It’s All in the Microbes
The devil is in the details, the sages tell us.
So, it seems, is the terroir.
The French word that describes the often-inscrutable blend of soils, climate, geography and more that gives wines their unique character and makes the wines of one region or microclimate different from those of another, is apparently also influenced by the microbes that grow on the skins and stems of wine grapes.
According to a study done by a quartet of researchers at UC Davis, different soils, regions, climate conditions and grapevines themselves also host "whole microbial communities" that are unique to each. These collections of microbes play "critical roles in grape and wine production and quality formation," helping create the distinctive terroir that is "a critical feature of perceived product identity." In other words, microbes contribute to the character that makes Bordeaux Bordeaux, which is why we're willing to shell out the equivalent of a down payment on a new Mercedes for a case of Chateau Margaux.
Analysis of Chardonnay and Cabernet Sauvignon grapes showed "significant regional patterns" of microbial activity across different vintages, the study reports, with Napa Valley Chardonnay hosting certain types of bacteria less prevalent in other Chardonnay grown in other regions. Even regions with similar climates showed different microbial signatures, variations that were also found in different vintages from the same region.
Why do we care about all this?
Because understanding the role these various microbial communities play in wine production may allow growers and winemakers to improve their products at the most elemental level, thereby "improving the supply, consumer acceptance and economic value of important agricultural commodities."