Cork is the traditional closure for a wine bottle. Yet one of its drawbacks is that it can actually cause a wine fault.  And, have you ever had a bottle of wine that "had turned to vinegar?"  Well both of these wine faults can ruin a bottle of wine. So let's explore the causes.

Cork taint is due to some degree by natural chemical compounds found in cork.  Known formally as 2,4,6-Trichloroanisole (or TCA for short), this compound, when combined with chlorine and mold can result in a wine that smells like wet cardboard, wet cement or a wet dog. And you don't want to smell these scents when drinking a wine.  It only takes a few parts per trillion to taint a bottle of wine. The results can also be very subtle. With faint levels of TCA, a wine will be striped of flavor leaving a normally rich, fruity wine tasting quite dull or muted.  Often it is so subtle that after drinking the wine you are simply left disappointed without being able to determine why.  Although the cork industry states that only 1% - 2% of corks may be tainted with TCA, Wine Spectator found in 2012 that 3.7% of the bottle they sampled were tainted, down from 9.5% in 2007.  So maybe this is the reason for so many disappointing bottles of wine.

In addition to cork taint, another wine flaw is finding a bottle of wine that has "turned to vinegar."  But can wine really turn to vinegar? The answer is technically yes. But not really.  Without getting into too many technical details, the reason that vinegar tastes like vinegar is acetic acid.  And acetic acid can form in wine when it gets 'infected' with Acetibacter bacteria. This bacteria occurs naturally in the air and on fruit. But it isn't really fair to call tainted wine 'vinegar' since it tastes really bad. It's not something you'd want to mix with olive oil and pour over your salad.

If you ever encounter a bad bottle of wine, as odd as it sounds, do smell it and learn from it. And especially if a wine server takes back a bottle after opening it without even pouring it, ask to have them explain how and why the wine is bad.  Use it as a learning moment.

A couple final thoughts. First, there are no negative health affects of drinking tainted wine.  But who'd want to? And, second, if you do come across a bottle of wine that has gone bad, know that you can return it to the store where you purchased it or, at a restaurant, send it back for another one. 

May all your wines be fresh and wonderful! Cheers!