Have you ever had a glass of wine that just didn’t taste quite right? While there are a few faults that can taint a good wine, a bad cork is one of the most common. So what is it exactly and how can you identify it?

Let’s start from the beginning.

Where do corks come from?

Cork is made from the bark of Cork Oak trees, which are planted through southwestern Europe, notably in Portugal and Spain, and also into Northwestern Africa. Once the tree has reached around 25 years of age, the bark can start to be stripped for cork by specially trained ‘extractors’. They are harvested once every 9 to 12 years with some trees living to an amazing 300 years old!

What causes a wine to be corked?

Here comes the science. A corked wine, or cork taint, is caused by the presence of a chemical called 2,4,6-Trichloroanisole (or TCA to you and me). TCA can sometimes be created in corks by naturally occurring fungi reacting to the sterilisation process when making the cork. Unfortunately, it takes just a tiny quantity of this TCA to completely spoil a wine. 

How can you identify a corked wine?

Although TCA is harmless, it can render a wine undrinkable. Typically a corked wine will have a musty aroma, which is often likened to wet cardboard, a damp cellar or even wet dog. In some cases this mustiness can be completely overpowering, while in others it can just strip a wine of any fresh aromas.

Can you avoid corked wine?

There is no way to tell if a wine has been corked without smelling it. So you’re going to have to open it up to find out. If you do find a corked bottle (which is bound to happen occasionally given that estimates suggest that up to 2% of all bottles are affected) the best thing to do is to return it for a refund. 

Luckily, in a restaurant you get the opportunity to try before you buy. Next time your server asks if you’d like to try the wine, you now know what you’re looking for!  

Of course, you can cut the chances of finding a corked wine by only purchasing wines with a screw cap. But with so much amazing wine sealed behind a rustic cork, solely sticking to screw caps is not for everyone.

Whether you like to pop, twist or concentrate on what’s in the bottle, there’s a whole world of wine out there ready to be enjoyed. Start exploring.