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Fermentation/Maturation

Breweries devote continuous attention towards improving and stabilising beer quality. In order to fill the perfect beer, choice of raw materials as well as the brewing process is subject to the most stringent specifications and tests. Unfortunately, thorough quality monitoring often stops at this point.

Barrels have held beer since they were invented in the early Iron Age between 800 and 900 BCE, or perhaps even earlier, by a wood-bending folk with access to vast forests, most likely by the Celts. There has recently been a resurgence in the use of barrels among craft brewers. How these innovative brewers employ barrels to create distinctive beers is in many ways novel and unique and at the same time steeped in centuries of tradition. Beers acquire more character and complexity by spending time in barrels for a variety of reasons. In this second installment in the series, we delve into why brewers have come back to these ancient wooden vessels by looking more closely at how barrels are produced as well as the flavors and aromas the wood contributes to the beverages stored in them.


The relevance of dimethyl sulfoxide (DMSO) as a precursor of dimethyl sulfide (DMS) is discussed in the following contribution. It explains the theoretical background to formation of DMSO as well as its reduction to free DMS during beer fermentation. As a starting point for further scientific brewing investigations, this part also includes an overview of DMSO concentrations in various malt types.


The diacetyl level is regarded as an essential criterion for beer maturation. Its control is crucial for a short and consistent maturation time and thereby a dependable throughput. To prevent too high diacetyl levels generated by brewers’ yeast during fermentation the enzyme alpha-acetolactate decarboxylase (ALDC) can be applied. DuPont Industrial Biosciences, Brabrand, Denmark, developed an enzymatic solution to minimize the formation of diacetyl. Alphalase® Advance 4000 is commercially available since 2015 and especially designed to provide a short consistent maturation period; due to its concentrated form it can be applied at dosage levels as low as 0.5 to 1.0 g/hl into cold wort at the beginning of the main fermentation. The resulting effect is diacetyl levels close to or below flavor threshold at the end of the main fermentation to ensure a consistent throughput, even during peak season.


The trend, as it is known today, of ageing beer in wooden casks is spreading rapidly in artisanal (and other) fermentation cellars. However, there is nothing new about this almost global phenomenon, which dates all the way back to antiquity. This article is the first part in a new mini-series on barrel aging which will be published in the following issues of BRAUWELT International.


Large breweries have been able to access the business benefits of simulation software for decades. The costs of purchase and implementation tends to mean that smaller companies, such as craft brewers, are not able to access these applications, even though they could gain considerable competitive advantage through their use. Generic simulation templates running on the Cloud offer small and medium sized companies the benefits of simulation without the time and cost of traditional bespoke solutions.


Experience over a five-year period of full throughput using anaerobic co-digestion of brewery yeast for biogas production is described in this contribution. The brewery, with a total amount of available yeast (0.7 v/v %), had a 26.2 % increase in COD load and a 38.5 % increase in biogas production resulting in an increase in the biomethane/natural gas substitution ratio in the brewery from 10 % to 16 %.


Containers are becoming lighter, more customized and often more delicate. At the same time, the performance of filling systems is improving, while demands to reduce costs are on the rise. The key questions within this context are as follows: How can one both monitor and optimize pressure on containers in the bottling line in order to reduce scuffing and broken bottles? How can the necessary optimization be carried out using simple and efficient methods and how can their efficacy be evaluated? This article shows to which extent this challenge can be met with the Quantifeel System© developed by Smart Skin Technologies Inc. in Canada.


Through the development of a unique design, Christian Gresser Behälter- und Anlagenbau GmbH of Regensburg was able to fulfill the wish of brewmaster Axel Kiesbye by realizing his idea for an open, cylindroconical fermenter for the transparent fermentation cellar at Trumer Pils in Austria. From this singular notion, a concept that is now in demand in the United States was born. Despite the challenges inherent in the design, a system for automated cleaning and removal of the contents and of the carbon dioxide produced during fermentation was developed – a first for open tanks.


Dosing or pitching the exact amount of live yeast into each fermenter is critical for consistent fermentation performance and beer quality. Automatic dosing systems can provide a solution. However, in a typical expanding craft brewery, there can be a plethora of fermenters and yeast storage vessels located around the site, and the usual dosing equipment is not portable. Therefore Aber Instruments Ltd, Aberystwyth, UK developed a portable yeast pitching skid for use in craft breweries that can be connected to any yeast storage vessel or fermenter. A case study was carried out at the Meantime Brewing Company, London, UK.


Top-quality beer from the Ruhr region for the Ruhr region is what private brewery Moritz Fiege in Bochum, Germany, undertakes to produce. Says Hugo Fiege, who now owns the brewery in its fourth generation together with his brother Jürgen Fiege, “Private brewery Moritz Fiege sees itself as a home-brew company equipped with outstanding plant technology.” This statement is underlined by the brewery’s latest investment in a new KHS filling system for glass bottles.