Scientists traced the origins of the yeast used to make lager beer back to 15th century Bavaria, Germany, using specific sequencing techniques. The study was published in the journal Molecular Biology and Evolution.
Yeast is the agent of ferment in alcoholic beverages.. More precisely, yeast cells join with carbon dioxide in the process of producing beer.
The beer’s variants are ales and lagers. Ale is a beer fermented in an open vessel using yeasts rising to the top of the brew, whereas lager originates in Germany, and is fermented for quite a long time at a low temperature.
Lager may be golden, pale, amber or dark. Pale lager is widely consumed worldwide and variants of lager beer include Pilsner and Bock, while dark lagers are Schwarzbier and Dunkel, for example. Lagers nowadays represent 94 percent of the beer market.
Ale, on the other hand, is brewed from malted barney through a warm fermentation process. In comparison to lager yeasts, ale yeasts ferment more quickly and often produce a sweeter taste.
Moreover, the original yeast, scientifically known as Saccharromyces cerevisiae, has been used for centuries to make ale beer, bread and wine. But an innovative aspect, according to researchers, was that the origins of lager beer were traced to 15th century Bavaria, when German folk observed the fact that beer stored in caves during winter time continued to ferment.
Thus, a smoother and lighter beer began dominating 19th and 20th century among beer enthusiasts, especially in America. Lager yeasts are hybrid fungi made of two different variants, S. cervisiae and S. eubayanus. The latter species was discovered in 2011.
The S. eubayanus wild yeast species helped scientists from the University of Wisconsin-Madison develop a high-quality genome via next generation sequencing. This wild yeast variant draws its origins from Patagonia.
Corresponding study author of the University of Wisconsin-Madison, Chris Todd Hittinger, said lager yeasts did not originate once, exclusively. The correlation between the two species of yeast – S. cervisiae and S. eubayanus – as different as humans and birds, happened twice, at the least.
He finally pointed out that despite the fact these hybrids had been different from the start, they did change in a predictable manner during their domestication.
Hittinger and his team said that they would continue studying beer yeast DNA, in order to better comprehend “biogeographic diversity that somehow gave rise to lager.”
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