🍷 2,4,6-Trichloroanisole

Trichloroanisole, or TCA, is the compound that causes cork taint in wine. Even tiny amounts, measured in parts per trillion, give wine an unpleasant smell of a damp cellar, wet cardboard and mould.

Where it comes from. It is formed by moulds when they meet chlorine-containing compounds. This can happen in cork bark, in wooden barrels or in the cellar itself. Most often the compound gets into wine from the cork, which is why people say a wine is "corked". Wine with this fault is not dangerous to health, but it is unpleasant to drink, and the fruit aroma disappears.

That is why alternatives are sought: synthetic cork and the screw cap. Cork makers now test their raw material so that TCA does not get in. The fault can be noticed by smell right after opening. In a restaurant such a bottle is usually replaced. It is an example of how the tiniest chemistry decides the fate of a wine.