The unique mutation of two extremely different strains of yeast at two separate times in history made lager beer possible. About 94 percent of the beer made and consumed in the world is lager. The unique evolutionary events that made beer better were discovered by Emily Clare Baker and a host of beer drinkers at Oxford University in Britain. The discovery was reported in the August 11, 2015 edition of the journal Molecular Biology and Evolution.
Saccharromyces cerevisiae and Saccharromyces eubayanus are the two yeast species that make lager beer possible. Storage is the key to the taste and was discovered by Bavarians around 1400. Yeast species were in essence domesticated to make beer. The researchers used a newly discovered wild strain of Saccharromyces eubayanus from Patagonia to decode the genetic history of the yeast that made beer potable and possible.
The Saaz and Frohberg lineages of yeast that were the first used to make lager were found to be nearly identical strains of Saccharromyces eubayanus and ales came from the yeast species Saccharromyces cerevisiae. The two species used to make the majority of beer have evolved to become the same species at least twice since lager has been made. The two species of yeast that are used to make lager and ale are 99.5 percent the same yeast based on mitochondrial DNA tests.
The beer making yeast has undergone further changes as a result of being used to make beer. The metabolism of both strains of yeast has become more attuned to producing fermentation and the metabolism of sugar. The geographical separation of the locations of the original yeasts that made lager and the care that brewers guarded their yeast with also argues for a unique evolutionary event that made beer making better at least twice.
This article is reposted with the author’s permission from examiner.com.
