The term ‘corked wine’ is often misunderstood – there is actually no visible defect in the cork. Rather a corked wine is the result of a tainted cork due to the presence of a chemical called TCA (for you chemists out there - 2, 4, 6-trichloroanisole). The most likely reason for its presence is as a result the use of chlorine to sterilize the corks.
Whilst the TCA chemical itself is harmless, its presence produces very unpleasant odours and makes wine taste ‘flat’ and uninteresting. Unfortunately TCA is detectable in concentrations as little as one part per million! When TCA is present in high concentrations it is immediately very obvious with a characteristic musty or ‘wet dog’ smell. Further bad news is that there are degrees of cork taint. When TCA is at very low levels it is hard to discern and leads to the conclusion that “this bottle just does not seem like the last one we drank”.
Regrettably, the presence of cork taint is higher than what the wine industry would like to admit – up to 7% of wines using cork could be TCA affected according to some estimates. This lead to a revolution with the adoption of alternate closures, the most common being the screw cap. The screw cap has its advantages – no cork taint; very easy to open; and the wines can be stored upright.
The screw cap is now almost universally used in wines from Australia and New Zealand. There has been much slower up take in the USA and Europe with the latter wines being hampered by regulations that dictate the use of “natural cork” (even though the screw cap is a European invention).
As one prominent Australia wine producer commented “It is hard to understand why we still cling to stuffing tree bark into the bottle just as like the ancient Greeks”.
Its hard to disagree when there are alternatives– if only for the simple reason that using modern closures means - NO CORK TAINT!