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 microbes at very low levels before they convert important flavor precursors into undesired products and leave irreversible damage on aging wine.

Curious to learn about the details of PCR? Follow along with our biochemists in the video below as they debut our newest laboratory offering for GWH clients and analyze a sample for microbial spoilage bacteria.

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