Wine & spirits: Screw the cork

Although wine bottles sealed with natural corks still dominate the shelves of Canadian liquor stores, alternative packaging is making significant inroads. Price and convenience are only secondary benefits; the primary reason for the change is the industry rage against the failure rate of modern corks, which is estimated to be up to 15 per cent. Corks are harvested from the thick, spongy bark of the cork oak tree. As with most living matter, its bark can harbour moulds that contribute to the formation of a chemical that causes wine to develop musty, mouldy and offensive flavours.

Synthetic polymer corks were introduced to the marketplace more than a decade ago to deal with the problem, while preserving the ritual "pop" that happens when a bottle is opened. But plastic corks have proved less than satisfactory on a number of counts: they're more difficult to pull, and with time, they can lead to a reduction of the wine's fruity flavours.

The original screw cap, created in the late '50s, carried with it the stigma of cheapness and low quality because it was often used on cheap wines, but new technology has brought with it a superior airtight seal and medical-grade plastic liners. Today's metal twist-offs have passed the test of time, improving on the ageability of wine and providing more consistency between bottles from the same batch -- something even natural corks have failed to do.

As with most innovations, New World wineries have been quicker to accept the screw cap as the seal with approval. New Zealand and Australia were the first to accept it as an industry standard, while Canadian winemakers are transitioning more slowly. The proof of the new closure's approval seems certain now, as European producers, like the makers of classic French Chablis, begin to retool their traditional bottling lines.