Ustersbacher: Brewed in a climate-friendly way

Upcycling brewing residues to CO2 neutrality: with the help of brewing technology specialist Krones / Steinecker, the private brewery in Ustersbach utilises its protein-containing spent grains and yeast as a source of protein and energy.

For most breweries, spent grains are just leftovers from the brewing process, which are often only used as animal feed or sometimes even have to be disposed of for a fee. However, there is actually much more to brewing residues – and they offer opportunities that not only pay off in terms of sustainability, but also represent a lucrative additional business for breweries.

Among other things, brewer’s spent grains can be used to produce protein, which is currently in high demand in the food and beverage industry, as well as among producers of food supplements and cosmetics.

The joint development project between Krones / Steinecker and the Bavarian brewery Ustersbach is now demonstrating for the first time how this upcycling process can be successfully realised:

Firstly, proteins are extracted from the residual materials. This is done by means of dispersion, hydrolysis and subsequent membrane filtration.

In the second step, the remaining biomass is acidified, and a mineral fertiliser is then produced using an ion exchanger (which can also be sold profitably to the agricultural sector).

Energy is then utilised in the form of biogas production, whereby the wastewater from the brewery is also added and purified. By separating the biologically inhibiting protein from the residue, which forms the substrate for biogas production, the biogas plant can be significantly smaller and therefore more cost-effective, while producing the same amount of energy.

Awite supports the control of this complex process with measurement data of the gas composition in the acidification reactor and in two buffer tanks (retentate and permeate), which is continuously determined by the AwiFLEX XL gas analyser.

Three years ago, the Ustersbach brewery received the ‘TOP100’ award as one of the 100 most innovative companies in Germany for its ‘The Green Way’ concept, which was launched in 2004. The goal since the beginning: to produce the best beer in the most climate-friendly way possible with consistent energy management. In plain language, this means making the brewery energy self-sufficient (thermally and electrically) and CO2 neutral.

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