Researchers may be one step closer to uncovering how lagers first came to be. A recent discovery in Ireland points to the early production of lagers in Europe.
An ancient strain of yeast — named an ancestor to lager-producing strains — was identified by undergraduate researchers studying genome sequences on a university campus in Ireland, according to a Dec. 7 journal article published in FEMS Yeast Research. This particular strain, believed to be a parent to varieties used today, could point to how the first lagers were brewed in Europe.
Lager brewing typically utilizes the S. pastorianus strain yeast, according to an article by Irish public service media RTÉ. The genome sequence of the recently-discovered yeast indicates that it’s the cold-resistant and historic S. eubayanus strain, an assumed parent to the S. pastorianus — likely a result of mating with similar strain S. cerevisiae.
Methodology included lab testing of the strains at the University College Dublin. Researchers extracted soil nearby to the campus, then used a chemical process to isolate two potential strains of the yeast. Genome sequencing then compared and matched the yeast to known S. eubayanus strains.
It was previously assumed that this yeast was found only in Patagonia, as strains had been found in South America, North America, China, Tibet, and New Zealand.
“Since the discovery of S. eubayanus isolates in Patagonia in 2011, it has been hypothesized that isolates would be found in Europe, and indeed modeling by Langdon et al. (2020) showed that Europe is a suitable location,” the journal’s conclusion states. “Our discovery of isolates in Ireland is consistent with the ‘Out-of-Patagonia’ hypothesis, that S. eubayanus evolved in Patagonia where it adapted to cold and harsh conditions, and then spread to the rest of the world, probably in the postglacial period.”
The full report, available in the FEMS Yeast Journal, describes the scientific process to identify the strain — it’s just one more puzzle piece to learning how early European lagers developed.