So, back in 2011 I mentioned the discovery of S. eubayanus in the wild in Patagonia. That’s exciting because S. pastorianus (often called “lager yeast” in English: it’s the yeast used to make a lot what the world recognizes as “beer” today, for better or worse) is actually a hybrid of two other kinds of yeast: that is, it was formed when two different kinds of yeast contributed DNA to a hybrid yeast. Those two yeasts were S. cerevisae (familiar as top-fermenting brewer’s yeast, but in fermenting other alcohols and making bread as well), and an until-recently mysterious, never-before isolated strain that got called S. eubayanus. The latter yeast was …