Meet the Czech Scientists Upcycling Hardened Bread into Beer

In the hopes to reduce food waste, scientists from the Faculty of Agriculture (FA) of Mendel University in Brno brew classic Czech lager from unsold hardened bread.

Since starting this project, they have prepared more than 30 lager recipes, as well as several other recipes for top-fermented beers. 

“Even uneaten bread is a waste in a way. By no means does this mean any soiled or moldy bread, but hardened bread that has not been sold, ” Milan Geršl of the Institute of Agricultural, Food and Environmental Engineering AF, said.

Procedures adapted from the American and British methods of beer brewing inspired the researchers for this project.

However, in these other methods, different types of pastry are used, resulting in a beer that is very different from the classic Czech brew. The researchers, therefore, aimed to prepare a recipe for classic Czech lager, which could be cooked from various types of bread. 

In the project, beer is created in two ways. One group brews beer purely from uneaten pastries, while the other uses bread baked by hand. Thanks to the content of cereals, it is possible to replace part of the malt with bread.

“When we prepare new recipes and use some anonymous pastries from the market network, we have to do an analysis of them. We find out how much fat or salt it contains. Therefore, we decided to go the way of preparing the pastry ourselves and then investigating the effect of different breads on the final beer,” Tomáš Gregor from the Institute of Food Technology AF said. 

Researchers are changing the fat content of pastries, baking sourdough bread or using yeast. In the last two years, scientists have prepared 30 recipes for Czech lager, two of which they plan to apply as a utility model by the end of the year.

It could then be used by large and small breweries or people who brew their own beer for their own consumption. 

Researchers are now planning to try other types of beer, with the hopes of brewing a strong porter or ALE, top-fermented beer.

“I drank about all the batches we’ve made so far, and all the beers were good. Of course, when drinking those alternative drinks here, people have to be open to new things, otherwise, there is no point in doing them at all. When I put half the bread in the beer, it will always taste different. But it is not so far from classic beers,” Gregor added.

The scientists are approaching the utility models in a more conservative manner. The submitted recipes will be similar to classic Czech lagers or top-fermented beers with a very substantial malty taste; they will be more hop-like and bitter.