Piety and warmongering aside, the European monks of the Middle Ages are known for the richness of their artistry, music and food – most notably cheeses, wine, spirits and beer. In their quest for crafting and preserving beer, it would seem that the monks may have been among the first, unwitting, scientists of yeast. At least this is what modern studies that pinpoint the origins of the world’s most popular beer suggest.
Two studies, one in 2011 and the second released this month, trace the development of lager to Bavaria in the 15th century. Up until this time, beer, or more specifically, ale, had always been fermented in warm environments, owing to the properties of Saccharomyces cerevisiae, the yeast found in ale, as well as bread and wine. But, the monks discovered that fermentation was taking place within the casks kept in the cool recesses of the caves in which it was stored. By tinkering with this new yeast, the Bavarian monks were able to develop the signature clean, crisp profile of lager.
But where had this new yeast come from? As adept as the monks were at the early science of brewing, they lacked the technology to understand it. Fortunately, technology has caught up with beer. In 2011, by using genome sequencing, the research team discovered that lager yeast contained the genomes of two different types of yeast – that of S. cerevisiae, our familiar ale yeast, but it also contained the genome of a second yeast for which no known wild source existed in Europe.