More sustainable way to brew beer: Non-stop fermentation saves resources

Is it possible to increase the energy efficiency of brewing? Researchers from the Technische Universität München believe they have found a way to do just that.

They have developed a fermentation process that takes place in stages over a number of interconnected tanks. The tank system can be operated continuously over a period of several months, which leads to an energy reduction. The new method also promises significant resource efficiency gains.

Fermentation and lagering are the most time-consuming stages in the brewing process. In these production steps the beer develops its characteristic flavors and aromas. "The taste and quality of the beer depend to a large extent on the type of yeast used, and the applied fermentation process," explains Konrad Müller-Auffermann of the Research Center Weihenstephan for Brewing and Food Quality.

Breweries normally use large, cylindroconical, stainless steel tanks (CCTs) for fermentation. These tanks have only one inlet and outlet at their base for filling and discharging the beer and yeast. Once fermentation and lagering have been completed, the breweries release the carbon dioxide that has built up in the tanks and clean them thoroughly – a process that usually takes several hours. Subsequently the tanks can be refilled with the next batch.

Therefore the tanks cannot be used for production during filling, emptying and cleaning. In order to eliminate these downtimes, a TUM scientist has developed a new process that allows continuous fermentations in a number of interconnected tanks. "We simply equip the existing tanks with a central pipe, with open bottom," says Müller-Auffermann. "This enables the combination of tanks in order to create a reaction cascade."