Beer Yeast Could Be Secret to Better Chocolate

How can chocolate be made better? By using the same yeast used to brew beer, a group of Belgian researchers have found.

Microbial fermentation is an important part of making chocolate, just as it’s an important part of making products such as beer and wine. But in contrast to the controlled, modern processes used to make America’s favorite alcoholic beverages (a 2014 study found that 41% of U.S. drinkers typically drink beer and 31% typically drink wine, as opposed to only 23% who drink liquor), the fermentation process for cocoa is spontaneous.

That means cocoa farmers generally encourage fermentation by exposing the beans to whatever microbial populations happen to exist at their farms. But since the eventual flavor of the chocolate will be highly dependent on which microbes are present, some chocolate ends up with a very undesirable flavor.

“Chemical analyses as well as tasting the chocolate showed that the chocolate produced with our best yeasts is much better and more consistent than the chocolate produced through natural fermentation,” Kevin Verstrepen, a professor of genetics and genomics at the University of Leuven and the Flanders Institute for Biotechnology in Belgium, explained in a July 15 news release. “Moreover, different yeasts yielded different chocolate flavors, indicating that it would be possible to create a whole range of specialty chocolates to match everyone’s favorite flavor.”

To get those “best yeasts,” Verstrepen and the other researchers looked at more than 1,000 strains used in the alcoholic beverage industry and cross-bred high performers. Those hybrids were then passed to an industrial partner, Barry-Callebaut, which made chocolates based off each strain.

Unanimously, the (“very eager”) taste-testers voted that the chocolates made with hybrid yeasts from the alcohol industry tasted better than naturally fermented chocolates.

The full study, published in the journal Applied and Environmental Microbiology, is available online under the title “Application of a Breeding Strategy to Generate Robust Yeast Starter Cultures for Cocoa Pulp Fermentations.”