Orange-colored galls, such as these pictured in 2010, from the beech tree forests of Patagonia have been found to harbor the yeast that makes lager beer possible. Five hundred years ago, in the age of sail and when the trans-Atlantic trade was just beginning, the yeast somehow made its way from Patagonia to the caves and monastery cellars of Bavaria where the first lager beers were fermented. University of Wisconsin-Madison Genetics Professor Chris Todd Hittinger and colleagues from Portugal, Argentina and the University of Colorado describe the lager yeast, whose origin was previously unknown. (Photo by Diego Libkind, Institute for Biodiversity and Environment Research, Bariloche, Argentina)