By Stephen Beech via SWNS
New flavors of lager could be brewed using wild yeast from one of the world’s most remote regions, according to a study.
New strains of yeast for brewing – created by hybridizing wild strains of yeast from Patagonia at the southern tip of South America with brewer’s yeast – can yield novel flavors and aromas, say scientists.
Lager beers, which are brewed at low temperatures, dominate the global market, accounting for more than 90% of commercial beer varieties.
However, the flavors and aromas found in lagers are limited by a lack of genetic diversity in the yeast used to brew them.
There are only two types of yeast used worldwide. Both resulted from the hybridization of common brewer’s yeast (Saccharomyces cerevisiae) and a wild, cold-tolerant strain (Saccharomyces eubayanus), say scientists.
For the study, published in the journal PLOS Genetics, researchers created new types of lager yeasts in the lab by hybridizing brewer’s yeast with natural isolates of wild S. eubayanus from Patagonia at low temperatures.
The team grew the resulting hybrids in ways to encourage their fermentation qualities.
Further analysis showed that the strains had mutations in genes that enhanced their ability to metabolize certain types of sugars, which resulted in “unique” aroma profiles and high alcohol production.
The researchers say the success of the new strains could be traced back, in part, to the fact that they inherited their mitochondria – the organelle that powers the cell – from the cold-tolerant wild strains, not the brewer’s yeast.
Study co-author Dr. Francisco Cubillos said: “Overall, the new findings show that the genetic diversity found in wild yeast strains can be tapped to develop new lager yeasts that are suitable for industrial production.
“Our study takes advantage of the great genetic diversity of wild Patagonian yeast to create novel hybrid strains of lager beer with enhanced fermentation capacity and unique aroma profiles.”
Dr. Cubillos, of the Universidad de Santiago de Chile, added: “We hope that novel lager yeasts will be considered to diversify the current repertoire of beers available worldwide.
“The Patagonian Forest is a reservoir of hidden genetic diversity, and we are committed to uncovering its potential.
“Our next steps include continuing to explore and characterise these yeasts to better understand their properties and applications in brewing.”
