How a canine wine squad combats cork taint in California

Did you know there’s a canine wine squad that combats TCA? The technical name for TCA is 2,4,6-trichloroanisole, but it’s more commonly known as “cork taint.”

Dogs are often employed for sniffing out drugs, but now they’re being trained to detect this compound that makes wine smell and taste like wet cardboard or cement.

For their first trip to the United States, Moro, a golden retriever, and his colleague Zamba, a black Labrador, recently traveled from Santiago, Chile to California to reveal their TCA-detecting prowess.

Geyserville’s Trentadue Winery hosted a recent demonstration and both dogs aced the test. Two small square blocks infused with TCA were placed among the barrels at the winery. Moro used his paw to point them out, while Zamba’s nose was practically glued to them.

“The dogs can pick up smells at .2 nanograms per liter, while people can only detect aromas at 2,” explained Juan Carlos, the commercial director at TN Coopers, the originator of the dog-sniffing project. A nanogram is minuscule, a billionth of a gram. “These dogs can detect up to 10 different compounds of aromas,” Carlos said.

The dogs are part of training project that originated 10 years ago at TN Coopers. Headquartered in Santiago, the cooperage has an office in Sonoma as well as others in Argentina, Italy and South Africa. Carlos said the cooperage is working with 40 wineries in Chile and 25 wineries in Argentina.

However, it will be hard to gauge the use of these four-legged detectives in Northern California because wineries have non-disclosure agreements with the cooperage.

The problem with TCA, Carlos said, is that it can turn up anywhere there’s moisture - on hoses, in barrels and on corks. A traditional method of testing for the compounds involves bentonite, an absorbent clay. But that can’t pinpoint the source or the extent of the contamination, Carlos said.

“The dogs can sniff out exactly where the problem is,” he said. “In Santiago, if the dogs point to a pallet or barrels, we send samples for analysis right away, and the dogs have always been right.”

While TCA poses no health concerns for wine drinkers, it can damage a wine’s image. The solution can be costly.

In 2003 Hanzell Vineyards in Sonoma Valley spent $1 million to resolve its TCA contamination, according to Jean Arnold Sessions, president of the winery at the time. St. Helena-based ETS Laboratories found traces of TCA in the winery’s 2000 Chardonnay.

“How the TCA got into the wine is still a bit of a smoking gun,” Arnold Sessions said. “But the chlorine used was the culprit. We found TCA in the drain and in the hoses.”

The contamination was found in an old case storage area. But the new production facility, which was already in progress of being built, completely remedied the problem with quality control measures added.

“You have to manage it with a zero tolerance but you can’t eliminate it,” Arnold Sessions said. “TCA is naturally occurring in a man-made world.”

The vintners of Freeman Vineyards in Sebastopol - Ken and Akiko Freeman - also take great measures to prevent TCA contamination. They steam and pressure wash incoming barrels and pay extra to have each and every cork tested.

“What we’re afraid of most with TCA is that people who don’t know our wine will just think it doesn’t taste good,” said Akiko, the winemaker.

The Freemans said they hadn’t heard about the TCA-sniffing dogs, but Ken said it could be a viable option for those concerned about a TCA contamination.

“It makes sense,” Ken said. “If there’s anything that can eradicate the problem or anything that can help identify it, it’s a positive.”

Wine writer Peg Melnik can be reached at peg.melnik@pressdemocrat.com or 707-521-5310.