Microbial biogeography of grapes predicts regional metabolite patterns in wine

Microbial activity is an inherent feature of wine production. The microbial communities of grapes present regionally defined patterns, influenced by vineyard and climatic conditions. However, the degree to which these microbial patterns associate with the chemico-sensory qualities of wine is unclear. We demonstrate that both grape microbiota and wine metabolite profiles distinguish growing sub-regions and individual vineyards within Napa and Sonoma County, California. The bacterial and fungal consortia of wine fermentations, composed from vineyard and winery sources, correlate closely with the chemical composition of the finished wines. Grape must microbiota serve as highly accurate biomarkers for predicting metabolite abundance in finished wines using machine-learning models. The use of pre-harvest microbiota as an early predictor of wine qualities is unprecedented and poses a new paradigm for quality control of agricultural products. These findings add further evidence that microbial activity is a definable feature that quantitatively contributes to wine terroir.