Volatile acidity (VA) is the measure of volatile acids in wine, primarily acetic acid, along with related compounds such as ethyl acetate. At elevated levels, VA can produce aromas reminiscent of vinegar, nail-polish remover or solvent. Small amounts may occur naturally during fermentation and can contribute lift to some wines, but excessive volatile acidity is generally considered a fault.
Acetic acid bacteria can produce acetic acid when wine is exposed to oxygen, particularly when hygiene, temperature or sulphur dioxide management is inadequate. Yeasts and other microorganisms can also contribute to volatile acidity during fermentation. Ethyl acetate, formed from acetic acid and ethanol, can add a solvent-like or nail-polish aroma.
Low levels may be difficult to identify and can seem like aromatic lift. Higher levels produce clear vinegar, solvent or nail-polish-remover aromas and can dominate the fruit. Perception varies between tasters and wine styles, but pronounced VA is usually a defect rather than a desirable characteristic.
Wineries reduce the risk through sound fruit selection, clean equipment, appropriate fermentation management, limiting unwanted oxygen exposure and monitoring microbial activity. Once volatile acidity is excessive, it is difficult to correct without changing the wine.
Example: a red wine with a sharp vinegar smell and a nail-polish-remover aroma may have excessive volatile acidity.
Chef’s note: a small amount of VA may be tolerated in some styles, but a strong vinegar or solvent character should be treated as a wine fault during restaurant service.
This term is one of hundreds covered in depth across OCS courses, learning paths, and 1-on-1 coaching with Chef Eric.
