The lager vanguard evolved into a staple trend, commanding the 19th and 20th-century beer palates, most notably in America.

Moreover, the original yeast, scientifically known as Saccharromyces cerevisiae, has been used for centuries to make ale beer, bread and wine.

The fundamental difference between lagers and ales is in the yeast. Ale, which was a popular drink before beer was discovered, is usually made from a common type of yeast, Saccharomyces cerevisiae. [Raise Your Glass: 10 Intoxicating Beer Facts].

Now a team led by biologists at the University of Wisconsin-Madison are putting genetic analysis to work to get to the bottom of a different sort of compelling question: the evolution of lager beer. Breweries welcomed the finished product and continued replicating the results using the same equipment and barrels over and over inadvertently contributed to spreading of the yeast from one batch to the other.

Corresponding study author of the University of Wisconsin-Madison, Chris Todd Hittinger, said lager yeasts did not originate once, exclusively.

The findings, published in the journal Molecular Biology and Evolution, could provide a road map for future research in the domestication of lager yeasts.

They show two independent origin events for S cerevisiae and S eubanyus hybrids that brew lager beers.

Each hybridization formed one of the major lager strains. The correlation between the two species of yeast – S. cervisiae and S. eubayanus – as different as humans and birds, happened twice, at the least. Both Saaz and Frohberg yeasts contained S. cerevisiae and S. eubayanus genomes.

The outcomes recommend that the Saaz and Frohberg lineages (named for his or her space of origin) have been created by no less than two distinct hybridisation occasions between nearly similar strains of R eubayanus with comparatively extra numerous ale strains of R cerevisiae. But, the yeast can asexually reproduce as long as people passage them. “There were all kind of rituals to ensure inoculation of the wort (the mix of malt, hops and water), prior to understanding that there actually was an organism causing fermentation”, Hittinger says. For instance, yeast cells can sexually reproduce when they are starved of nitrogen and carbon. Refrigeration made it possible to brew lager year-round, and to brew lager in more places and keep it cold until serving.

“Like most evolutionary processes, there’s some serendipity”, he said. The Bavarian monks discovered a new yeast type, which could be used to make beer at low temperatures.

Around 500 years ago, monks in Bavaria changed the history of beer forever when they began brewing in a cave during winter.