How can you tell if wine has leaked through a plastic cork?
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Dear Dr. Vinny,
I have a question about plastic corks. With a natural cork, when wine leaks or seeps up to the top of the cork, you can see visual evidence of the wine on the cork itself. Is this possible with synthetic corks, or would you have to see the leakage under the foil covering?
—David, Clifton, N.J.
Dear David,
Had you asked me about synthetic corks a few years ago, I might have grumbled a bit about them. Some were so rigid I’ve actually cracked the glass bottle (or my corkscrew) trying to wrestle them out.
But these days, when I come across a synthetic cork, they seem to fit better and are easier to extract. They are still made from thermoplastic elastomers, but they seem to be more flexible. One boon of synthetic corks is that they eliminate worries about the wine being contaminated with TCA from natural cork.
That said, leakage remains a concern with synthetic corks. It’s possible the cork doesn’t fit perfectly or has a crease or imperfection. And if your wine gets too hot, leaks can certainly occur, no matter the closure. Be sure to check out our tips for storing wine to minimize the chances of leakage or other damage.
You’re correct that synthetic corks won’t absorb any wine to give you a signal that your bottle may have leaked. But yes, if there’s a foil over them, you might see signs of leakage, or the top of the bottle might be a bit sticky.
If you suspect a bottle of wine has leaked—no matter the closure—you can’t draw any conclusions about the wine inside. It might be compromised, but it might be perfectly fine. And even if it doesn’t taste good, it’s still safe to drink. They only way to tell for sure is to open up the bottle and take a taste.
—Dr. Vinny
