Acescence

Acescence meaning in wine

Acescence refers to a wine fault characterized by a sharp, sweet-sour, and vinegar-like tang that develops when wines contain elevated levels of volatile acidity, primarily acetic acid. This condition occurs when acetic acid bacteria (Acetobacter) convert ethanol into acetic acid in the presence of oxygen, typically during fermentation or aging processes with inadequate sulfur dioxide protection. While small amounts of volatile acidity can add complexity to wine (generally acceptable up to 0.6-0.7 g/L in red wines and 0.5-0.6 g/L in white wines), acescence becomes a noticeable defect when levels exceed 1.2 g/L. The characteristic aroma resembles nail polish remover or vinegar, often accompanied by a burning sensation in the nostrils. Acescence can develop from poor sanitation, excessive oxygen exposure during winemaking, or contaminated equipment. Once established, this fault is irreversible and significantly diminishes wine quality. Prevention involves maintaining proper sulfur dioxide levels, minimizing oxygen contact, and ensuring sterile winemaking conditions. In severe cases, acescent wines become undrinkable, though mildly affected wines might be salvageable through blending with sound wine to dilute the volatile acidity to acceptable levels.