The Screw-cap industry is so topping expectations – even a Duval-Leroy Champagne is now sealed under screw cap – that its market share has doubles since 2006. Today abut 15 percent of all wines sold around the world have screw-cap closures, up from 8 percent just 3 years ago.
More and more well-known producers are now using screw caps on their best “wines,” says Karine Herrewyn, director of European sales for Alcan Packaging Capsules. “Not only do screw caps guarantee there will be no cork taste, they ensure absolute consistency, with every bottle delivering the same aromas and flavors and aging at the same pace. SEALED WITH CARE
As far back as the early 1970s, Australian Brian Croser, founder of the Petaluma winery in Coonawarra and a pioneering teacher in the chemistry of wine, was telling oenology students about the importance of reduction (varying degrees of the absence of oxygen) in wine making and was advocating use of screw-top closures to preserve fruit quality and protect the wine from the oxidative effects of air. Croser’s approach prompted the Australian producer Penfolds to test screw caps on its white wines. Today the majority of Penfolds’ whites, and increasingly its reds, sport screw-cap closures. Even 20 cases of its renowned Grange have been sealed under screw cap every year since the 2002 vintage.Visionary Australian winemaker and terroir enthusiast Brian Croser, 60, worked at Hardys before founding Petaluma in 1976. An early proponent of the screw cap, Croser has since come to see advantages to cork too. One strike against the screw cap is that aluminum production is a very energy-consuming process.
“There is nothing better for wines meant to be drunk in the short or medium term,” says Peter Gago, Penfolds’ chief winemaker. “But we still don’t know how red wines under screw cap will evolve over 30, 40 or 50 years, although our sense is they should age nicely overall.”
Australia and New Zealand are world leaders, by far, in screw-cap wines. Seventy percent of all Australian wines, and fully 95 percent of all New Zealand wines, are sealed with screw caps.
Apart from Switzerland, Europe has been reluctant to go along with the screw-cap trend. But that appears to be changing. “Osez enfin visser” (roughly, dare to screw), runs the French ad campaign for Stelvin, the brand name for Alcan’s screw caps. “We’re seeing steady growth in almost all regions,” says Herrewyn, “although a majority of French consumers are still baffled by screw caps.” She lists the usual preconceptions: A screw-cap wine is not a good wine, cork is crucial to preserving wine and nothing can replace the satisfying pop of a cork in the ritual of opening a bottle. “But,” Herrewyn observes, “all that’s needed to change the mind of even the most recalcitrant vigneron is a comparison of a few aged wines.”
Even Bordeaux’s venerated Château Margaux is testing the waters.
Grégory Patriat, who oversees vinification for the Burgundy négociant Boisset, is a case in point. “In 2006, we opened some wines Boisset had sealed with screw caps in the 1970s,” he recalls by phone from France. “There was a 1972 Nuits-Saint-Georges, a 1973 Savigny-lès-Beaune and a 1969 Mercurey. I was bowled over by their vitality and the precision of their aromas and flavours compared to wines aged under cork. Right then and there I changed my mind!” Ever since, a portion of all Boisset wines have been bottled with screw caps, including its high-end Chambertin.
SOME FANCY SKIRT
Even Bordeaux’s venerated Château Margaux is testing the waters. In 2004, estate manager Paul Pontallier used screw caps for several cases of the 2002 Pavillon Rouge, the Cru Classé’s second label.
“We did it again in 2005, and included the Pavillon Blanc too,” Pontallier says. “We tested composite closures, synthetic closures and screw caps, comparing each to cork. We wanted to be sure not only that a non-cork closure would deliver superior consistency, but also that the quality would be at least equivalent to that of our current point of reference [wines aged under untainted cork] after several decades. Château Margaux is meant to be a long-lived wine, and we cannot offer customers a product whose quality is not guaranteed.”
But doesn’t a screw cap hurt the image of a prestige wine such as Margaux? Possibly, Pontallier acknowledges, while pointing out that consumers’ perceptions are changing. Meanwhile Alcan Packaging Capsules is now offering “what we call our ‘Lux’ closure that utilizes an insert that eliminates the visible threads,” says Herrewyn. “After the bottle is opened, it looks exactly the same as one that was sealed with a cork. We also offer a variety of optional decorative elements such as embossed printing on the top of the cap or serigraphy on the skirt.”
THE BLAME GAME
Are screw caps, then, the ultimate solution? Not necessarily.
Cork itself is not always responsible for cork taint. Fungicides used to treat wood (framing, palettes and so on) can be present in wineries and can break down into compounds that are responsible for a cork taste. Other risk factors are poor storage conditions and the hygiene of barrels. In combination with moulds that are naturally present in the cellars, these factors can cause the air in the room where the wine is being vinified to become contaminated. As a result, it is possible for wines to have cork taint even though they have never been anywhere near cork stoppers.
Another potential problem, this one directly related to screw caps, is the sulphur compounds that tend to form under reducing conditions and to give wine flavours of rotten egg, onion, sulphur or struck flint. In itself the phenomenon is not new and seems to affect wines sealed under cork as well – but they’re less susceptible because cork allows tiny traces of oxygen into the bottle, usually via imperfect seals between the cork and the bottleneck rather than through the cork.
Pontallier says this is easy to fix. “If the closure is responsible for too much reduction in the wine during bottle-aging, you just have to adjust its oxydo-reduction balance by reducing the quantity of SO2 [sulphur dioxide] or increasing oxygenation during bottling.”
Gago admits to having encountered reductive notes in some of his screw- cap wines, but he, too, argues the problem is simple to solve: The consumer merely has to aerate the wine well, pouring it into a carafe so that the disagreeable notes disappear, he says.
Meanwhile, manufacturers like Alcan are doing their bit by making screw caps with seals of varying degrees of permeability. Some caps now have higher oxygen-transfer properties, in a sense recreating the conditions associated with a cork closure.