Tuesday, February 01, 2005

1 February 2005: What about "corked" wineries?

Can a winery be "corked?"

TCA (trichloroanasol), the compound that causes "cork taint," or "corked" wine, is found in other places...wineries -- especially wineries with older wooden equipment. You see, TCA is created by an interaction between bacteria and a phenolic compound called trichlorophenol. Trichlorophenol is found in wood (and cork) that is cleaned and sterilized with chlorine. That interaction produces TCA. Evidently, older wooden structures in wineries that have been repeatedly disinfected with chlorine-based solutions are prone to be infected with the same bacteria that causes cork taint. The result is that the winery itself can be "corked" -- and TCA can get into the wine before it is even bottled!

About ten years ago Beaulieu Vineyards in Napa Valley was one of the notable wineries that had to confront this problem when large batches of their wines were found to be "corked." The winery, full of old wooden structures like barrel-stacking frames was checked for TCA and found to have significant levels in the winery's atmosphere. Removal of the suspect structures and implements solved the problem. Wineries, especially older ones with lots of wooden equipment, are, or at least should be, constantly monitoring for the existence of TCA -- many have, or are in the process of, removing all wooden structures and equipment, replacing them with different materials. By the way, oak barrels aren't cleaned with chlorine, so they're safe -- for now...

The good news is, unlike phylloxera or Pierce's disease, getting rid of TCA is possible, and the next generation of wine drinkers won't have to worry about it.


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