Most wine drinkers are probably familiar with the term ‘corked wine’, but not many wine drinkers really know what a corked wine tastes like, how a wine becomes corked in the first place, or how to detect a corked wine.

If you’ve ever had a wine that just didn’t smell or taste quite the way you expected, or a wine that just didn’t taste right, the problem may not be your palate. The wine could be “corked,” or tainted with a chemical compound that the wine maker never intended to get into the bottle called TCA. The wine is definitely safe to drink, it just may not taste how it’s supposed to. Here’s what to look for—or smell for—to help you determine if a wine is corked when you open it.

TCA, or Trichloroanisole, is a natural byproduct from a common airborne fungus when it comes in contact with some kind of chlorinated chemical or compound. Sometimes that interaction takes place in the cork that goes into wine bottles, and if it does, TCA can—depending on its concentration—dramatically change the taste of a wine or just obscure and overwhelm some of the subtle flavors that the winemaker intended you to enjoy.

While unpleasant to taste, cork taint is not in any way harmful to humans. Corked wines smell and taste of damp, soggy, wet or rotten cardboard. Cork taint dulls the fruit in a wine, renders it lackluster and cuts the finish. The obviousness of the corked smell and taste depends both on the extent of the taint, as well as the wine drinker’s sensitivity to it (aka your cork taste threshold).

Sometimes it is barely noticeable and other times it knock your socks off the moment you open the bottle.

If you’re drinking in a restaurant, you can always let the waiter know and they’ll usually bring you a glass from a fresh bottle. If it’s really bad and you’re drinking at home, it might be a good time to open a different bottle. Just be sure that you’re not claiming a bottle is corked just to get a free glass—or replacement bottle—of wine.

However, Corked or tainted wine is not a very common phenomenon. I open quite a few wine bottles every week, and these days it is often several weeks before I find a tainted wine.I would love to hear from readers on your questions and /or experiences with corked wines.