It Takes Gall to Make a Great Beer
BIOLOGY Lager beer a cold-fermented beer invented in Bavaria in the 1500s is one of the world’s most popular alcoholic drinks. But it was only recently that a team led by scientists from the New University of Lisbon in Portugal discovered the origin of its key ingredient: a New World yeast.
For centuries, Europeans used yeast that requires warm fermentation, yielding a stronger beer. The secret to lager’s success was the arrival of a particular type of yeast that ferments more effectively at lower temperatures. It fused with the yeast then commonly used, creating a hybrid. But where did this new yeast come from?
After scrutinizing European yeast collections and the scientific literature and investigating new European yeasts, the scientists concluded that the lager yeast is not European in origin. But across the Atlantic, in Argentina’s Patagonia region, scientists discovered a wild yeast in a beech forest, Saccharomyces eubayanus, that’s so active that the galls it creates on beech trees will spontaneously begin to ferment.
The Patagonian yeast is clearly different from known wild yeasts, but is an extremely close genetic match to the hybrid’s lager yeast. So the next time you have a cold one, thank the long-ago stowaway that carried the yeast across the ocean and into Bavarian cellars- and beer history.