Around 3% of the world's wine is what people call 'corked'. That has nothing to do with the piece of cork in the neck of the bottle. It means something else entirely.
Picture it. You sit down after a long day, open a bottle you know well, and instead of the flavours you were expecting you get something like wet cardboard. That is a corked wine.
What corked wine actually is
Corked wine is not what happens when you fail to get the cork out cleanly. It is not a dry cork crumbling into the bottle either.
It is a chemical fault. The compound responsible is TCA, and it gets into the wine through the cork. Corks are a natural material, so they can pick up airborne fungi, and the result strips the fruit out of the wine and replaces it with a damp, musty note. Some bottles are barely touched by it. Others announce themselves the moment you pull the cork. However much winemaking has improved, this still happens, and it can happen to any bottle.
How to recognise it
You cannot see it. Even experienced tasters cannot tell by looking at the wine or inspecting the cork. You have to smell and taste it.
If you get a dank, musty, cardboard-like note where the fruit should be, the wine is very likely corked. It will not harm you. It will just taste like a shadow of what it should.
What to do about it
If a bottle you ordered from us arrives corked, get in touch and we'll sort it out. What we can do and how long you have are set out in our refund and returns policy, which is the version that applies.
If it happens when you're eating out, say so and ask for the bottle to be replaced. That is normal and any decent restaurant will do it without fuss.
Cork taint is one of the few genuine faults in wine, and it is worth being able to name it. Now you can. Have a look at what's on the shelf when you're ready for the next bottle.