Winemaker's Quarterly Vol. 2 Issue 3

VOL. 2 / ISSUE 3

SPRING/SUMMER 2016

WINEMAKER’S Q UA RT E R LY PRESENTED BY ETS LABS

- F E AT U R E The Myths Behind Native Yeast -TECHNOLOGY Quality Control at ETS - N E W AT E T S Year-Round Courier Service

TABLE OF CONTENTS VOL. 2 ISSUE 3

Spring/Summer 2016

4

Questions and Answers

6

Quality Control at ETS

9

Native Yeasts & Production

15

Courier Service

Editorial Team:

Owners: Gordon Burns, Marjorie Burns Creative Direction: Evin Morrison

Photography: Kingsley Burns, Evin Morrison

Editorial Contributors: Rich DeScenzo, Steve Price, Eric Herve, Gordon Burns, Marjorie Burns

Questions or feedback? Send us a note: editor@etslabs.com

W

e've been hard at work gearing up for harvest. With new research about native fermentations, new locations and an expanded courier service for our Willamette Valley location, we're here to help you get the most out of Harvest 2016.

We're proud to announce that our Paso Robles lab gained ISOaccreditation earlier this summer, a distinction we hold at all our locations. Learn more about what goes into the accreditation process, and why it matters on page 6.

As always, we've answered some of your most frequent questions

on page 5. In addition to pre-shipment integrity and oak aroma, learn how to gain access to old reports and control who has access to your account on our website – it's the perfect time to review your settings and add your new team members!

Don't miss our feature article on new research that is debunking some of the common myths surrounding native yeast fermentations. (Page 9) If you caught the seminar with Dr. Rich DeScenzo, this is your chance to take a closer look at the supporting data.

We hope you enjoy the rest of your summer and that you're ready for yet another amazing harvest! We look forward to working with you to make your 2016 vintage the best one yet.

Gordon Burns (707) 302-1211 gburns@etslabs.com

Marjorie Burns (707) 302-1222 mburns@etslabs.com

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QUESTIONS ANSWERS We have compiled some of the most frequently asked questions from our clients before harvest and answered them for you here.

Q: A:

How can I minimize my risk when buying or selling wine?

There are inherent risks when wine is bought and sold. It is not unusual for claims to be filed alleging changes in a wine between the initial tasting and the final receipt of the wine. Common complaints are damage that occurred during shipment, claims regarding the integrity of a wine, microbial spoilage, or sulfide off aromas.

Often a buyer will question if a wine received in shipment is the same wine they agreed to purchase. There are certain parameters in wine that used together provide a unique fingerprint of the wine. Some of these parameters are difficult to manipulate, such as wine density and levels of copper, iron, or calcium. A pre-purchase analysis of the wine can be used to generate a chemical “fingerprint” of the wine – in situations where integrity is questioned, the initial analytical data can be used for comparison against the analytical results obtained on the final wine shipment.

It's important to plan ahead and take appropriate samples before transporting the wine – without an undamaged “control” wine from the same lot for comparison, it is usually difficult to provide conclusive evidence that damage occurred during shipment.

4 |WINEMAKER’S QUARTERLY

Q: A:

Why is there so much variation in oak aromas?

Major sources of variation are the oak itself, growing conditions, and cooperage practices. These variations interact with each other, forming many potential aroma profiles.

Oak species differ greatly. The French pedunculate oak (Quercus pedunculata aka Q. robur) is known for its relatively faint aroma potential compared to French sessile oak (Q. sessilis aka Q. petraea). American white oak (Q. alba) can have a strong, distinctive aroma that is sometimes considered overpowering in certain wines. Oregon white oak (Q. garryana) seems to have more similarities to the French oaks than to American white oak.

Geographic origin is linked to botanic species, but different species frequently grow in the same forests, and hybridization does occur. Growing conditions, age and genetic variation of individual trees can strongly affect wood structure and composition, with even a stave’s position within the tree trunk influencing its aroma composition.

Stave seasoning and drying are important. Kiln drying is likely to result in a different aroma character than air drying. Air drying conditions (time spent in open air and humidity level) also have a significant influence on wood aroma potential.

The cooperage process adds a considerable layer of variability. Definitions of “light” to “heavy” toasts are subjective and vary among coopers. Difficulty in controlling toasting levels creates barrel-to-barrel variation. In addition, stave to stave variation also occurs in the same barrel as some staves may toast more rapidly than others.

ETSLABS.COM Looking for a copy of an old lab report?

Want to add someone to your account?

Anyone who receives emailed reports or invoices can view and search lab results online.

You can control who has access, and add new team members, using the account settings button on your company’s dashboard:

If you have never logged in before, or forgot your password, just click the “request password” button on the login page.

For step-by-step instructions, visit help.etslabs.com and search for “inviting new user"

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CULTURE OF QUALITY Maintaining ISO accreditation has helped us build a strong culture of quality throughout ETS.

While we recently celebrated the grand opening of our newest lab in Paso Robles, we’re also celebrating an even more significant achievement: our newest location also earned its ISO accreditation, passing the initial quality audit with flying colors.

What does ISO accreditation mean?

The ISO 17025 accreditation, which ETS holds at all 5 of our locations, not only allows winemakers to verify that a laboratory has thorough quality management systems and controls in place, but it also evaluates the lab’s competency to produce accurate results.

We are excited that our new Paso Robles facility will be the first ISO-accredited wine lab in the Central Coast region, and we look forward to supporting the local community with reliable analyses that winemakers can count on, every time.

Our experience with ISO accreditation dates back to 1997, when ETS became the first ISOaccredited independent laboratory to serve the wine industry. Since then, we’ve expanded to support other growing wine regions, while still keeping our focus on quality.

Why does accreditation matter?

It can be tempting to think of lab results as nothing more than numbers – a six always looks like a six no matter who reports it. But in reality, not all numbers are created equal.

In order for lab results to have any value to a winemaker, they need to be unquestionably reliable and accurate.

It usually takes only one expensive problem or product loss to learn the value of reliable and accurate analysis. Whether making accurate additions, verifying a sterile filtration, or looking for bacterial contamination before bottling, it’s critical that winemakers have full confidence in the information that backs their production decisions.

The cost of risk management pales in comparison to expensive remediation treatments, or writing off unsellable wproduct.

In this case, cutting cost means sacrificing quality/reliability.

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WINEMAKER’S QUARTERLY

Good winemaking will always require a successful blend of art and science, but having accurate data supports the winemaker ' s intuition and helps them ask the right questions.

This standard specifically evaluates the technical competence of a laboratory, and requires internal and external audits of methods, systems, training and results. It is different from most ISO certifications (like the common ISO 9001) in that it measures performance and competency, not just record-keeping. Laboratories accredited to ISO 17025 are also required to have regular re-examinations to check that they are maintaining their standards of technical expertise.

The scope of accreditation matters.

The ISO accreditation only covers the specific analyses listed in a lab’s Scope of Accreditation.

The Scope lists the specific tests that have been approved by the specialist technical assessor as part of the accreditation process. During the ISO audit, the assessor examines each of these analyses in detail, evaluating the validity of the test method, traceability of measurements, technical competence of staff, and quality assurance of test data, among other criteria.

Our scopes of accreditation cover over 40 analyses using 17 different technologies - the most of any independent wine lab in the country.

ETSLABS.COM|

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8 |WINEMAKER’S QUARTERLY

THE

NATIVES RESTLESS ARE

Through The Looking Glass: What Really Happens In Your Fermentations

In the winemaking process, yeast populations can be diverse and dynamic, both before and during the primary fermentation.

Identifying the diversity present in the yeast population and the changes that occur during fermentation provide a tool for winemakers to better understand what is occurring within the yeast population throughout the fermentation process.

ETS Laboratories utilizes a method of DNA fingerprinting known as Multi-Locus Variable Copy Number Tandem Repeat Analysis (MLVA), to discriminate between closely related strains of indigenous and commercial Saccharomyces cerevisiae. The MLVA method detects differences in the number of tandem repeat DNA sequences in individual strains. The genomes of the target organisms contain many regions with tandem repeat DNA sequences that are amplified using a polymerase chain reaction (PCR). The resulting length of the amplified piece of DNA is directly related to the number of tandem repeat sequences present at a particular location in an individual microbial strain.

forming a unique DNA fingerprint for individual strains of S. cerevisiae.

Clients use this technology to monitor yeast populations in both inoculated and non-inoculated fermentations. Analyzing fermentations at the beginning, middle and end time points provides a view of the changes occurring in the non-Saccharomyces and Saccharomyces populations throughout the fermentation.

This analysis can be used to monitor native fermentations as well as to characterize the efficiency of commercial strains inoculated into musts. The ability to monitor the yeast population during fermentation ensures that process decisions affecting wine production are made based on actual data from the winery’s fermentations. Decisions regarding the selection of strains can be based on observations of their ability to perform in a clients’ specific wine style. The analysis can also be used as a quality control tool to verify that desired strains are dominating the individual fermentations, resulting in more consistent fermentations.

A multi-year study was conducted on non-inoculated fermentations using grapes from six vineyards at six separate wineries. Grapes from three vineyards were fermented in three different wineries.

Grapes from three additional vineyards were fermented in the other three wineries. Grape samples from the vineyards were analyzed by VNTR to determine which yeast species/strains were present in the vineyards. Fermentation samples were submitted from the wineries for VNTR analysis at the beginning, mid, and end of fermentation, in order to monitor changes in yeast population structure within the individual fermentations.

A single location may contain enough variation to distinguish between several strains, but multiple locations provide the potential to distinguish between an unlimited number of strains. The ETS MLVA for S. cerevisiae analyzes 5 unique locations, enabling winemakers to detect and identify commercial strains of S. cerevisiae, as well as identify non-commercial strains. The five locations were selected after screening 23 published loci to determine which were most effective for creating a multiplex assay. ETS utilizes a 6-plex polymerase chain reaction amplification process to amplify highly variable regions in the yeast genome. This involves amplifying 5 target sequences specific to S. cerevisiae and one universal target We've presented the results of the study as answers to six that can distinguish between most species of yeast. Capillary common questions we regularly hear from winemakers: electrophoresis is used to separate the amplified fragments by size, >> continue ETSLABS.COM|

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1) Is it possible to have a fermentation driven by indigenous Saccharomyces cerevisiae yeast?

Analysis of the 18 fermentations in 2015 indicates at least four of the fermentations did not contain any yeast strains present in our library of commercial Saccharomyces cerevisiae strains (Table 2). These include the fermentations from Winery F, where no S. cerevisiae strains similar to commercial strains were recovered.

However, the fermentations from Winery A were dominated by a single strain of yeast that had the same MLVA profile as the Lallemand strain Enoferm Syrah.

This commercial yeast strain was used Total Strains

Similar to Commercial

in this facility during the 2015 vintage.

Other wineries were a mix of putative native strains only or a combination of putative native strains and commercial strains. The fermentations from Winery C contained only putative native strains at the mid fermentation point, but finished with commercial strains present. This type of shift in yeast population profile has been observed in many non-inoculated fermentations, suggesting the commercial yeast strains are more competitive as the ethanol level increases.

Putative Native

Winery A

Total Strains

Similar to Commercial

The results from seven years of analyzing client samples indicate that it is possible to have non-inoculated fermentations driven by indigenous strains of S. cerevisiae. The use of commercial yeast in a facility will decrease the likelihood of indigenous yeast strains dominating the noninoculated fermentations. Non-inoculated fermentations driven by indigenous strains in a facility using commercial yeast requires a fastidious winery sanitation program.

Putative Native

Winery C

Total Strains

Similar to Commercial

Putative Native

Winery F

Vinyard 1 mid-ferment

2

1

1

Vinyard 1 mid-ferment

6

0

6

Vinyard 4 mid-ferment

9

0

9

Vinyard 1 end ferment

1

1

0

Vinyard 1 end ferment

7

2

5

Vinyard 4 end ferment

7

0

7

Vinyard 2 mid-ferment

1

1

0

Vinyard 2 mid -ferment

11

0

11

Vinyard 5 mid-ferment

10

0

10

Vinyard 2 end ferment

1

1

0

Vinyard 2 end ferment

9

2

8

Vinyard 5 end ferment

8

0

8

Vinyard 3 mid-ferment

1

1

0

Vinyard 3 mid-ferment

11

0

11

Vinyard 6 mid-ferment

7

0

7

Vinyard 3 end ferment

1

1

0

Vinyard 3 end ferment

10

2

8

Vinyard 6 end ferment

Table 1. Number of Saccharomyces cerevisiae strains observed at mid and end fermentation time points for the trial. S. cerevisiae strains whose MLVA profiles did not match any of the 140 strains in our library of commercial S. cerevisiae strains were categorized as putative native strains.

2) Do indigenous Saccharomyces cerevisiae strains from the vineyard persist through the fermentation?

Observations from both vintages indicate Saccharomyces cerevisiae strains from the vineyard can be recovered from mid and end stage winery fermentations. Analysis indicates that yeast strains observed in the vineyard were observed in six of 18

winery fermentations in 2014 and eight of 18 winery fermentations in 2015. In 2014, the percent of vineyard yeast strains present at the end of fermentation ranged from 0-75%, and in 2015, that number ranged from 0-25%. Although vineyard

yeast can be found in the fermentations, it is unusual for them to dominate the fermentation. Examples of yeast strains observed in the vineyard persisting in the fermentations can be seen in Figure 1.

Figure 1. Saccharomyces cerevisiae strains observed in the Vineyard 2 cluster fermentation and recovered from both mid and end of fermentation with those grapes at Winery B.

10 | WINEMAKER’S QUARTERLY

3) Are vineyard yeast strains, including Saccharomyces cerevisiae and non-Saccharomyces, the same from vintage to vintage?

In 2014, grapes were submitted from 5 vineyards and three of the samples contained Saccharomyces cerevisiae with a total of 29 putative native strains. In 2015, grapes were submitted from all 6 vineyards and S. cerevisiae was observed in all 6 vineyard samples with a total of 31 putative native strains observed.

Comparative analysis was done on the 60 strains observed over the two vintages. A single strain was observed in both vintages from Vineyard 6.

Differences were also observed in the non-Saccharomyces yeast strains between the 2014 and 2015 vintages (Figure 2).

Generally speaking, Hanseniaspora spp.

are the most prevalent non-Saccharomyces yeast observed on the grapes. However, in 2014, the most prevalent yeast in Vineyard 2 was a Picha spp and in 2015 it was a Kazachstania spp.

This data is only based on 2 years of analysis, but it suggests the vineyard yeast population is dynamic vintage to vintage.

Figure 2. Vineyard non-Saccharomyces yeast strains observed in the 2014 and 2015 vintages >> continue ETSLABS.COM |

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4) What yeast strains dominate non-inoculated fermentations in wineries that have used commercial (ADY) Saccharomyces cerevisiae yeast in the past or currently?

All of the wineries that participated in the study have used commercial yeast strains in past vintages and most facilities used them in the 2014 and 2015 vintages.

Commercial Saccharomyces cerevisiae strains are selected for many traits, but competiveness is a major factor. The results in Table 1 indicate that commercial yeast strains are often present in non-inoculated fermentations as evident in Wineries A and C. An extreme example of this

occurred in the fermentations conducted at Winery A. All three of the non-inoculated fermentations were dominated by the commercial Lallemand strain Enoferm Syrah (Figure 3). This commercial strain was used in the winery during the 2015 vintage. Observations on numerous noninoculated fermentations indicate that commercial yeast strains tend to show up later in the fermentation as alcohol levels increase.

The majority of non-inoculated fermentations had a higher number of putative indigenous strains than commercial strains of S. cerevisiae. Overall, good winery sanitation and awareness of the potential for cross contamination should minimize the appearance of commercial strains in non-inoculated fermentations.

Figure 3. Fermentations done at Winery A using grapes from Vineyards 1, 2, and 3. The non-inoculated fermentations were dominated by the commercial yeast strains Lalvin Enoferm Syrah at the mid and end time points.

12 | WINEMAKER’S QUARTERLY

5) Do yeast from the vineyard or “resident/house� yeast strains in the winery drive non-inoculated fermentations?

In order to determine the origin of the yeast driving these non-inoculated fermentations, comparative analyses were conducted. The analyses looked at similarities between fermentations using grapes from the same vineyard at different wineries (Same Vineyard Different Winery) and between fermentations using grapes from different vineyards at the same winery (Same Winery Different Vineyard). The expectation would be that vineyard yeast dominance would result in similarities The resident between the strains appear fermentations using to be a mix of the same grapes but at different wineries. commercial Likewise, resident strains used yeast dominance in the winery would result in more as well as non- similarities between commercial fermentations using different grapes, but strain. at the same winery.

More similarity was observed between yeast populations in fermentations at the same winery but using grapes from different vineyards (Figure 4).

Less similarity was observed between fermentations using the same grapes, but at different wineries. The results suggest the resident yeast in a winery were more prevalent in the fermentations than yeast originating from the vineyard. The majority of the similarity observed in fermentations at different wineries, but

using grapes from the same vineyard, was due to the presence of similar commercial strains at both facilities.

The results from two years of analysis indicate that although vineyard strains can be recovered from non-inoculated winery

Same Vineyard Different Winery

Similar

Different

fermentations, the fermentations appear to be driven by yeast strains resident in the winery. The resident strains appear to be a mix of commercial strains used in the winery as well as non-commercial strain.

Same Winery Different Vineyard

Similar

Different

Figure 4. Comparison of yeast populations recovered from fermentations in 2014. Yeast populations were compared between fermentations using grapes from the same vineyard, but done at different wineries, and between fermentations at the same winey, but using grapes from different vineyards. Green color indicates similarity between yeast populations present in the two fermentations and red color indicates no similarity.

>> continue

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6) Is the strain used for inoculation the only strain, or dominant strain present in the fermentation?

Fermentations inoculated with commercial strains of Saccharomyces cerevisiae were analyzed to determine if the inoculated strain dominated the fermentations as expected. In most cases, fermentations inoculated with commercial strains are dominated by those strains. There are

always exceptions, usually resulting from improper rehydration of the yeast and/or insufficient yeast added to the fermentation. In some cases, different yeast population structures are observed in similar fermentations (Figure 6). In this analysis, the wine in the two tanks tasted

different and although they were supposed to be inoculated the same way, with the same starting juice, there were differences in the population structure at the mid and end fermentation time points.

Figure 6. Two commercial fermentations inoculated with CY3079. The tanks contained the same juice and were inoculated following the standard practice at the winery. The target Commercial Yeast (TCY) used for these two tank inoculations was CY3079. An unknown Saccharomyces cerevisiae (USCY) strain and a non-target commercial yeast strain (NTCY) were recovered from both tanks.

In general, when commercial strains are used according to the manufacturer’s instructions, the strains implant well and dominate the fermentation.

Sometimes, the inoculated commercial yeast strain is not recovered from the fermentation to which it was added.

Figure 7 illustrates three fermentations, one non-inoculated and two inoculated with commercial strains. Neither of the commercial strains used for inoculation were recovered at the mid and end time points in those fermentations. The yeast population profiles in the inoculated fermentations were diverse and similar

to a non-inoculated fermentation from the same juice. Discussion with the student responsible for inoculating the fermentations indicated he couldn’t find a thermometer for measuring rehydration water temperature. The student decided to use the “hottest” water possible.

Yeast producers provide information on the applicability of various strains for particular musts/wine styles and detailed information on best practice

Figure 7. Yeast population profiles at the end of fermentation for a senior project with non-inoculated and inoculated fermentations

14 | WINEMAKER’S QUARTERLY

for rehydration and application rate for individual strains. In general, when commercial strains are used according to the manufacturer’s instructions, the strains implant well and dominate the fermentation. In situations where less than optimal conditions are used with a commercial strain, competitive resident yeast strains can dominate the fermentation rather than the targeted commercial strain used for inoculation.

PICK UP & D E L I V E R Submitting samples is easier than ever with our dropboxes, courier service, and more.

A

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N EW L O CA L CAPA B I L I T I E S

CONVENIENT DROPBOXES

COURIER SE RVICE

We're bringing some of our advanced tools to your doorstep with new equipment and capabilities at our satellite labs. Clients in Paso Robles and Newberg can benefit from fast local phenolic analysis starting this harvest.

24-hour secure dropboxes to fit your busy schedule are available for use after hours.

Please call your closest ETS location for the access code.

Our complimentary year-round courier service has expanded to cover more of the Willamette Valley, and will be coming soon to Paso Robles! Visit our website to schedule your next pickup.

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