Saccharomyces eubayanus, a type of yeast, is a likely parent of the lager brewing yeast, Saccharomyces pastorianus.Lager is a type of beer created from malted barley and fermented at low temperatures, originally in Bavaria. S. eubayanus was discovered in Patagonia, possibly being an example of Columbian exchange.The South American origins of S. eubayanus have been subsequently challenged by genomic and phylogenetic evidence suggesting a Tibetan origin.