I feel like corked wine can be a concept that is hard to understand…until you taste it. And then it becomes abundantly clear. Corked wines are so called because the wine is actually tainted by an organic compound that comes from the cork. That compound is called trichloroanisole. So quickly memorize that and learn how to pronounce it correctly. Or you could just call it TCA as everyone else in the wine industry does.
Basically what happens is that when TCA comes in contact with the wine it causes a musty aroma. In fact TCA can be perceptible in wine even if its concentration is only a few parts per trillion. This musty, moldy, wet cardboard aroma overtakes the wine and strips out all the fruit flavors.
The thing about corked wine is that there is a big range of strength. At the lower end it can be almost imperceptible and will merely dull the flavors of the wine. Which means if you are not familiar with it or not able to pick it out you may just think you are drinking a mediocre wine and not a flawed bottle. That means that when you come across a wine that is strongly and perceptibly corked you should taste it. Not because it tastes good, but because once you get that flavor and that aroma, you will be able to pick out a corked wine, even a very mildly corked wine, from a mile away.
There are a few different theories about why this occurs. Some people think it is something that occurs during the sterilization of the cork, but others think that it is just something that is inherent in the cork itself. Either way no one has really figured out what causes it for sure, or a way to stop it before it taints the wine. Otherwise it wouldn’t still be such a big loss for the wine industry. Different studies have different numbers but the basic consensus is that TCA affects anywhere from 2-7% of bottles. Which might not sound like big numbers but if you’re a small winery producing 1,000 cases a year, TCA could taint at minimum 240 of your bottles or by the highest estimates 840 of your bottles, 70 cases of wine.