Q: The other night, I had some wine that tasted "off"; it just didn't taste right. Someone mentioned that it was "corked" but how can I tell? What exactly is corked wine? Could something else cause the wine to be spoiled?

A: Corked or cork taint is generally used to describe a wine that has been spoiled due to a tainted cork. Cork taint is probably the most common cause of spoiled wine. Other common causes of spoiled wine include presence of a yeast and volatile acidity. These three common causes of wine spoilage are described below.

Cork Taint

A truly "corked" wine is one that has been affected by the presence of the chemical compound trichloroanisole (TCA) in the cork. This causes the wine to smell and taste very musty — like wet cardboard, wet cement, mould, or mouldy orange rind. The wine will often taste completely 'flat' and void of any real taste.

Fortunately, wines with TCA are generally not harmful to drink. Industry estimates that 2-5 per cent of wines bottled with cork may end up spoiled because of TCA. Hence, industry has attempted to solve the problem of corked wine by using closures other than cork. Nowadays, you will find wine bottled with synthetic corks or aluminum screwcaps, which cleanly cap the wine without contaminating the contents.

Yeast (Brettanomyces)

Sometimes a wine is spoiled because of the presence of a spoilage yeast called Brettanomyces. At high levels, it causes wine to smell and taste like a smelly barnyard or wet dog. At low levels, it can actually add character to the wine.

Volatile Acidity

Wine can be spoiled when the acid balance in it is too high and affects the flavour. Wines that are spoiled due to volatile acidity fault will often be described as having a smell and taste that ranges from nail polish remover, vinegar to boiled eggs or burnt rubber.