Subscriber login Close [x]
remember me
You are not logged in.


Published:  23 July, 2008

By Jamie Goode

Gallo, one of the world's largest wine companies, has admitted experiencing problems with endemic 2,4,6-tri-chloroanisole (TCA) in its Dry Creek winery in Sonoma, following an alert raised by the tasting panel of US wine magazine Wine Spectator. The magazine's tasters noted off-flavours consistent with TCA in a large number of Gallo wines and sent two bottles of each of 10 wines off for testing by ETS Laboratories. All 20 bottles had detectable TCA levels, with an average concentration of 3 parts per trillion (ppt). TCA is the compound responsible for the musty flavours in wine that result from cork taint, which affects approximately 5% of all wines sealed with corks. However, if a large proportion of wines from one winery show detectable levels of TCA, this suggests the source of contamination is the winery itself. Gallo commissioned ETS to run tests in its Dry Creek winery, the results of which showed that this was indeed the case. Dry Creek winery produces some two million cases of wine annually, including many of Gallo's flagship Sonoma labels. Dr Mary Wagner, Gallo's chief technology officer, was keen to downplay the scale of the contamination. In our Sonoma cellars, a random lot of barrels of wine averaged 1.9 ppt,' she told Harpers. These levels of TCA are so minute that, typically, only a few sophisticated palates can detect it. Note that 1 ppt is equivalent to 1 second in 320 centuries.' Will Gallo withdraw any bottles for sale or destroy any wine? No. TCA is not a health issue and it is almost never a quality issue,' said Dr Wagner. Perception of minute levels of TCA in the [Wine Spectator] article is not realistic for the consuming public.' It is well documented that individuals differ in their sensitivity to TCA. To be able to recognise levels as low as 2 ppt, it is likely that a taster would need to have high natural sensitivity coupled with sensory training. Gallo isn't the first US winery to experience these problems. Boutique winery Hanzell discovered TCA in its winery last year, in response to another alert from the Wine Spectator tasting panel. Hanzell immediately stopped sales and abandoned its old winery, but following extensive consumer studies they have decided to continue selling their 2000 Chardonnay and 1999 Pinot Noir, the two wines affected.