Sour beers are likely the original beer style and have made a recent comeback in terms of popularity among craft beer enthusiasts. They are made with a bacterial and fungal mix rather than pure cultures of Saccharomyces. yeast as in typical ales and lagers. However, the suite of different microbes and their relative abundances during the course of souring and fermentation remain a mystery. We aim to map part of the sour beer microbiome and identify the organic acids these microbes produce.