PORTLAND, Ore. - It's the main event in the battle over how to close a bottle of wine: Cork vs. screw cap. To some, it's a matter of style. To others, it's an issue of quality. And now, it's a question of what is best for the environment.
Cork was the standard closure for ages. But winemakers began moving to alternatives in the past decade because of problems with cork that were ruining wines. Screw caps became a popular option and are now seen topping many fine wines, such as some bottles from Napa's PlumpJack winery that sell for $100 or more.
But some winemakers and environmental groups are urging wineries to return to basics -- saying cork is the best choice for the environment.
"This is one of those things where something we have done for years that is traditional is actually the sustainable choice," said Jim Bernau, owner and founder of Willamette Valley Vineyards in Turner. "How often can you say that for anything we've done in the past 50 to 100 years?"
Cork is a renewable material -- made from the fiber stripped from cork trees that can then regrow. The largest and most profitable use of this harvested cork worldwide is for wine stoppers.
Several environmental groups say the growing popularity of alternatives like screw caps are threatening Mediterranean cork forests, where cork is mainly grown. Cork oak covers about 6.7 million acres in the region and provides income for more than 100,000 people, according to the World Wildlife Fund.
Cork forests are predominantly privately owned, which puts them at greater risk for neglect or sale for development if the popularity of cork lessens.
Cork producers say they have seen the overall production of wine stoppers drop in the past decade. And last year, The World Wildlife Fund estimated that if winemakers continue their move away from cork, three-quarters of the western Mediterranean's cork oak forests could be lost within the decade, threatening jobs and ecosystems.
The Rainforest Alliance recently jumped into the fray, offering a certification system for wineries to verify that their cork comes from cork forests that meet Forest Steward Council's social, economic and environmental standards -- lending assurance to winemakers and consumers that the cork was properly handled.
The issue is complicated for winemakers, who are often swayed by issues of sustainability but have been burned by cork's quality issues in the past.
The primary problem that drove vintners away from cork was "tainting" or "corking." Cork taint is actually a chemical compound called TCA, which results from an interaction of mold, chlorine and other organic compounds that produce a moldy or musty smell and flavor that makes wine undrinkable.
Estimates vary, but some wineries say as much as 15 percent of their wine has been tainted in the past. Screw caps, by comparison, don't have issues with tainting and are a fraction of the cost. However, they are usually made from nonrenewable material -- typically aluminum with a plastic insert. That also makes them difficult to recycle.
The debate is particularly hot in Oregon, where sustainability is a badge of honor among winemakers. Several wineries boast the use of solar panels, biodiesel-fueled tractors and organic farming practices. There are salmon-safe wines, which ensure the winemakers' practices don't harm water that feeds into salmon waterways. And 16 Oregon wineries recently pledged to go carbon-neutral in the next 18 months.
"I think all of us are paying a lot more attention to (the environment)," said Bernau, whose winery got the first Rainforest Alliance sustainable cork certification this year. "When you start seeing the temperature change in your vineyard, you start to pay more attention to it."
But environmental concerns are not enough to sway some winemakers.
Willie Lunn, senior winemaker with Argyle Winery in Dundee, Ore., said his business became solely screw caps in 2002 and will be staying put for the time being.
"The reason we went to screw cap was purely a quality point of view," Lunn said. "For us, wine making is about the wine."
And as consumers' resistance to screw caps or romantic ties to cork have died down some, screw caps seem to have strengthened their footing. Winemakers say they are even seeing some consumers ask for screw caps for ease of use.
The cork industry did react as winemakers fled to other options, cleaning up its production and screening process to cut down on taint, such as using better wood and quicker drying methods. The world's largest cork maker, Amorim, said it has spent several million dollars on its upgrades.
That's what won Bernau, whose winery once successfully sued its cork maker over taint, back to cork. He says the level of taint has been dramatically reduced with some of the cork industry's new innovations.
But it is still unresolved for some.
"It's a very complex issue. I don't have a problem with cork," said Dave Paige, winemaker at Adelsheim Vineyard in Newberg, Ore. "I'm just acknowledging that sooner or later someone is going to come up with something relative to cork that is equal in quality, acceptable to the public and recyclable. Then the conversation is over."
