Winemaking is driven by a rich microbial ecosystem. Saccharomyces cerevisiae is responsible for converting the sugars in grape juice into alcohol during primary fermentation. Oenococcus oeni carries out the malolactic fermentation that is responsible for transforming crisp, acidic malic acid into softer lactic acid and improving microbial stability. However, other microbes can produce undesirable, volatile compounds that spoil wine with off-odors and flavors. Luckily, the yeast and bacteria responsible for spoilage can be easily managed if caught early in production. Brettanomyces, Lactobacillus, and Pediococcus are the common culprits of microbial spoilage. Here at Gravity Analytical Laboratories, we use a polymerase chain reaction, or “PCR,” to check for the presence of all three microbes. PCR is a molecular biology tool that allows us to assess the presence of these microbes by screening for their DNA in a juice or wine sample. We can detect these mic