Yeast and Winemaking
Spontaneous Wine Fermentation
The notion that wine should be terroir-driven, and that commercial yeast somehow obscures terroir effects, has prompted a resurgence of spontaneous (or native) fermentations in wine regions. This trend seems to be driven by the perception that uninoculated fermentations produce wines of higher quality, or at least more sensory complexity. Stylistic distinction is the driving force is behind natural fermentations as well as consumer preference for a perceived natural product. Recent studies have shown that all vineyards (and even individual vines) have a unique microflora fingerprint. In fact, each grape variety and each vintage has a different microbial makeup. So, for winemakers looking to showcase an individual vineyard and vintage, allows wild yeasts to factor into the fermentation is the most honest reflection of what's going on at that site.
Benefits and Risks of Native Yeasts
Some winemakers believe that the use of native yeast helps contribute to the unique expression of terroir in the wine. It is believed that by fermenting the wine with the various native yeast strains, the wine will be more complex with more positive descriptors such as increased mouthfeel and aromatics. The range of flavor compounds produced by different non-Saccharomyces yeasts includes terpenoids, esters, higher alcohols, glycerol, acetaldehyde, acetic acid, and succinic acid. Although far less studied, wine color can also be affected by non-Saccharomyces yeast.
Click on the following topics for more information on yeast and wine production.
