Whenever you order a bottle of wine at a nice restaurant, the waiter typically starts by pouring a small amount into a glass and asking you to taste it. Amongst other reasons, one of the reasons you’re tasting that wine is to see if it’s “corked,” which means it has become contaminated with cork taint, which affects the taste and smell of the wine.
While corking does happen to wine, it doesn’t happen that often. Roughly 5% of wines that use a natural cork wind up corked. That means the chance of you getting a contaminated bottle while you’re out on the town are pretty slim, but if you’re a big wine drinker (and buying bottles night after night), the chances of coming across a corked bottle increase.
So, on to the important question: How do you know if a wine is corked?
The good news is that if you end up with a corked wine then it’s very likely you’re going to be able to tell.
What you’re looking for is something that smells somewhere between a wet dog and a wet newspaper. You probably haven’t experienced a ton of those in your life (or maybe you have), but it’s a pretty distinctive scent that’s off-putting enough you probably won’t want to even take a sip of that wine in front of you. Imagine a cardboard box that’s been sitting on your front porch in a rainstorm and then warmed up by the sun later. That smell.
When you do take a sip, a corked wine will also taste pretty one dimensional, without any of the fruit characteristics that you typically expect from a glass of wine. Sometimes corked wine can also taste astringent.
Sometimes people think that when they see small pieces of cork floating around in the bottle that means that a wine has been corked. While the bottle certainly could be, small cork particles is not an indication of corking.
The kind of corking we’re talking about come from the presence of the chemical compound TCA. It happens when natural fungi in the cork come in contact with things that are found In winery sanitation and sterilization products. The issue comes from the use of specific cleaning products, which most wineries abandoned in the mid ‘90s after discovering they could contaminate their juice (although some wineries still use the products). That means that your chances of finding a “corked” wine are significantly greater in an older bottle than one bottled from the ‘90s onward.
In order to be “corked” a wine also has to use a natural cork. If your wine has a synthetic cork or screw cap, then it’s not corked.