Wine · Terminology

Volatile acidity

Acetic acid and ethyl acetate in wine — vinegar and nail polish at high levels, lift and complexity at low ones.

Volatile acidity — VA — is the fraction of a wine's acidity that can evaporate, and therefore be smelled. It is overwhelmingly acetic acid (the acid of vinegar), usually accompanied by ethyl acetate, which smells of nail polish remover or pear drops. Unlike tartaric and malic acid, VA is a winemaking product, not a grape component.

At low levels VA gives lift and aromatic complexity — some celebrated wines carry noticeable VA as part of their character. Above a threshold it dominates the nose, and the wine is faulty. The line between the two is one of the more contested judgements in tasting.

In practice

  • Produced by acetic acid bacteria and by some yeasts, especially where oxygen reaches the wine — a slack bung, a leaking barrel, high ullage.
  • Aggravated by heat, by botrytised fruit, and by long, warm maceration.
  • The EU caps VA at roughly 1.2 g/L for reds and 1.08 g/L for whites (as acetic acid), with higher allowances for certain sweet and traditional styles.
  • Prevented by clean fruit, topped-up vessels, sound sulfur management and temperature control.

Where you'll meet it

  • As a classic fault in the tasting-fault list, alongside cork taint and Brettanomyces.
  • As a stylistic signature in some traditional Amarone, Rioja Gran Reserva and a good deal of natural wine.
  • In oxidative styles that spend long periods in wood.

Fault or feature?

Ask three questions in order:

  1. Is it the only thing you smell? VA that buries the fruit is a fault, full stop.
  2. Does the wine still taste balanced? A whiff of acetic lift over intact fruit is a stylistic choice.
  3. Is it stable? Rising VA means live bacteria — the bottle will get worse.

Note that ethyl acetate (solvent, nail polish) is much less forgiving than acetic acid (vinegar, sharp lift). Most tasters tolerate the second and reject the first.

The exam angle

  • VA is assessed on the nose, not the palate, and reported as a fault with a named cause: "volatile acidity — acetic/ethyl acetate character."
  • Do not confuse it with oxidation. Oxidation smells of bruised apple, sherry and nuts; VA smells sharp and solvent-like. The two frequently arrive together, because both follow oxygen ingress.
  • Acidity — the fixed acids, by contrast
  • Oxidation — the fault VA often travels with
  • Ullage — the headspace that lets it start
  • Brettanomyces — the other microbial fault

Browse the full wine terminology A–Z →