Q: Is it possible to find TCA contamination in a screw cap bottle? —Bill T., Canada
A: Yes, unfortunately. Most wine lovers know 2,4,6-trichloroanisole, the compound commonly called TCA, for the musty off-odors that it produces in bottles whose corks it has infected. But cork is just one vessel for TCA: It can also live in other organic material in a winery, such as barrels, pallets, wood chips and cardboard boxes, and thus can potentially infect any bottle of wine—no matter its closure.
TCA in the presence of wine is generally the result of an interaction between mold and chlorine. Winemakers today are acutely aware of the dangers of chlorine exposure in a winery, but this wasn't always the case. Prior to the 1980s, many wineries used chlorine-based cleaning products, and cork manufacturers often sanitized their product with the chemical. A growing concern over the proliferation of TCA has since led to the widespread end of these practices, and today some winemakers won't even let their wine near paper products, the production of which typically involves chlorine.
Cork, then, should perhaps be the least of the winemaker's worries when it comes to TCA. A bad cork may taint a bottle, but a TCA-ridden winery can infect considerably more wine. That isn't to say that TCA contamination in bottles with twist-off closures is common; in fact, it seems to be rare. But don't be afraid to speak up in a restaurant if you order a twist-off bottle of wine that smells suspicious to you.
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