Gallo of Sonoma has confirmed that its Dry Creek Valley winery and cellar, along with many of its wines, have been tainted by TCA (2,4,6 trichloranisole), the same chemical compound responsible for off flavors in corky wines.
Gallo, the second-largest wine company in the United States, produces 90 different individual bottlings in its Dry Creek facility, totaling nearly two million cases. Those include a variety of labels, such as the Gallo of Sonoma, Rancho Zabaco, Frei Brothers, MacMurray Ranch and Marcelina brands.
Peter Vella, vice president of winemaking for Gallo, said tests done for Gallo by ETS Laboratories in St. Helena, Calif., a leading wine-analysis laboratory, found TCA in several Gallo wines. Tests of four bottled wines showed levels that ranged from 2.5 parts per trillion (ppt) in the 1999 Gallo of Sonoma Frei Ranch Vineyard Cabernet Sauvignon to 5.6 ppt in the 2000 Louis Martini Napa Valley Cabernet. Gallo claims that the levels of TCA are too low for most consumers to notice. TCA poses no health hazards.
Vella said the winery has been putting "tremendous energy" into eradicating TCA from its cellar and warned that TCA is an industrywide concern. Already, three other wineries in California -- Beaulieu Vineyard, Chalone and Hanzell -- have acknowledged finding TCA in their cellars and wines.
Gallo suspects that chlorine-based products that had been used to clean the winery may have been responsible for the spread of TCA. When chlorine comes in contact with wine and mold, the combination can create TCA. "I think if you have to pinpoint [a cause], it's the chlorine," Vella said. "This is a terrible price to pay for being clean."
The TCA taint in Gallo's wines was first discovered in Wine Spectator blind tastings beginning in mid-2002; since then, 35 of 75 Gallo-made wines that were tasted displayed off flavors consistent with TCA. TCA can impart musty flavors or an earthy, chalky bitterness, or make wine taste green and stripped of flavor. People vary widely in their ability to perceive and identify TCA in wine, but those who are sensitive to it can detect it at levels as low as 1 ppt.
Seeking scientific confirmation of these blind-tasting results, Wine Spectator paid to have 10 individual bottlings tested, submitting two bottles of each wine. Tests administered in 2003 by ETS (which did not know the identity of the wines) showed that all 20 Gallo-made wines submitted had TCA, with an average level of 3 ppt. Wine Spectator informed Gallo about the high incidence of TCA in its wines, which raised questions about whether it might be endemic to the winery itself, rather than isolated instances of corked or otherwise tainted wines.
Vella said after last year's story in Wine Spectator about TCA problems in BV's wines and cellars, Gallo hired ETS to conduct tests of its cellar and retained its director, Gordon Burns, to help head up a committee to determine the cause. Those tests showed low levels of TCA in its Dry Creek Valley cellar and, later, in its wines as well. Vella said the winery also stopped using chlorine as a cleaning agent late last year.
As of this October, said Vella, new tests showed considerably lower levels of TCA in the cellar, with levels reported at 0.8 to 1.2 ppt, about half of what was measured earlier in the year. However, their tests showed TCA levels in wines held in barrels and tanks at an average of about 1.9 ppt.
"Will we ever get it to zero? I don't know, but that's the goal," Vella said. "We have taken all steps to reduce it."
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