After reading the Wine Help thread and GB's observation about more wines being produced with screw caps instead of corks, I came across this article:
Wine bottles with a new twist
By Sam Gugino
Special to MSN
Something screwy is happening in the wine world. Increasingly, the sound of a cork being popped out of a wine bottle is being replaced by the crackle of a screw cap being undone.
More than 120,000 screw-capped wine bottles from Cypress winery in San Jose, Calif., were released in May of this year. Bonny Doon Vineyard in Santa Cruz, Calif., which exhorts visitors to its Web site to "save trees, spurn cork," hopes to have 98 percent of its table wines sealed by screw caps by the end of this year.
While most wines with screw caps are popularly priced, some expensive wines have screw caps. Plumpjack Winery in California's Napa Valley shocked the wine world in 1999 when it bottled half of its 1997 Reserve Cabernet Sauvignon in screw caps and sold that wine for $145 — $10 more the other half sealed with corks.
"We've gotten so technologically advanced in the winery, but corks are a 200- to 300-year-old technology," says John Conover, general manager of Plumpjack.
Corks and screws
What's wrong with corks? The biggest problem is cork taint — the result of a naturally occurring chemical contaminant (2,4,6-trichloroanisole, commonly known as TCA) nurtured by cork that can spoil wine. A wine afflicted with cork taint is said to be "corked." Though TCA poses no health risk, "corked" wines can smell like moldy cardboard or a dank basement. Exactly how prevalent TCA is in wine is a matter of dispute. Some suggest it affects less than 5 percent of wines. However, a four-year study done by The Hogue Cellars of Prosser, Wash., (which will seal 70 percent of its 2004 vintage with screw caps) found that 17.6 percent of wines tested had it. Andrew L. Waterhouse, a professor in the Department of Viticulture and Enology at the University of California at Davis, puts the figure between 5 and 10 percent.
Wines sealed with screw caps prevent TCA. So do synthetic corks. But synthetic corks don't create as tight a seal as screw caps do, or as natural corks do, for that matter. The Hogue study, released in June, examined the effect of five different closures on its wines. In addition to preventing cork taint, screw-cap closures were proven to hold fruit and maintain freshness more effectively than natural and synthetic corks. Hogue uses the best-known screw caps, Stelvin
, made by the French company Pechiney Capsules, which has a factory in California.
"The reason we prefer Stelvin screw caps over synthetic corks is that synthetic corks allowed too much oxygen into the bottle. Screw caps allow less oxygen in and are consistent in the amount of oxygen," says David Forsyth, director of winemaking at Hogue. "After two years you could see the difference. Synthetics tasted tired, especially the whites."
The Hogue study confirmed the findings of an Australian Wine Research Institute study on all wine closures published in 2001. It looked at white wines after 20 months in the bottle and found that wines were better preserved with screw caps than synthetic or natural corks. "It's the most comprehensive study to date," Waterhouse says. "But while the data are very clear, studies on screw caps are still limited."
Under the cap
The Australians deserve much of the credit for helping pioneer the use of screw-cap closures for the past 30 years. The real breakthrough came when 15 Riesling winemakers in Australia's Clare Valley decided to bottle their 2000 vintage with screw caps. This effort encouraged other winemakers in Australia and elsewhere to follow suit. Four years ago, less than 1 percent of New Zealand wine was bottled under screw cap. That figure is expected to zoom to 90 percent by the end of 2005.
In addition to preventing cork taint and keeping wines fresher and more consistent, screw caps are more user-friendly than corks. For example, wines can be cellared standing up (as opposed to wines with corks that must lie on their sides to keep corks moist). Opening a bottle is a lot easier too. Just twist to break the seal instead of fumbling with a corkscrew and risking a broken cork, or one that gets shoved down into the bottle. Resealing the bottle is also easier.
While screw caps appear to have no downside, some people are wary about how well they preserve red wines. Yet, after five years in the bottle, both the cork- and screw-cap-sealed 1997 Plumpjack Cabernets "aged identically" and "look and taste identical," according to Conover. A 2003 report authored by Australian wine writer Tyson Stelzer declared that screw caps were actually superior to corks in preserving red wines.
Still, many consumers associate screw caps with cheaper wines. "There is a perception in the United States that the screw cap is a low-class closure," Waterhouse says. Others say screw caps take the mystique out of wine. However, Conover says "there's no mystique in a cork-tainted wine."
Sam Gugino is the Tastes columnist for Wine Spectator magazine and author of "Cooking to Beat the Clock." He can be reached through his Web site, www.samcooks.com.