Sector | Brewhouse How two German breweries are leveraging brewhouse technology from Ziemann

IMPROVE THE PROCESS

INNOVATION IN THE FIELD OF BREWHOUSE TECHNOLOGY IS HELPING BREWERIES ACROSS EUROPE TAKE THEIR OPERATION TO THE NEXT LEVEL. IN THIS ARTICLE, DR.-ING. VERENA BLOMENHOFE LOOKS AT HOW ZIEMANN SYSTEMS ARE BEING LEVERAGED BY TWO GERMAN BREWERIES TO IMPROVE THE EFFICIENCIES AND EFFECTIVENESS OF THE BREWING PROCESS.

With Omnium, the brewhouse tasks are divided into subprocesses, which are treated individually and, by subsequently combining partial flows, finally completed in an optimal way. As a result, significantly shorter process times and higher raw material yields can be achieved. The process has a positive impact on the quality parameters of the wort. In addition, the fermentation can be accelerated, leading to increased brewhouse and cellar capacities. As part of the development of Omnium, the brewhouse tasks were divided into their respective subprocesses and were improved individually. Finally, these subprocesses were reunited at the optimum time to an overall solution. This innovative brewing process is based on the principle of an advantageous combination of individually improved subprocesses. The core component and centrepiece of Omnium is Nessie.

It allows almost any batch size and almost complete freedom in the type and composition of the malt mixture. It is not just about the recipes. While the classic brewery must rely on special barley that has been bred for optimal usability in current brewhouses, all types of grain can be used in the Omnium brewhouse – as it was the case in the founding years of Ziemann. Comparable to a piano on which only eight notes were to be played, but now the entire instrument can be used. Never before has it been possible to process such a high proportion of raw materials in a lautering system. Nessie paves the way for the elimination of the time-limiting process step of lautering. The mash transfer time corresponds to the lautering time and the lautering is basically a transfer step of the wort boiling and can therefore be carried out continuously. With Nessie by Ziemann, the identical plant can process strongly varying original extract contents (up to 32 °P), depending on the variety, as well as different starch sources or smallest batch sizes. With the effective counterflow extraction, Nessie always achieves high yields with the usual sparging water quantities of 2.5 to 3.5 l/kg malt. Process times can be reduced by up to 30 %. The spent grains are discharged continuously after passing the fourth module with a residual moisture of < 78 %. Overall, the system produces more particle-rich and more turbid worts due to the dynamic filtration principle, the viscosity of which plays no role for the separation.

The separate vessel Aladin by Ziemann succeeds in extracting partial worts for an optimized malt utilization. Between one and two percent of the lautering

volume is initially collected into Aladin by Ziemann as enzyme extract for the post-saccharification of wort. The system essentially consists of an insulated, cylindro-conical stainless steel tank. The malt alpha-amylase, buffered in this tank at approx. 72 °C, ensures a subsequent complete saccharification of the boiled wort. For dosing the enzyme extract, the wort is cooled down to 83 to 90 °C.

While the innovative Janus by Ziemann, a hop isomerization vessel with about 40 % of the beer wort, helps the brewer to effortlessly and flexibly give the beer the required hop aroma and bitterness, 60 % of the beer wort boil in parallel in the wort boiling process. This means that the process of wort boiling and the hop isomerization are decoupled process steps in the Omnium brewing process. Modules 3 and 4 are suitable for the hop isomerization due to the lower bitter substance losses resulting from the reduced protein load. The low original extract of about 2 °Plato and the higher pH value of this wort fraction have a positive effect on the conversion of the hop bitter substances. The dosing possibilities of the

isomerized wort of the Janus are manifold and cover both the brewhouse and the sterile hop addition in the cold block.

By using the separate hop isomerization vessel Janus, the tasks within the wort boiling process by means of the internal boiler Shark by Ziemann or the external boiler Dolphin by Ziemann are the same as before, only the isomerization is no longer considered in this process step. Both processes can be optimized separately. It is possible to transfer hop trub from the Janus into the wort kettle. This supports the protein precipitation by the polyphenols of the hops. After the boiling process, the wort is cooled down to 83 to 90 °C. At this temperature, the first wort extract Aladin is dosed. In the whirlpool Wortex by Ziemann, the hot trub is separated, which consists of about 80 % water, a mixture of insoluble proteins, carbohydrates, lipids, tanning agents, minerals and hop components.

With the gentle, efficient and aroma-enhancing Omnium brewing process, substantially more of the valuable ingredients from hops and malt are obtained for the beer. The brewmaster has full control of the action and is able to brew beers exactly according to his ideas. With the Omnium brewhouse solution, Ziemann pushes the door to a new world of brewery plants. Beer can be beer again: full-flavored thanks to the high yield of ingredients, fully aromatic thanks to the gentle brewing process and individual thanks to the almost complete freedom of the brewmaster in producing creative beers.

The new brewhouse concept has already been implemented in two breweries that could not be more different – in the traditional brewery Schlossbrauerei Reckendorf and the well-known Ratsherrn Brauerei in Hamburg. Never before have there been so many control variables in a brewing process and thus never before has there been such a great potential for flexibility in the brewing process, which is reflected in the enormous variety of beer types.

Schlossbrauerei Reckendorf

The Schlossbrauerei Reckendorf prides itself in combining modern brewing tech

nology and strong brands. Only in 2016, the brewery won the International Craft Beer Award for its Weizenbock. Therefore, no one was surprised that the Schlossbrauerei Reckendorf took the pioneering role in 2018 and installed the first Omnium brewhouse. The existing mill and the whirlpool were continued to be used, everything else was planned and built by Ziemann Holvrieka GmbH. The first brew in the new brewhouse in Reckendorf was produced early in April 2018. Instead of the original two brews per day, each with 105 hl cast-out wort, the Omnium brewhouse was designed for three brews per day with 70 hl each, filling the 210 hl fermentation tanks. (Figure 6)

Despite the expansion to three brews in Reckendorf, the new overall process is faster than the old brewhouse (only 4.5 hours per brew). However, according to graduate process engineer and brewmaster Dominik Eichhorn, who is at the helm of the family-owned brewery in the third generation, speed as such has never been the primary objective of the Schlossbrauerei Reckendorf.

“The decision in favour of the Omnium brewhouse is essentially based on the greater flexibility. Brewhouse processes are subdivided into part processes and thus optimized. We are thus in a position to process a greater variety of raw materials such as old cereal varieties that are nowadays considered as rather unsuitable for industrial production processes”, explains Eichhorn.

Dominik Eichhorn confirms that the previous results and practical experience are very good. “This applies both to the commissioning and to worts and beers”. In the first step of the “flavour matching”, the new brews were blended in the fermentation cellar with conventional worts. The wort aeration could be significantly lowered in order to keep the yeast propagation within the required limits. Currently, only one of the three brews is aerated for ten minutes in order to achieve an oxygen concentration of 1 ppm. This results from the yeast vital substances such as zinc or fatty acids, which have a positive influence on the fermentation process.

In Reckendorf, both the worts and the beers were analysed chemically and analytically down to the last detail. The fact that the analyses of the Omnium beers are flawless is shown in Table 2 and Table 3 as a comparison with the old brewhouse (ASH). The nitrogen contents, the viscosity, higher alcohols and DMS/DMS-P are within the usual ranges. The parameters colour and TBZ are only conditionally meaningful, since the brewery has made a colour correction by adding caramel malt. The Omnium worts and beers contain reduced tanning components. The beer remains stable, since the polyphenols are missing as reactants for the turbidity formation. In general, Omnium beers do not necessarily have to be additionally stabilized. The predominance of the protein fraction promotes the good foam stability with 127 SKZ. The increase in the yield of bitter substances by approximately 10 percent up to the finished beer is also remarkable.

The fatty acid content C6-C18:1,2,3 of Omnium beers is low, which can be attributed to the nutrient supply of the Omnium worts, because only a low level of fatty acid synthesis is required at the beginning of the fermentation process, fewer medium-chain fatty acids (C6-C12) are released into the beer as by-products and the long-chain, saturated and unsaturated fatty acids are completely metabolized. These conditions also lead to a good foam stability. The good zinc and fatty acid supply leads to a vital yeast and thus to a very good fermentation activity. Other small, measured differences are irrelevant for the quality of the beer. Here, it becomes clear that in a lauter tun process, nutrients are strongly absorbed by the trub and are no longer available in the subsequent fermentation process. Brewing technologists and beer lovers can therefore look forward to Reckendorf with great anticipation. The graduate process engineer summarizes his new brewhouse as follows: “Fewer malt polyphenols, gentle hop isomerization and vital fermentation will certainly produce an ideal Pilsner beer.” It is therefore no wonder that the acceptance test of the brewhouse was successful.

Ratsherrn Brauerei in Hamburg

Ratsherrn Brauerei, a trendy urban brewery in Hamburg’s district Sternschanze, opened its plan to implement Omnium by Ziemann in the Hamburg brewery already at the trade fair BrauBeviale 2018 in Nuremberg. In February 2019, the Hamburg team came to Ludwigsburg in order to carry out trials with Nessie in Ziemann’s pilot brewery. The Hamburg-based medium-sized brewery, founded in 2012, implemented the new brewhouse solution (50-hl brewhouse) as a so-called brownfield project: Omnium is running in parallel to another lauter tun brewhouse. The decision in favour of Omnium was simple and was based on the fact that Nessie can be used to produce also very small batches.

In this way, the impressive variety of the scene brewery – about 30 different, partly seasonal or even limited beer types – can be covered. In addition, the newly gained independence of the lautering process results in product development advan- tages when upscaling new beer types. With regard to the viscosity parameter, barley varieties such as oats and rye can now be processed efficiently.

The wort kettle with shell and bottom heating zones has been equipped with the external boiler Dolphin by Ziemann in order to be able to reproduce the differ- ent batch sizes. Ziemann’s hop isomeri- zation vessel Janus by Ziemann is used for dosing very different high amounts of hops, which can also be dosed in the cellar.

On July 3, 2019 the first brew of the beer type Ratsherrn Pilsner was produced successfully and with great enthusiasm of all participants. The following excerpt includes the description of the beer som- melier Birgit Rieber, which she wrote after tasting the first “Nessie” Pilsner. Up to now, five beer types have already been successfully brewed in the Omni- um brewhouse. From Matrosenschluck, an oat white IPA, via the classic IPA up to the Noctopus Imperial Stout with 9.7 vol. %. This year’s Hamburger Senatsbock of the Ratsherrn Brauerei was also brewed in the Omnium brewhouse. This has been ceremonially tapped on January 24, 2020 in the Grundsteinkeller of the Hamburg City Hall in the course of the Senatsbock event.

Technological advantages result in princi- ple from a shortening of the fermentation time, the reduction of yeast addition as well as the extensive omission of wort aeration. However, the fermentation can be controlled individually and flexibly and, due to the optimized pitching condi- tions, can be selected as desired by the brewery. The constant lautering time of about 40 minutes is remarkable and is completely independent of the beer type. This time saving is particularly noticeable when brewing special beers, as lautering times using a lauter tun of more than four hours were previously necessary.