Here's my proposal for the quandary over wine bottle closures: For wines meant to be drunk in a year or two, use screw caps; save the best-quality cork for the top wines with aging potential.
I am concerned about the prospect that high-quality wines, wines capable of developing 10 or 20 years in the bottle, may be finished with twist-offs. That concern arises, in part, from a recent tasting of Chablis from Domaine Laroche.
Beginning with the 2003 vintage, Domaine Laroche will ship all its wines to the United States with screw caps. This is a bold move; not only will the entry-level Chablis St.-Martin sport a screw cap, but the premiers and grands crus, too.
Michel Laroche is president and main shareholder of Domaine Laroche, an important wine producer in Chablis. He began experimenting with screw caps in 2001 after opening 40 bottles of his flagship Chablis Les Blanchots Réserve de l'Obédience 2001 one day and finding "40 different wines." He was referring to bottle variation, a phenomenon he blamed on variable oxidation from the cork closures.
"As winemakers, we try to avoid oxidation," explained Laroche, 59. "Even without TCA [the chemical that can produce moldy flavors via tainted corks], a cork is not neutral. With a fresh, delicate style of wine like Chablis, the cork marks it quickly, like a little spot on a white shirt."
Laroche cited tests performed by Peter Godden, manager of industry services for the Australian Wine Research Institute, indicating that after three years in the bottle wines under screw cap have 30 to 50 times less dissolved oxygen than their counterparts finished with cork.
To demonstrate the differences between screw caps and cork, Laroche conducted a single-blind tasting in New York this past May. Seven pairs of Chablis were presented. Each pairing was the same wine, ranging from Chablis to grand cru, one with screw cap and one with cork. All were from the 2002 vintage except one pair from 2001.
All the wines were bottled at the same time. Because they were young, the differences were subtle, but the wines under screw cap were generally fresher and less evolved. (Laroche claims that after two and three years the differences are more pronounced.)
Ironically, I preferred the wines finished with cork in four of seven instances, with one tie. They were richer in texture, rounder and longer on the finish.
This raises an interesting issue. What, if any, changes occur when a winery decides to bottle its wines with screw caps?
Despite the obvious benefits, switching to screw cap is not simply a matter of changing your bottles and bottling line. Adjustments have to be made in the maturation and handling of wines destined for screw cap closures. More importantly, the change to screw caps can affect the evolution of the wine in bottle, in turn forcing people to reconsider their judgments about how wines age and when to drink them.
Laroche pointed out that wines finished with screw caps absorb about 10 times less free sulfur dioxide than wines with corks. This is due to less oxygen present to bind with the SO2. In other words, wines under screw caps are in a more reductive state. Thus, winemakers must adjust their SO2 levels to compensate for this.
To adjust for the slower oxidation in the bottle, Laroche said that the wines in barrel must mature for an additional one or two months prior to bottling. Those in stainless steel tanks will undergo more micro-oxygenation, since tanks negate any oxygen exchange. These adjustments allow for the right level of oxidation when the wine is bottled.
The biggest shift must take place on the demand side of the equation. There must be a cultural change in consumers' perception of wines under screw cap. Though Laroche is taking this bold step in the American market, the wines sold France will continue to be finished with cork.
"We are only speaking of a cultural problem. Less risk of oxidation and cork taint seems to be a great advantage that people understand. I know it's going to take some years before it will become popular, but someone has to start. I like new challenges," explained Laroche.
Perhaps Americans are more open-minded when it comes to screw caps, but will collectors and restaurants buy grand cru wines capable of developing over 20 years or more without cork closures?
Consider storage: Screw-cap bottles are best stored upright. Bottles lying down put pressure on the seal. If compromised, this can lead to oxidation. If the tops of bottles are knocked, this can also break the seal and cause oxidation.
Furthermore, the wines presumably will develop more slowly under screw cap. As consumers and wine lovers, we must recalibrate the aging process of our wines to accommodate this different aging curve. It may take a generation to fully accept these changes. I myself am not quite ready.