Acetification

Acetification meaning in wine

Acetification is a wine fault that occurs when ethanol in wine is oxidized to acetic acid through the action of acetic acid bacteria, primarily Acetobacter and Gluconobacter species. This process transforms wine into vinegar, producing sharp, pungent aromas and flavors reminiscent of nail polish remover or vinegar. The bacteria require oxygen to survive and multiply, making wines stored in partially filled containers or those with compromised closures particularly susceptible. Acetification typically begins when wine is exposed to temperatures above 15°C (59°F) combined with oxygen exposure. The process is irreversible and can be detected at concentrations as low as 0.7-1.1 grams per liter of acetic acid. Prevention involves maintaining proper sulfur dioxide levels (typically 25-50 ppm free SO₂), minimizing oxygen exposure through proper storage and handling, and maintaining cool, stable temperatures. While small amounts of acetic acid naturally occur during fermentation and can contribute complexity in minute quantities, excessive levels render wine undrinkable. Winemakers monitor acetification through regular laboratory analysis and sensory evaluation, as early detection allows for corrective measures such as sterile filtration or blending with unaffected wines.