What should I do if I think a wine is corked at a tasting?

Dear Dr. Vinny,

I recently attended a tasting hosted by a prominent Bordeaux producer. They were pouring several older vintages, and I thought one of them was badly corked. No one said anything, including the producer. Should I have spoken up, or would it have been rude to do so?

—Kim, Redding, Calif.

Dear Kim,

Thanks for asking a great question about a tough situation. I’ve absolutely been there, and I feel for you.

Let me back up and give some background on the wine flaw you’re referring to. A wine is said to be ‘corked’ or ‘corky’ when it’s contaminated with TCA (2,4,6-trichloroanisole), a compound that makes wines smell musty or moldy. TCA is the most notorious culprit behind corkiness, but other related compounds, including TBA (2,4,6-tribromoanisole), can also cause the flaw.

While some people are more sensitive to the molecule than others, very small amounts—we’re talking about parts per trillion—can be enough to ruin an otherwise beautiful wine. Corked wine is still drinkable, and it won’t harm you, but it will be unpleasant.

Corked wines don’t always smell bad. Their aromas may simply be so muted that they smell like nothing at all. And it can be hard to detect TCA right when the bottle is opened—sometimes the flaw only becomes evident a little later. 

TCA can originate in corks themselves (which is where the term ‘corked’ comes from), but it can also come from wooden barrels, pallets or other items commonly found in a winery. A lab test is the only way to be certain a wine has TCA, but if you’ve ever smelled or tasted a wine with the affliction, it’s a smell that gets stuck in your head.

Back to your question. I’m pretty good at picking the compound out, and I’ve been in every imaginable scenario where I’ve smelled it before someone else does. Romantic dates. Business dinners. Large sit-down tastings. Private tastings with winemakers.

My advice is to first give your wineglass another swirl or two. Sometimes unpleasant aromas ‘blow off’ with additional air. If I still smell something musty, I might just discreetly ask someone near me if the wine seems off to them as well. If they say yes, you can have confidence in your assessment, and you’ve got a pal to back you up if your comment is met with pushback. If not, I would still feel a responsibility to speak up.

Depending on the situation, you might consider going up to the producer privately. You could frame your statement as something like, “I’m curious if the wine is tasting the way you expect it to, because I’m getting some off aromas.”

Or you can just raise your hand and say you suspect it might be a bad bottle. There’s a chance that other people are going to agree with you. Maybe they weren’t confident enough to speak out first, or they’re not as sensitive to TCA as you are.

Hopefully, another bottle will be opened. Typically, winemakers and other people who organize tastings bring extra wine to prepare for the possibility that a bottle could be flawed. And in my experience, most of them are grateful when a flawed bottle is pointed out. They want the wine to show its best, and it’s in their interest to make sure everything being tasted is in good shape. That goes for other wine flaws, not just corkiness. If you’re not sure a bottle tastes the way the winemaker intended, it never hurts to speak up.

But you should still be prepared for the other scenario. Others (including the winemaker) may not agree with you. And you might have to smile and nod and say, “OK, thank you. It’s good to know this is the character of the wine.” And you may have to sit there with a glass of wine you suspect is off and listen to everyone else enjoy it. It’s no fun, but it does happen.

—Dr. Vinny