Scientists discovered an ingredient in hops which they think could slow the progression of degenerative diseases such as Alzheimer’s and Parkinson’s, it was announced in January.

Using next-generation sequencing techniques, scientists have traced the origin of the yeast used in making the most popular lager all the way back to 15th century Bavaria in Germany. A lighter and smoother beer was the result, which grew in its popularity, spreading to the nearby Czech kingdom of Bohemia.

While lagers now represent 94 per cent of the world beer market, the origins of different hybrid lineages has been a bone of contention for lager beer makers.

The accidental hybridization of yeast has parallels in the deliberate breeding used to improve plants and animals in agriculture. Then, in the 21st century, researchers looked at the two main strains of lager yeast and compared their genetic makeup to determine their origin and evolution.

They have also found that genetic signs of domestication are there in the lager beer yeast that is used by breweries at present. Over the years, Saaz has fallen to the side as Frohberg has become the yeast of choice for most lager brewers. “Although these hybrids were different from the start, they also changed in some predictable ways during their domestication”, he continued. Since each lineage had different ratios of S. eubayanus and S. cerevisiae, the scientists determined that the two yeasts mixed, or hybridized, multiple times as they evolved.

Researchers looking for modern examples of the original S. eubayanus have found plenty of it in the Southern Hemisphere but only a few samples in the Northern Hemisphere, including strains in Wisconsin and in China.

Since the discovery, Hittinger has been testing the DNA of the two strains of yeast to get a better idea of the history of lager yeast. The findings, Hittinger said, reveal “how little we still know about natural Saccharomyces diversity”, and since only a subset of the species have been utilized by industry, “there is a lot of potential to create novel, custom brewing or biofuel strains”. The question that is still unanswered is how did the German monks find a sample and use it in their beer.

In 2011, Hittinger’s team figured it out: a species called Saccharomyces eubayanus, discovered, oddly enough, on the sides of beech trees in chilly Patagonia, in South America. From S. eubaynus, they were able to isolate traits found in the domesticated hybrids, that are used in brewing lager.