We amplified and sequenced internal transcribed spacer regions (ITS) in order to identify fungal species in our beer samples (Figure 1 A). We had an average library size of 600K reads (min 350K, max 2400K) per sample we detected 88 fungal species in total, including 52 unique occurrences (Figure 1 B). We identified a variety of wild yeast species in commercial beers, with some brews containing traces of up to more than 30 different fungal species. Using hierarchical clustering, we built a proximity tree of the different beers (Figure 2).