.

Had the mix of beers in 2012-13 remained unchanged in the decade that followed instead of some substituting to lower-alcohol beers, an additional 3 million litres of alcohol (4% more) would have been drunk in 2021-22.

Figure 1. Volume of alcohol from beer, wine and spirits consumption per adult, Australia, 1961 to 2021 (litres of alcohol per person over 14 years).

a For Australia, No-alcohol means ≤1.15% of alcohol by volume (ABV); Low-alcohol is >1.15% but ≤3% ABV; mid-alcohol is >3% but ≤3.5% ABV; and full-strength is >3.5% AVB. The break between low- and mid-strength in Plato Logic data is 2.8%, not 3%.

b The full-strength share is 100 less the ABS’s L&M alc share less the No-alc share as estimated by Plato Logic, so it includes the Craft share.

c L&M tal is the share of total alcohol from beer that is consumed as low- or mid-strength beer, from ATO (2022).

Sources: Complied from ABS (2019), ATO (2022) and Plato Logic (2022).

LESSONS AND PROSPECTS FOR LOWER-ALCOHOL BEER AND WINE CONSUMPTION

IWSR expects the Lo-No category over all beverages — which is just 2% of the overall alcohol beverage market (and just 0.4% of the on-trade) — to grow by one-third (7% per year) between 2022 and 2026, and with the no-alcohol sub-category to account for 90% of that growth (Gilbert 2023). Beer is the clear leader in this category, with more than 3% of its global sales already Lo-No. An increasing number of brands are likely to launch more lower-alcohol variants. The world’s biggest beer brewer, for example, has set a goal of having at least one-fifth of its global beer output being lower-alcohol products by 2025 (https://www.ab-inbev.com/smart-drinking/ smart-drinking-goals/).

The prospects for successfully producing lower-alcohol wine continue to depend on the development of new, affordable technologies. Current technologies are such that it is more costly to generate lower-alcohol than regularalcohol wines and, even so, to date the former have not been able to match the perceived quality of the latter. Unless and until that changes through new innovations, this is likely

to remain a small niche part of wine markets. The fact that Australian consumers of beer have shown most interest in the mid-strength category of beer, and that consumers of Australian wine in the US also have expressed most interest on a mid-strength category (79%), suggests that should be the target zone for innovators.

Such innovation could be spurred though if excise duties were to become significantly

lower for lower-alcohol wines in major markets. Lower-alcohol beers are taxed only slightly less than full-strength beers in Australia, and the consumption tax on wine is related to its price, not its alcohol level.

This increasing preference for lower-alcohol beverages may well become another force for reforming that method of taxing Australian wine sales. The UK’s new excise duties are just £9.27 per litre of alcohol for products in the

Table 1. Shares of volume of beer consumption that is Low- and Mid-alcohol (L&M), No-alcohol,a and Craft, Australia and the world, 1990 to 2021 (%).

Figure 2. Volume of beer consumed as Full- and as Low- or Mid-strength beer, Australia, 1984-85 to 2021-22 (ML).

Table 2. Shares of no-alcohol, low-alcohol and mid-strengtha beers in total beer consumption, 1991 to 2018b (%).

REFERENCES

ABS (2019) Apparent Consumption of Alcohol, Australia, 2017-18. Catalogue No. 4307055001DO001. Canberra: Australian Bureau of Statistics.

Alston, J.M.; Fuller, K.; Lapsley, J.T.; Soleas, G. and Tumber, K. (2015) Splendide mendax: False label claims about the high and rising alcohol content of wine. Journal of Wine Economics 10(3):275-313.

Anderson, K. (2020) Evolving from a rum state: A comparative history of Australia’s alcohol consumption. Australian Journal of Agricultural and Resource Economics 64(3):724-749.

ATO (2022) Beer Clearance Summary Data

Canberra: Australian Taxation Office. Accessed 25 October 2022 at https://data.gov.au/data/dataset/ excise-data/resource/f2a889c3-8815-496e-8499e756288fdc06?inner_span=True

Dingwall, K. (2022) The no-alcohol drinks market surpassed $11 billion In 2022. Forbes, 23 December. https://www.forbes.com/sites/ katedingwall/2022/12/23/the-no-alcohol-drinksmarket-surpassed-11b-in-2022/?sh=57620c99689a

Gilbert, J. (2022) Low and no growth in the fast lane to 2026. Harpers Wine and Spirit Magazine, 16 December. https://harpers.co.uk/news/fullstory. php/aid/30973/Low___no_growth_in_the_fast_lane_ to_2026.html

HM Treasury (2023) The New Alcohol Duty System: Consultation London: HM Treasury and HM Revenue and Customs. https://www.gov.uk/guidance/ work-out-how-much-alcohol-duty-you-need-to-pay

Plato Logic (2022) World Beer Report 2022 Basingstoke UK: Plato Logic, October.

Winetitles Media (2023) Statement from the Australian wine sector CEO and managing director summit. https://winetitles.com.au/statement-from-theaustralian-wine-sector-ceo-and-managing-directorsummit/, 31 May.

Wine Opinions (2022) Wine Australia Consumer Survey Report. Adelaide: Wine Australia, November.

Wine Opinions (2023) Wine Australia Consumer Survey Report. Adelaide: Wine Australia, April.

a The division between low- and mid-strength beer in this table is 2.8% ABV.

b In the 3 years after 2018, the World ‘No-’ share rose to 1.7%, 1.9% and 2.0%, respectively, while the ‘Low-’ share stayed at 0.7%

Sources: Complied from Plato Logic (2022).

ABV range of 1.3% to 3.4%, compared with £21.01 for those in the 3.5% to 8.4% range and £28.50 for those in the 8.5% to 22% ABV range (HM Treasury 2023). Calsberg has signalled that it will lower its 3.8% beer

to 3.4%, following numerous other brewers with beers in the 3.5% to 4% ABV range (see https://www.inside.beer/news/detail/ uk-carlsberg-joins-other-breweries-to-loweralcohol-content/).

Winetitles (2023) World-first no and low alcohol investment led by South Australia. https://winetitles. com.au/world-first-no-and-low-alcohol-investmentled-by-south-australia/, Adelaide, 12 April.

ACKNOWLEDGEMENT

The author is grateful for financial support from Wine Australia, under Research Project UA1803-3-1, and from the University of Adelaide’s School of Agriculture, Food and Wine and its Faculty of Arts, Business, Law and Economics.

Bringing harmony to field blend white wines

Our latest tasting focussed on field-blend white wines of three or more varieties. It was also open to blends of three or more white varieties not necessarily sourced from the same vineyard as well as non-traditional white blends of two varieties. The producers of the top four wines of the tasting (see results page 88) have provided the following insights into our how their top blends came together.

HAHNDORF HILL 2022 BROTHER NATURE FIELD BLEND (RRP$39.00/BOTTLE)

bunches. Selective bunch-thinning and leaf plucking helps with this issue.

It is difficult to estimate the yields of the specific varieties, but the total vineyard block yields 9-10 tonnes per hectare. Within the different varieties, the yield rate will be much lower for varieties like Savagnin and Riesling, and higher for the Harslevelu and the Welschriesling.

Calling the harvest date is perhaps the single most critical factor for this wine. I like to pounce when some of the earlier ripening varieties are reasonably ripe, while the late varieties have just started to show the slightest hint of flavour development, but still retaining an excellent source of natural acidity, which is the backbone of this wine.

WINEMAKING

BACKGROUND

The inspiration for the inaugural vintage of this wine came one summer evening in 2016 on a rooftop bar in Vienna, while enjoying my first glass of a Vienna Gemischter Satz. This is the DAC wine of the Vienna wine region, which is famous for its white field blend wines. For seven years I stored the impression of this wine in my head, which is also the time it took for co-owner Marc Dobson and I to establish our Brother Nature block.

VITICULTURE

The Brother Nature vineyard block is on our Hahndorf Hill vineyard in the Adelaide Hills. Here we have, through grafting and interplanting, created an authentic field blend block where 12 different white varieties now co-exist in a single vineyard block.

There is some belief that part of the magic of these delicious field blend wines comes from having a diverse population of varieties with a diverse range of ripening characteristics, all co-grown, co-harvested and then co-fermented. There is also a belief that, due to the intimacy of this multicultural block, there will be biological

communication between the different varieties that will influence the growth and evolution of the vineyard.

Some of the vines were grafted onto 30-year-old Chardonnay own-rooted vines, while other vines were planted directly as young plants on varied rootstock.

The Brother Nature block is grown on a standard VSP trellis system, which has row widths of 2.5m while the vines are 1.2m apart. Shoot, bunch and fruit thinning is practised, but is only applied in part, or in total, to some of the 12 varieties, depending on their specific morphology.

The vineyard block is drip-irrigated from borehole water with the frequency of irrigation depending more on observed factors, such as the prevailing weather conditions and the growth pattern of the vines, rather than scientific evaluation of soil moisture content.

All our vineyard blocks at Hahndorf Hill have a central, permanent sward of phalaris grass.

The vines are barrel pruned in early winter, and then spur-pruned by hand in August.

Some of the varieties are particularly prone to botrytis because of the nature of their

This is not a wine that is blended in the winery. It is truly blended in the field. All the fruit is harvest simultaneously and processed together in the winery. I do not use any processes in the winery that will plump up the wine or mask the acid in any way, such as lees work, MLF or barrel fermentation. It is purely cool-fermented in stainless steel, and then racked as soon as possible with all the juicy, natural acidity intact.

MARKETING

This wine is marketed not as a fruit-salad of 12 different grape varieties but rather as an opportunity to divert attention away from any single variety and to instead focus on the terroir in the bottle. It is a powerful reflection of the slate and schist minerality of the top-soil in our block, the cool-climate nature of our region, the cultural practices that lead to the selection of the different grape varieties and the different proportion of these varieties and, finally, the chosen practices in the winery. It is being marketed via all available channels. The central panel of the Brother Nature label reflects the exact vineyard block where the 12 different grape varieties are grown together.

LARRY JACOBS OWNER/VITICULTURIST/ WINEMAKER HAHNDORF HILL ADELAIDE HILLS, SOUTH AUSTRALIA

Hahndorf Hill vigneron Larry Jacobs in his Brother Nature block during its development.

BACKGROUND

Chalmers has always called the Murray Darling region home, from the start of Bruce and Jenni’s winegrowing to the 30-plus-year story of the nursery and the importation of Italian varieties. Those vines were planted as our Mother Blocks, giving us the privilege of being the first Australian growers to tend scores of varieties. Since the first release Mother Block wines in 2021, Bruce and Jenni Chalmers along with daughters Kim and Tennille and Kim’s husband and winemaker Bart van Olphen have worked together every day to bring the Mother Block wines to life. The range is a celebration of the star performers, suitability and success stories of these varieties in their new home, the Murray Darling region.

VITICULTURE

The fruit for this wine is sourced from Chalmers Merbein Vineyard in the Murray Darling in Victoria. The vineyard achieved Sustainable Winegrowing Australia certification in 2023. Measuring approximately 35 hectares, it is home to every variety that our family has imported into Australia over the last 20 or more years and is the source block for millions of vines planted across Australia through our vine nursery, hence the name Mother Block for this range of wines.

All the vines in the source blocks are trained to a VSP trellis. There are also some commercial-sized blocks which are set up on a two-wire vertical trellis. The fruit for this wine can come from both vineyard set ups.

The Vermentino is clone VCR1 which was planted in 2010 on Ruggeri 140 rootstock; the Fiano is clone VCR3 which was planted in

2010 on Richter 110 rootstock; the Grechetto is clone VCR433, planted in 2017 on own roots; the Greco is clone VCR5, planted in 2010 on Ruggeri 140 on rootstock; the Glera is clone VCR101, planted in 2010 on Ruggeri 140; the Pinot Bianco is clone VCR5, planted in 2010 on Ruggeri 140; and the Pinot Grigio is clone VCR5, planted in 2010 on Ruggeri 140.

All the vines are planted at 2222 vines per hectare, with the VSP trellis rows shootthinned at the time of wire lifting.

Irrigation water is sourced from the Murray River and supplied via undervine drippers resting on the soil. Small amounts of water are applied daily when required. The average irrigation application is 4-5 megalitres per hectare per year of production (July-June).

Midrows are applied with composted cow manure and composted green waste. Beneficial fungi and seaweed applications are also carried out. Bare earth is maintained undervine to prioritise water going only to the vines.

The blocks on a two wire vertical trellis are hand spur pruned to 50 buds per vine, while hand pruning is carried out on the VSP blocks to 22 buds on each vine. We are considering mechanical pre-pruning followed by hand clean up on the two-wire vertical blocks.

The vines on the two-wire vertical trellis yield 22 tonnes per hectare, compared with 12 tonnes per hectare from the VSP blocks.

Timing of the co-harvest of the different grape varieties is determined after lots of tasting in the vineyards, in addition to the results from at least twice-a-week maturity testing — Baume, pH and TA.

CHALMERS 2022 MOTHER BLOCK (RRP$23.00/BOTTLE)

The final blend with respect to the varieties and percentages happen in the field based on flavour and blend balance. This part of the process is an absolute joy but a juggling act.

WINEMAKING

The fruit is machine harvested in the cool of the night, pressed within 5-8 hours of harvest to tank with soft pressings also going in; hard pressings are kept separate, settled, acid adjusted, then racked hard to then add back to the main tank. The tank is inoculated and fermented to dry. Once dry, the juice is sulfured, settled and racked off gross lees then packed up on fine lees for a short maturation of approximately six months.

From 2024, this wine will be naturally fermented.

MARKETING

The Mother Block range was launched in 2021. Its brand style is a nod to the history of the Chalmers family’s farming of the region and the cultural home of Chalmers. In our opinion it displays the huge potential of the Murray Darling region for producing these delicious, approachable, lifestyle wines made using climate-appropriate varieties. It is time to rethink this and other warm-hot, inland Australian GIs and what they can achieve, how they can taste and deliver and how viable the regions can be. These are fresh, clean, crisp wines where purity and intensity can be found in the glass, with the packaging used having the lightest footprint possible thanks to lightweight bottles, recycled paper labels, etc. The Mother Block range is currently sold domestically and in more than 25 states in the US.

TENNILLE CHALMERS DIRECTOR CHALMERS

MURRAY DARLING, VICTORIA

Harvesting of Chalmer’s Mother Block white varieties in 2023.

FABIANO MINCHELLA WINEMAKER BY FABIANO MCLAREN VALE SOUTH AUSTRALIA

BACKGROUND

The first and maybe only time I have seen this blend was during my time at Pipoli, Farnese, in Basilicata, Italy, back in 2013. While its wine is a commercial and different style, this blend pays homage to what I experienced over there. It was easy to fall in love with the Fiano component and it’s clear to see Australia is also quickly realising its love for the varietal. I always knew Greco would play a role in my winemaking as it is considered quite important and noble in the southern Italian region of Campania where it is known as Greco di Tufo. Given the climate is similar to McLaren Vale and the region is next door to my father’s homeland, it was easy for me to gravitate toward it. The Greco vines yielded their first crop in 2023. I originally imagined I’d make the blend three-quarters Greco and a quarter Fiano. While the blend was nice, the Fiano over powered the Greco character and, thus, 6.5% Fiano provided the balance between retaining the Greco character, while the Fiano adds some complexity and aids in the aromatic lift and crisp palate.

VITICULTURE

Both varieties are estate grown here in McLaren Vale. The Fiano component is towards Willunga at the foothills and grows on soils of brown/grey loam and alluvial fan clay. The site is north facing and rows run north-south. The vines were grafted in 2016 onto vines planted in 1996. They grow on a traditional single cordon, spur-pruned trellis system. The spacing between rows is 3 metres while the vine spacing is 1.8m. The vines are hand pruned with no mechanical pre pruning as we have learned to keep a rod to maintain crop levels. The vines are watered from our bore via drip irrigation and receive 10-12 hours per week, depending on the weather and season.

The Fiano yields an average 2.5-3.5 tonnes per acre and is always hand harvested.

While the vineyard set up and management of this block works well, my ideal scenario is to bring it in line with the winery estate vineyard where the Greco is located.

The Greco is grown in the heart of McLaren Vale on Tatachilla Road. The site is south facing

BY FABIANO 2023 GRECO FIANO (RRP$35.00/BOTTLE)

with rows running east-west. The soil is darker loam and richer. The vines are grafted onto Ruggeri 140 rootstock and are three years old. The 2023 vintage is their first crop. The trellis system is an Italian single arm Guyot, which is similar to cane pruning. Rows are 2.4m apart and vines 0.9m apart. We use foliage wires to promote vertical growth with shoot thinning and leaf plucking carried out on the southern side and, if necessary, we will fruit thin. Irrigation is sourced from reclaimed/recycled water with the vines receiving 10-12 hours per week.

The vines are pruned by hand. Greco has proven to be a very powerful vine with a thick canopy. However, even with the disease pressure of the 2023 season, the fruit held up well even when we were late to spraying and lost the adjacent Nero d’Avola. I assume the natural phenolics of the Greco played a part in its protection. Our inaugural crop from these vines yielded 2.3 tonnes per acre.

In harvesting both varieties, the qualities I am looking for are always based on taste and flavour. While I always monitor the technical analysis, I’ve noticed that these whites, especially the Fiano, are made to handle the heat and always come in with a low pH of 3.23.3 and 12-13 Baume.

In terms of soil and midrow management, the Fiano has a permanent sward with compost applied every few years. Being a new vineyard, the Greco has never had a cover crop, however, we used compost at planting to help them get established.

WINEMAKING

The winemaking was quite simple. The fruit was all hand harvested with the use of tannins pre-maceration for oxygen prevention. It was then destemmed and crushed. The rollers are usually open enough for the berries to split, however, for the Greco portion the rollers were left a bit open to minimise phenolic extraction.

Both parcels were separately fermented with blending happening pre-bottling. Both were pressed straight away. The free run and pressings went in together with the final cut made according to taste.

Both were fermented at a cool temperature of 11-12°C. The wines were racked clean soon

after fermentation. I did trial half the Greco in old neutral oak and the other half in stainless steel. Both were interesting and much more lively together. The oak added some interesting character to the palate, softening and filling, while the portion in stainless steel was quite lifted and aromatic while retaining minerality.

As previously mentioned, I am trying to pay homage to a style in Italy where the wine had little intervention in the winery and so no lees or skin contact nor new/toasty oak was used. The wine is released soon after bottling.

This is not a style that I see myself changing from a production perspective. The powerful aromas and full body don’t require any extra lees contact or extra oak. If the Greco vineyard matures and the fruit becomes higher in phenolics then I may need to look at some more time in neutral oak to soften the structure. Conversely, if the phenolics dumb down I could always play with skin contact or close the rollers more. It is Greco so some phenolics are necessary. Let’s see what happens!

MARKETING

The By Fabiano brand has been marketed as what we like to call, ‘New World Italian’. We are often surprised that this isn’t a genre that has been clearly defined as it has been a significant player in the New World for about 150 years. By Fabiano makes a point about merging Italian ingenuity in a land full of hidden potential and mystery that awaits us.

As a new brand, we launched our products exclusively in on-premise venues in Adelaide along with a few boutique off-premise venues. We have been partnering with venues that suit the brand and have a clientele that are interested in trying and chasing new wines.

BACKGROUND

The inspiration for this wine came from our desire to add more climate-appropriate white wines to our portfolio and decrease our dependency on red wines. It’s a partner for the Three Gardens GSM that sells via our cellar door, on-premise in particular and specialist retail channels. The inaugural vintage was 2017. Clairette Blanche was included in the blend from 2018 onwards at a maximum of 15%.

VITICULTURE

The fruit for this wine was sourced from rolling hills in southern Lyndoch comprising dark loam over white and yellow clay soils.

The approximate location of growers are Bethany (Clairette Blanche), Gomersal (Roussanne) and Vine Vale (Marsanne and Viognier).

The vines were planted in 2007 on Paulsen 1103 rootstocks. They are grown on a single cordon with a catch wire; rows are 2.5m apart and vines 1.5m apart.

Natural swards are cultivated in the mid row while compost is thrown under vine every three years to help maintain soil health.

The vines are mechanically pre-pruned followed by hand spur pruning to 50 buds/vine.

All the vines yield around 3 tonnes per acre.

The qualities we look for in each variety before harvest are as follows:

Viognier — quite ripe, 13.5-14.5 Baume, for strong peach/apricot stone fruit character

Marsanne/Roussanne — mid ripeness, 12-12.5 Baume, for better natural acidity, freshness, honeyed character and lower alcohol

Clairette — 11-12 Baume, for better natural acidity, freshness, honeyed character and lower alcohol

WINEMAKING

All grapes are machine harvested, destemmed and crushed. The fruit is pressed to tank with the heavy pressings returned after fining and cold settling. There is minimal skin contact.

Fermentation is carried out in stainless steel with 15-16% put in second-fill French oak for 6-7 months (usually just the Viognier goes into oak).

All varieties are left on lees for 6-7 months with occasional stirring.

The ferment temperature is controlled with the use of VinWizard at around 15-18°C.

MARKETING

The wine is sold in the cellar door, onpremise and specialist retail channels and

exported to Europe. Due to the relative unfamiliarity of the varieties and the blend, it’s a hand-sell and pitched as a food-friendly style — a $20 wine offering outstanding value for money and the quality is high. The 2021 vintage was pipped at the post for Best White Wine - Other Varieties or Blends trophy at the Barossa Wine Show, and the 2020 won the trophy for Best Dry White Blend in Show at the Royal Adelaide Wine Show.

PAUL

Do field blends have a natural edge?

By Sonya Logan

For centuries, Old World vignerons made single wines belnded from whatever varieties they had planted in their fields. Grapes would be picked at the same time and then co-fermented together to produce what we now refer to as a field blend wine.

While interplanted vineyards are increasingly rare, so too is the practice of co-fermentation, with most winemakers these days preferring to harvest different parcels of fruit grown in a particular vineyard block best suited to the production of that variety before harvesting them at their optimum, vinifying them separately, and later blending them to produce the finished product.

Field blend wines haven’t totally fallen out of favour though with the latest tasting by the Wine & Viticulture Journal putting white Australian examples under the spotlight. For comparison, our tasting was also open to blends of three or more white varieties not necessarily sourced from the same vineyard as well as non-traditional white blends of two varieties.

We received 25 entries of which over half were identified as field blends — made from a variety of grapes growing in the same vineyard and co-fermented together. All entries were tasted by our panellists in Master of Wine Phil Reedman, who has been involved in making field blend wines since around 2015; Michelle Heagney, head winemaker for Serafino Wines based in McLaren Vale; and former viticultural researcher and lecturer Peter Dry, who in his honorary role as emeritus fellow at the Australian Wine Research Institute contributes regularly to the Wine & Viticulture Journal’s Alternative Varieties column.

Reedman, Heagney and Dry were surprised to note from the snapshot of field blend wines in the tasting that a number had been made according to ‘natural’ or low intervention principles.

“What sticks out to me is that there is some conflation of field blend and low intervention/ natural wine which I think, at the very least, is a potential source of consumer confusion,” Reedman said. A consumer who bought one of the conventionally-made field blend wines in the tasting as well as one of the low intervention field blends would be greeted

with “two quite different experiences”, he noted. “Either can be appealing if that’s what you want,” Reedman said, “but if one of them is not what you want then you could be permanently put off what you believe to be a field blend white.

“People are obviously making field blends to suit quite a broad range of market niches [but] it risks consumer confusion,” Reedman added. “That does worry me given that I am involved in making field blends at the more

traditional end of the spectrum. What is a consumer to expect?”

“The percentage of field blends made in a natural style is quite high,” Heagney concurred in her observation of the field blends in the tasting. “Is that representative of the interpretation for a majority of producers of field blends wines?” she questioned.

The panellists said the tasting did not prove one way or the other that co-fermentation produced a better blended white than if each variety was vinified separately.

“One of my beliefs about co-fermenting is that you get a more complex array of flavours and aromatics than you do from blending post ferment with the same varieties. I don’t think this tasting can bear that out – prove it or disprove it. There are clearly some good wines that have been made by blending as well as by co-fermenting. It’s a bit inconclusive.”

“What this tasting does show is that the alternative varieties [featured in the wines of the tasting] are really exciting – there is some real excitement outside of those traditional varieties,” Reedman added.

The panel nominated the following wines as their top four, which included two conventionally-made field blends, one more akin to a low intervention field blend, and a non-traditional white blend: Hahndorf Hill 2022 Brother Nature Field Blend, Chalmers 2022 Mother Block White, By Fabiano 2023 Greco Fiano and Langmeil 2022 Three Gardens Viognier Marsanne Roussanne.

This issue’s tasting panellists were (from left) Master of Wine Phil Reedman; Peter Dry, emeritus fellow with the Australian Wine Research Institute; and Michelle Heagney, head winemaker with Serafino Wines.

HAHNDORF HILL 2022 BROTHER NATURE FIELD BLEND

Adelaide Hills, South Australia

Varieties: Harslevelu (18%), Welschrieling (16%), Riesling (13.5%), Sauvignon Blanc (10.5%), Chardonnay (9.5%), Gruner Veltliner (9.5%), Pinot Blanc (7%), Savagnin (6.5%), Chenin Blanc (5%), Muscat Blanc (1.5%), Gewurztraminer (1.5%), Muscadelle (1.5%)

Fruit source: Single vineyard block, Hahndorf Hill vineyard

12.0%v/v

RRP$39.00/bottle

Best of tasting: Light straw in colour. Fresh, vibrant, layered and interesting nose with characters of sherbet lemon, lemon rind/pith, lime, nettles and Chinese spice with some ripe peach in the background; slight H2S note. Nice balance of tight acid and fruit in the mouth; snow pea note evident. Long and grippy finish.

CHALMERS 2022 MOTHER BLOCK WHITE

Murray Darling, Victoria

Varieties: Vermentino (73%), Fiano (16%), Grechetto (5%), Greco (2%), Glera (2%), Pinot Bianco (1%), Pinot Grigio (1%)

Fruit source: Chalmers

Merbein Vineyard

12.3%v/v

RRP$23/bottle

Best of tasting: Bright, pale straw in colour. Gently aromatic nose that features notes of green apple, hay and lime along with a slight herbal character. The palate is clean, vibrant, well balanced and has nice weight. Notes of vanilla, red apple, citrus and apricot. Nice acid line and good length.

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BY FABIANO 2023 GRECO

FIANO

McLaren Vale, South Australia

Varieties: Greco (93.5%), Fiano (6.5%)

Fruit source: two separate vineyards in McLaren Vale

13.25%v/v

RRP30.00/bottle

Best of tasting: Deep golden in colour. An aromatic and complex nose of dried apricots, honey, florals and tropical fruits. Complex and well-balanced palate which has a nice textural element and features deep, intense flavours, including orange pith and pineapple. Good length with a clean finish. “A very good example of that style of winemaking – someone knows what they’re doing,” said one taster, adding “it would have considerable consumer appeal”.

LANGMEIL 2022 THREE GARDENS VIOGNIER MARSANNE

ROUSSANNE

Barossa Valley, South Australia

Varieties: Viognier (56.5%), Marsanne (16.2%), Roussanne (15.4%), Clairette (11.9%) 13.0%v/v

Fruit source: 3 separate growers near Bethany, Gomersal and Vine Vale, Barossa Valley RRP$20.00/bottle

Best of tasting: Mid pale gold in colour. Clean, medium intensity nose with notes of lemon, honey, citrus, spices and a slight herbal character. Medium to full-bodied, harmonious palate which is well balanced and has a nice acid line; ripe, albeit rather indistinct, fruit characters. Good persistence.

closures of excellence

2022

Eden Valley, South Australia

Varieties: Riesling (55%), Kerner(41%),Gewurztraminer(3%)

Fruit source: single vineyard, Eden Valley

21.3%v/v

RRP$30.00/bottle

Bright, light, pale straw in colour. Clean, fresh and lifted nose of honey, florals, crumpet, wheat and marmalade with a slight citrus fruit character. Slightly off dry palate is crisp, balanced and has a nice mousse; simple citrus characters evident. Acid is tight and linear. Lacks some complexity.

Yarra Valley

Varieties: Marsanne (75%), Arneis (25%)

Fruit source: Nagambie (Marsanne), Yarra Valley (Arneis) 13.5%v/v RRP$30.00/bottle

Deep bronze orange in colour. Clean and aromatic nose which is showing some development; acacia honey, almonds and rose soap notes along with an unusual herbal note. Palate is broad, somewhat simple and lacks some precision and brightness; slightly soapy. Clearly made to a certain style. “No apparent benefit in this blend of varieties,” said one taster.

BYRNE VINEYARDS 2022

SIDNEY WILCOX WHITE

FIELD BLEND

Riverland, South Australia

Varieties: 1/3 each of Chardonnay, Riesling, Semillon

Fruit source: Scott’s Creek Vineyard, Riverland 13.5%v/v RRP$25.00/bottle

Youthful colour of light straw. Nose is fresh, attractive and grapey but relatively simple and slightly sweet; lemon rind note apparent. One taster detected a slight attenuated/long ferment character. Palate is slightly sweet and fat but well balanced with some muscat and citrus notes and good texture. Finish is long and pure.

Riverland, South Australia

Varieties: 1/3 each of Semillon, Chardonnay, Riesling

Fruit source: Scott’s Creek

Vineyard, Riverland

13.5%v/v

RRP$25.00/bottle

Bright colour of light straw. Nose is fruity and flowery but somewhat neutral; characters of lime, apple and peach; slight ‘eggy’ aroma. Vibrant, fresh, delicate and well-balanced palate which has a nice line of acidity and features characters of ripe tropical fruit and grapefruit; slight sweet/sour note. Slightly hot finish. “An easy drinker,” noted one taster. “Palate is better than the aroma,” noted another.

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BYRNE VINEYARDS 2022 FLAVABOM FIELD WHITE

CHAFFEY BROS. WINE CO.

FUNKELPUNKT

JAUNT WINES 2022 SKINS

SILENT NOISE WINES 2022 MOFO BIANCO

McLaren Vale, South Australia

Varieties: Fiano (18%), Vermentino (35%), Zibibbo (24%), Greco (12%), Pinot Grigio (11%)

Fruit source: Riverland (Fiano, Vermentino, Zibibbo, Greco); Adelaide Hills (Pinot Grigio)

13.0%v/v

RRP$35.00/bottle

Bright, youthful colour of light straw. Appealing aromas of honey, quince fruit, apricot, peach and florals; slight grubby/petunia and waxy note. Somewhat broad palate with a corn kernel/oatmeal note. Hot alcoholic finish.

ATOM WINES 2022 ENTROPIC WHITE

Tasmania

Varieties: Gewurztraminer (50%), Pinot Gris (25%), Riesling (25%)

Fruit source: Tamar Valley (Gewurztraminer), Cradle Coast (Pinot Gris), Coal Valley (Riesling)

13.0%v/v

RRP$34.00/bottle

Slightly gold in colour suggesting some development. Aromatic and spicy bouquet with some slightly dusty development; lifted florals, including rose petal, apparent along with lychee and Turkish Delight notes. Palate is seductive, complex, wellbalanced and textured, featuring intense exotic fruits and spices. Some sweet characters apparent along with some rose petal. Great length. “Lacks some acidity but texture brings back the balance,” noted one taster.

Trusted

CORIOLE 2022 SANDALWOOD

McLaren Vale, South Australia Varieties: Piquepoul (50%), Grenache Gris (50%)

Fruit source: Coriole Sandalwood Vineyard, McLaren Flat

13.2%v/v

RRP$34.00/bottle

Deep straw in colour. Moderately intense nose of over-ripe citrus, mango, peach and hay; one taster thought there was an odd character about the nose which they thought might be VA/ethyl acetate. Short and simple palate with sour and carboard notes.

CHALMERS 2022 MONTEVECCHIO BIANCO

Murray Darling, Victoria

Varieties: Ribolla Gialla (50%), Vermentino (32%), Pecorino (9%), Moscato Giallo (3%), Malvasia Istriana (3%), Falanghina (3%)

Fruit source: Chalmers Heathcote Vineyard

12.3%v/v

RRP$25.00/bottle

Fresh and bright colour of light straw. Nose is slightly neutral with aromas of musk, lilac, vanilla oak, ginger beer and a hint of mint; perhaps a touch of H2S. Somewhat broad and simple palate with indistinct fruit characters; some good texture evident. Slightly acidic finish.

closures of excellence

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2022 DÜFTE PUNKT

Eden Valley, South Australia

Varieties: Riesling (33%), Gewürztraminer (33%), Kerner (29%), Pinot Gris (5%)

Fruit source: single vineyard, Eden Valley

12.8%v/v

RRP$28.00/bottle

Clear and bright colour of pale straw. Medium-intense aromatics on the nose which has notes of apricot and nectarine along with slight musk and herbal characters. Sherbet lemon on the palate which is somewhat simple and disjointed and slightly sweet; reminiscent of a German Riesling. Lacks some acidity. A bit short. “An easy drinker,” noted one taster.

EVANS EVANS WINES 2022

BAROSSA BIANCO

Barossa Valley, South Australia

Varieties: Pinot Gris (49%), Riesling (31%), Gewurztraminer (20%)

Fruit source: single vineyard, Eden Valley

13.6%v/v

RRP$28.00/bottle

Cloudy colour of deep straw/pale orange. Slightly closed nose of ginger, wet paper, spices, stewed fruit, cold tea and apricot juice. Palate is broad and somewhat clumsy with lots of texture. Panellists requested to open the second bottle and noted some variation between it and the first bottle, noting it was slightly fresher. “This wine is clearly pitched at a particular market niche and if that niche celebrates diversity within a case of wine, then this wine has met its mark,” noted one taster.

TSCHARKE WINES 2022

GIRL TALK

Barossa Valley, South Australia

Varieties: Savagnin (60%), Grenache Blanc (34%), Albariño (6%)

Fruit source: Marananga - Stone Well (Savagnin, Albariño), MaranangaGnadenfrei North Vineyard (Grenache Blanc)

12.5%v/v

RRP$20.00/bottle

Bright, light pale straw in colour. Somewhat simple and clean nose of ripe peach and lemon. One taster detected a metallic/ high sulfur note. Palate is rich, rounded and full-bodied, has good weight and acid drive. Lacks some flavour. Fruit is simple; lemon, lime and bitters character apparent.

2022 R/SM

McLaren Vale, South Australia

Varieties: Riesling (70%), Semillon (30%)

Fruit source: Saddlebags Hill Vineyard, Blewitt Springs

13.1%v/v

RRP$42.00/bottle

Pronounced colour of golden bronze. Nose shows evidence of VA; notes of toffee and musk evident. Palate is full and off dry and somewhat conflicted; honey and lemon characters and some bitterness. “Made to a particular style which has its market,” noted one taster.

closures of excellence

With our end-to-end, state of the art in-house manufacturing and production facility, Interpack can efficiently unite all your closure requirements under one roof.

BRASH HIGGINS WINE CO.

CHAFFEY BROS. WINE CO.

LITTLE FRANCES WINES

2022 ELEVENTH HOUSE SORELLA

Beechworth, Victoria

Varieties: Vermentino (40%), Pinot Gris (29%), Friulano (29%), Sauvignon Blanc (2%)

Fruit source: Michelini (Vermentino, Pinot Gris), Dalbosco (Friulano), Alpine Valleys; King Valley (Sauvignon Blanc)

12.0%v/v

RRP$28.00/bottle

Slightly golden in colour. Toasty, nutty and fresh nose, featuring notes of ginger and apricot. One taster thought the nose suggested slight oxidation. Palate is full, rounded and well-balanced with a core of sweet, ripe fruit. Good acidity and persistence with some complexity. “A subtle, understated wine but all the elements added up,” noted one taster.

FLOWSTONE WINES

2022 MOONMILK BY FLOWSTONE

Margaret River, Western Australia

Varieties: Pinot Gris (32%), Viognier (25%), Gewurztraminer (22%), Savagnin (16%), Sauvignon Blanc (5%)

Fruit source: Margaret River

12.5%v/v RRP$22.00/bottle

Golden straw in colour. Lifted tropical fruit characters on the nose are hidden behind a lot of oak, albeit nice oak; slight lantana note. Palate is a fullblown, richer style but is in check; honey and apricot characters evident. Finishes with texture. Slightly hot finish. “Lacks some shape,” said one taster.

Refined

At Interpack, our state of the art in-house manufacturing facility combined with our expert craftsmen, produce innovative solutions for all your closures. From exquisite muselets through to crown seals, beverage and wine closures.

MT BERA VINEYARDS

2022 DREAM CATCHER

VINEYARD FIELD BLEND

WHITE

Adelaide Hills, South Australia

Varieties: Sauvignon Blanc, Chardonnay, Riesling, Viogner 12.7%v/v RRP$25.00/bottle

Bright, light straw in colour. Floral characters on the nose, including rose petal, along with oyster juice and chicken salt; possibly oxidised. Tight grippy acid.

BROKENWOOD WINES

2022 TWENTY70 WHITE BLEND

Hunter Valley, New South Wales

Varieties: Verdelho (42.05%), Semillon (33.73%), Chardonnay (24.22%)

Fruit source: Oakey Creek

Vineyard, Hunter Valley

14.0%v/v

RRP$57.00/bottle

Deep gold in colour. Medium intensity nose which is oxidised and therefore only slightly fruity; characters of Chinese spices and broth. Palate lacks flavour and has a wet cardboard note to it. Slightly medicinal finish.

closures of excellence

RAHONA VALLEY

2021 TRINITY

Mornington Peninsula, Victoria

Varieties: Pinot Gris (76%), Riesling (17%), Gewurztraminer (7%) a Fruit source: Mornington Peninsula

13.0%v/v

RRP$35.00/bottle

Bright light straw in colour. Lifted fresh apricot on the clean and somewhat neutral nose along with some pretty florals and a slight herbal note.

Mouthfilling, full and balanced palate which is just off-dry; notes of acacia honey and florals also apparent along with a touch of bitterness. Hot finish. “A nice drink,” noted one taster. “Lacks fruit,” noted another.

2021 TWB-TOOLLEEN

WHITE BLEND

Heathcote, Victoria

Varieties: Roussanne (49%), Marsanne (35%), Grenache Gris (16%)

Fruit source: Tellurian Organic Vineyard

14.2%v/v

RRP$40.00/bottle

Slightly golden in colour. Stone fruits, vanillin, toasty oak and a hint of florals on the nose. One taster detected a stuck ferment character. Palate is quite full bodied and luscious and has a nice texture but it falls away. Slightly sweet character. Lacks freshness. Honeyed finish.

GRAZIA

Heathcote, Victoria

Varieties: Friulano (26%), Malvasia d’Istria (24%), Pinot Bianco (44%), Picolit (6%)

Fruit source: Mount Buff Vineyard, Alpine Valleys

13.0%v/v

RRP$34.00/bottle

Bright gold in colour. Chardonnay-like nose with funky, nutty notes suggesting the influence of malolactic fermentation or a wild ferment in barrel. One taster noted an aroma of burnt rubber. Palate is broad, buttery and toasty, somewhat one-dimensional and lacks definition and acid. Finishes short.

GRAZIA

Heathcote, Victoria

Varieties: Pinot Bianco, Friulano, Malvasia d’Istria, Picolit

Fruit source: Mount Buff

Vineyard, Alpine Valleys

13.5%v/v RRP$38.00/bottle

Bright, pronounced gold in colour. Complex, barrelfermented aromatics on the somewhat developed nose as well as toffee, burnt pineapple, sweet marmalade, butter and florals. One taster thought the nose suggested the influence of botrytis. Palate has lost most of its fruit, leaving honeyed and toasty notes. Good, well-balanced acid. Reasonable length. Slightly dirty finish initially. “May have been better when younger,” noted one taster.

TRENTHAM ESTATE

2021 52 & CLOUDY BY TRENTHAM

ESTATE

Murray Darling, New South Wales

Varieties: Viognier (22.17%), Semillon (21.03%), Verdejo (20.21%), Sauvignon Blanc (19.51%), White Frontignac (11.60%), Saperavi (3.34%), Fiano (1.78%), Cabernet

Sauvignon (0.21%) and Tannat (0.15%)

Fruit source: single vineyard, Murray Darling

13.0%v/v

RRP$25.00/bottle

Pale, bright, vivid red in colour. Nose is somewhat subdued and faintly floral with a red apple note. Nice umami and raspberry characters on the savoury palate, which is a bit broad but has interest. Crisp acid. “If you tasted this wine without looking you’d think it was a white wine,” observed one taster.

Awarded

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