The first time I became aware that a tainted cork could ruin a wine was at an outdoor restaurant in the French seaside town of St.-Jean-de-Luz. I was with a young French blue blood named Remy and his American girlfriend. Remy took one sip of our muscadet and spit it out. “Corked,” he announced, using the shorthand term for a wine spoiled by a compound called TCA that infects the cork, typically giving the wine a moldy, wet-cardboard quality. Our waiter countered that perhaps the wine was not “corked”; it merely had a typically earthy taste. Coolly, Remy turned the bottle upside down and emptied it at the waiter’s feet.

A year or so later, in a bistro in the West 40s, I found myself confronting my first corked wine, a beaujolais whose naturally vivid fruitiness had gone nasty. My dubious waiter called the manager, who insisted the wine was fine. “Well, it isn’t,” I insisted. Grudgingly, he removed the bottle but, as I suspected might happen, it remained on the bill at the end of the meal. When the corrected bill arrived, it was disdainfully tossed on the table.

It’s a paradox that as winemaking improves, the problem of tainted corks seems to be getting worse. Paul Altuna, a sommelier at Alain Ducasse at Essex House and formerly of Le Cirque, recently told me that he is finding more, not fewer, wines that are corked – something close to 10% at his restaurant. Presumably, only the best wines are reaching Ducasse (pre-screening means they don’t reach the customer), so that’s a sobering percentage. Most estimates of the proportion of corked wines are in the range of 5% to 10%. “There’s a lot of money in the wine business,” says the sommelier of Montrachet, Troy Kinser, “so if 5 or 8 or 10% of is bad, it’s a huge waste.” And it’s not just average wines, Mr. Kinser notes. “Great wines have gone down the sink here because they’re corked. It’s a shame.”

Can nothing be done to build better corks? Not much, apparently. One limitation is the very naturalness of the product. Corks are made from the bark of mature Iberian oak trees which can only be stripped about once every nine years. The taint of TCA can be picked up anywhere: on the tree itself, during manufacture or storage, or at the winery. So it’s unrealistic to protect against cork taint on every front. What’s most insidious is that even sensitive noses and palates may not pick up low levels of TCA, which don’t render a wine unpalatable, merely unfresh. It’s like having a low-level bug that affects your energy level without actually slowing you down. TCA is such a potent compound that a single drop could throw off the taste of wine filling an Olympic-sized swimming pool. As the general quality of wine improves, it seems, cork taint once hidden under other faults becomes more obvious.

The solution is to switch to other closures: either an artificial cork or a screwcap with a neutral inner lining. The screwcap has long been around on cheap wines, of course. What’s new is how it’s moving up to fine wines, despite resistance from old guard winemakers, especially in Europe. The mantra is that wines “breathe” through the cork, and so can slowly mature, developing “bottle bouquet” and rounding out in flavor. But that’s unproven, and probably a myth. What is being proven – with Australian and New Zealand researchers taking the lead – is that the purity of aromas and flavors in white wines, in particular, is preserved best by screwcap closures. Perusing the wine section of an Auckland supermarket three years ago, I was surprised to see a special new section set aside for wines with screwcaps – an innovation of the New Zealand Screwcap Wine Seal Initiative. In the Clare Valley region of Australia, where riesling is a specialty, every maker of this wine has committed to bottling this variety under screwcap. Reds lag, but the best pinot noir I’ve tasted this year, Felton Road’s Block 5 from New Zealand, was sealed with a screwcap.

American winemakers have been slow to abandon corks for artificial closures. An early exception was Plumpjack, an elite Napa Valley winery, which in 2000 bottled a portion of its current vintage of cabernet sauvignon in screwcap. The winery even charged $10 more for the screwcap bottle ($130) than for the cork-sealed version. Only lately has the screwcap movement in America been picking up steam. Last year, giant R.H. Phillips Winery announced that it would bottle 300,000 cases of new vintage red and whites under a sleek new screw cap called TOPP (Torqued on Pilfer Proof). One turn of the wrist, and the bottle is open. Last spring, Hogue Cellars, another big producer in Washington, announced that a three-year study of different closures has convinced it to switch over to screwcaps.

A plus for screwcaps at home is the ease with which they allow reclosing a bottle before it goes to the fridge. No more pumping with a VacuVin to create an air-free seal. I realized only a week ago how thoroughly I’d adapted to screwcaps when I was chatting with guests while struggling to unscrew the cap on a bottle of Nobilo chardonnay from New Zealand. Only when I looked down did I see that this bottle had actually been closed with a cork!

It’s easy to get used to screwcaps at home, less so at restaurants. The tableside ritual of uncorking a chosen wine is almost as sacred to us as a tea ceremony. Still, wine service is timidly adapting. “Screwcaps still spark a memory of Thunderbird,” says the sommelier at BLT Steak, Brett Feore, who finds as many as three bottles of corked wine a night. “I do think screwcaps are great for young fresh whites,” he says, “as long as they don’t reach the table.” As at most top restaurants, wines at BLT Steak are first presented to guests, then opened, sniffed and, if necessary, tasted at a separate station. “Eliminating cork taint is not the only benefit of screwcaps,” said Eric Zillier, sommelier at Alto, the haute-Italian eatery on Madison Avenue. There’s also the ecological issue. “My understanding is that we have a terrific shortage of quality cork,” he says. “The production of wine is increasing greatly, and there’s no way the trees are going to keep up.”

Wine To Watch For

MAN, a new line of budget wines from South Africa, will hit New York shops in the next few weeks. They’re from Fairview, whose “Goats do Roam” line is already a price leader. I’ve tried the Sauvignon Blanc 2005 and Pinotage 2004, both light-bodied, yet lively. Nothing insipid here at about $8 or less. Also included are chenin blanc, chardonnay, cabernet sauvignon, and shiraz. All screwcapped, of course.