WINE:New ways of sealing wine bottles will reduce the number of corked or oxidised bottles that arrive on our tables, writes Pat Carroll
IF, EVERY TIME you came home from the supermarket, between two and five per cent of what you'd bought was rotten, damaged or generally unusable, you'd be annoyed. Yet every time we buy a bottle of wine sealed with a cork, we take the risk of the wine being "off". Older bottles, having been in contact with the cork for longer, are more susceptible than younger ones, but cork taint can affect all wines. Estimates vary on the proportion of corked wine, but most commentators agree that it runs from two to five (some say 10) per cent.
The main culprit in corked wine is trichloranisole (TCA), a chemical that results from contaminated corks. The wine will smell musty and will be sour, with flat (or no) fruit. Badly corked wine is foul, undrinkable stuff, but cork taint can also affect wine at a lower level, making the wine dull and unappealing.
Another problem that can affect many wines is oxidisation. If the seal between the cork and the glass bottle is less than perfect or the cork is too porous, too much oxygen gets into the bottle. This affects older wines especially; whites turn a deep brownish yellow, with a vaguely caramel taste and no fruit flavour. In a restaurant, wine can be sent back, but no one relishes the prospect of doing this and it can lead to difficulties if the sommelier doesn't agree with the customer. Wine bought in a local off-licence can be returned easily, but that's not the case if it was a precious bottle bought abroad, or a gift.
More and more producers, especially in the New World, are turning to alternative closures such as screwcaps (Stelvin), plastic corks or even glass stoppers. Ironically, screwcaps were invented in France, though the first country to embrace them wholeheartedly was Australia. In 2000, a group of producers from the Clare Valley decided to bottle all their Rieslings under screwcap. Consumers appreciated the reliability of wines with the new closures, and screwcaps soon spread to New Zealand, where its signature wine, Sauvignon Blanc, benefited from a closure that ensured the wine's freshness and vitality.
It was a risky course of action, since consumers at that time associated screwcaps with the cheapest and nastiest of wines, but it was ultimately successful. With the help of explanatory neck labels and good PR, consumers began to understand that screwcaps were all about maintaining quality. Cork is now very much the exception for both countries, for both white and (increasingly) red wines.
Plastic corks, widely used in cheaper wines, have the advantage of being free from contamination, but they can be hard to extract and it's often impossible to reseal the bottle. They are also unsuitable for wines that will be aged. Glass stoppers, which are popular in Germany, are an interesting development. Unlike plastic corks, they won't affect the taste of the wine over a long period, they can be recycled and they're aesthetically pleasing.
Could we be buying wine with beer bottle tops in the future? Crown caps (beer bottle caps) are technically suitable for wine bottles - Champagne bottles are sealed with them when maturing in cellars - but consumer resistance would be high, to put it mildly. But things change - milk once came in glass bottles. In efforts to reduce their carbon footprints, Wolf Blass and Boisset have both released wines in plastic bottles. Are screwcaps the Holy Grail of wine closures? There have been complaints about reduction, where wines under screwcap have had unpleasant odours caused by sulphides (smelling of rotten eggs, burnt match or rubber), but these problems can be avoided by improved winemaking techniques.
Another objection to screwcaps is that the romance has gone: anyone brought up with cork will miss the ritual pulling of the cork and the pop, but they certainly won't miss the ritual of returning bad wine or pouring the contents of a €30 bottle of wine down the sink.
The case for screwcapping young wines, red or white, is very strong, but it's still too soon to know how red wines will age under screwcap. Opinions are divided. One issue is oxygen. Cork allows some oxygen to pass through to the contents in the bottle, which is thought to have a beneficial effect as the wine ages (but can lead to problems if too much oxygen gets through).
Some winemakers believe that wine doesn't need oxygen to age properly. David Gleave (Master of Wine) of Liberty Wines says: "Screwcaps permit a small amount of oxygen ingress into a bottle, about the same amount as a good cork. The difference is that the screwcap closure is consistent, whereas every cork is different."
The Portuguese cork industry is fighting back on two fronts. A well-funded PR campaign has raised concerns about the environmental damage that would ensue if cork forests disappeared. Money is also being spent on efforts to eradicate cork taint. CTCOR, the Portuguese Cork Technology Centre, researches methods of removing TCA from corks and claims that these processes can reduce the level of taint to a minimum. The problem is not yet solved, however.
European producers, especially the French, are beginning to see the light. It's commonplace to find vin de pays and less expensive AC wines with screwcaps. Two producers, Michel Laroche and Jean-Claude Boisset, are even bottling Grand Cru wines under screwcap. Winemaker Gréory Patriat of Boisset switched to screwcap after attending a tasting in France in 2004. He tasted the same wine, a 1966 Mercurey red, sealed under both cork and screwcap. The wine under cork, as you might expect from a 38-year-old Mercurey, was dead. The wine under screwcap was still fresh and alive.
Italian regulations are much stickier: non-cork closures are prohibited for all DOCG wines and many DOC wines such as Chianti. Earlier this year, Italian producer Allegrini decided not to use the Valpolicella Classico classification, which requires corks, bottling the wine under screwcap as humbler DOC Valpolicella. Winemaker Franco Allegrini explains: "The closure is more important to us than the denomination." He believes that screwcap closures retain freshness in the wine. From the 2005 vintage, Paolo de Marchi's Supertuscan Isole e Olena Cepparello will be sealed under screwcap using the IGT classification. If you've ever had difficulty in opening a screwcapped bottle (and it does happen), there is a foolproof way. Instead of twisting the top off, take the bottle in one hand, grasp the entire seal with the other hand, and twist the bottle towards you until the seal clicks. The top will then come off easily.
Unless advances in technology substantially decrease rates of contamination in bottles using corks, its days are numbered for all but the most expensive, traditionally produced wines. There's no doubt we'll miss pulling the cork, but think of the advantages - no need for corkscrews, bottles can be easily resealed, no more corks broken in bottles - and no need to store bottles on their sides. Best of all, wine will arrive in your glass the way the winemaker intended it to - perfectly preserved and in great condition.
Pat Carroll is co-editor of The Best of Wine in Ireland 2008and part-time manager in Gibney's Off-Licence, Malahide. John Wilson is on leave.