Wine Analysis Home
- Acetic acid is an organic and carboxylic acid (see diagram).
- Acetic acid is the sharp tasting and main constituent of vinegar.
- Acetic acid is also the predominant acid of what is referred to as volatile acidity.
- Acetic acid is produced by acetic acid bacteria (acetobacter), which are introduced to grape juice and wine by vinegar flies or pre-contaminated equipment or cooperage.
- The loss of grape berry skin integrity, through disease or physical damage, exposes grape juice to bacterial attack with the production of acetic acid.
- Acetic acid bacteria can persist through to the wine, and in the presence of oxygen and low sulphur dioxide (SO2) concentrations can degrade alcohol to acetic acid in wine.
- Acetic acid, at low levels can lift wine flavours.
- At high levels, Acetic acid can affect the taste of wine detrimentally leaving the wine tasting sour and thin.
- High levels may exceed maximum legal limits (1.5 g/L - Aust.).
- Acetic acid is often, but not necessarily, accompanied by the negative aromas and taste of ethyll acetate (nail polish remover odour).
- Expected levels of Acetic acid found in wine are 0.1-0.8 g/L.