Consistent with its widespread use for fermentation, Saccharomyces cerevisiae, or “brewer's yeast” was detected in all beer samples at very high levels compared to other species, accounting for between 11% for the Orval, an ale beer by Belgian Brasserie d'Orval, and 99% of all sequencing reads for the Tempete, an ale from the Swiss brewery Docteur Gab's (90-97% in most samples, Figure 3). More surprisingly, Saccharomyces mikatae, a species used in winemaking \cite{Bellon_2013} was also detected at high level in all samples (0.5% - 5%). Most brews were found to contain low to medium presence of various other yeast species, including Saccharomyces bayanus (used in winemaking and cider fermentation), Saccharomyces kudriavzevii and Saccharomyces pastorianus (used in Lager), Saccharomyces eubayanus (a probable parent of Saccharomyces pastorianus) and Brettanomyces bruxellensis (typically used for the production of the Belgian beer styles). The latter even represented 86% and 15% of the reads in the Orval beer and in the Chicha Beer Experimental respectively.