Cork taint is a contaminant found in a percentage of natural cork. It is most commonly caused by trichloroanisole (TCA), pictured at left.
At higher levels, TCA can make a wine smell lightly, or strongly, like a moldy basement, ruining the experience. At lower levels, TCA mutes aromas and flavors, substantially decreasing enjoyment even when one is not necessarily aware of its presence.
In addition to wine, TCA also commonly contaminates fruits and vegetables. Baby carrots, for example, have widespread TCA contamination issues.
When a wine is contaminated by TCA or another moldy contaminant, it is often referred to as ‘corked.’ Note that this term should not be used to describe other wine faults. It specifically refers to the wine being contaminated by TCA or a related compound.
In my experience tasting wines for review from 2015 to 2022, between 3-6% of wines I have tasted that were closed by natural cork showed signs of TCA taint or some other moldy contaminant. These findings are largely consistent with those from the Cork Quality Council, which found an average of 3% of corks contaminated through September 2021 using GCMS testing (numbers were higher in some previous years). As of Q1 2023, the group reports seeing an average of 1%.
Below is a summary of articles I’ve written about cork taint, ordered roughly by overall utility.
Updated September 2023.