Beaulieu Vineyard, one of Napa Valley's most prominent wineries, has confirmed that many of its red wines from recent vintages suffer from a moldy, musty flavor caused by high levels of 2,4,6-trichloroanisole (TCA), the chemical compound also responsible for off flavors in corky wines. The problem could affect as many as several hundred thousand cases of wine.
BV winemaker Joel Aiken and Greg Fowler, the winery's senior vice president of winemaking, acknowledged that the winery has TCA contamination. Aiken said it appeared that most of the red wines made from 1997 to 1999 had some level of TCA taint. BV's white wines apparently aren't affected. (While TCA can mar the flavor of wines, it poses no health hazards.)
"We've wondered in our tastings why we've had so many corky wines," said Aiken. "Now we know the reason."
BV produces more than 1 million cases of wine per year. The winery is best known for its prestigious Cabernet Sauvignon Georges de Latour Private Reserve, whose 1998 vintage was released at $100 a bottle. Now BV faces two daunting challenges: how to deal with the tainted wines and how to eradicate the problem from its cellars and future wines.
Noticeable flaws were first discovered by Wine Spectator during regular blind tastings in its Napa office. Over the past three years, dozens of BV wines (mingled with flights of other California red wines) showed a musty, wet cement character. Suspecting that the problem extended beyond a few faulty corks, Wine Spectator decided to have some of those BV wines tested by an independent laboratory, which confirmed that those wines had TCA taint.
Wine Spectator's tests were administered by ETS Laboratories in St. Helena. ETS runs one of the most advanced wine analysis laboratories in the world and is a leading diagnostician for California wineries, specializing in identifying TCA and other wine defects. ETS did not know the identities of any of the wines tested.
The first tests took place in May. To confirm the results of the blind tastings, Wine Spectator submitted two BV red wines to ETS. Both showed elevated levels of TCA. In subsequent trials in August and early September, 38 wines were submitted for testing, including bottles from some of the best-known producers in California, Washington, Europe and Australia. With the exception of three wines, the non-BV wines showed less than 1 part per trillion (ppt) of TCA.
However, all 15 BV wines submitted had elevated levels of TCA; the bottles ranged from 1.3 to 4.6 ppt, with an average level of 2.7 ppt. Most of the BV wines tested were from the 1999 vintage, including the '99 Private Reserve, which had a 3.7 ppt TCA level. In addition, four of the bottles showed the presence of a specific form of TCA associated primarily with wood products that have been treated with certain preservatives. Such chemically treated wood has been linked to TCA taint in other wineries.
These results suggest that BV's problem was not isolated to a few bad corks, but may have resulted from contamination in the winery. In the past decade, there have been reports of TCA problems in cellars elsewhere in the wine industry, such as in California, Italy and France.
There is no legal standard for acceptable TCA levels in wine. Experts say people vary widely in their ability to perceive and to identify TCA (and other elements) in wine. While some cork producers claim that levels of 6 or even 10 ppt are acceptable, research in Europe and at the University of California, Davis, indicates that some tasters can detect TCA at levels between 1 and 2 ppt, and a rare few can perceive it at even lower levels.
Officials at ETS said TCA taint becomes more readily recognized at 2 to 4 ppt. People with higher threshold levels may perceive the taint as an off flavor without being able to identify it as TCA. In some cases TCA taint will merely rob a wine of its flavor without imparting a noticeable defect. This can cause people to be disappointed in a wine without being able to pinpoint the specific cause.
In August, Wine Spectator shared the results of the ETS tests with BV winemaker Joel Aiken. He said that the winery was aware of high levels of corkiness in its wines, but assumed that the cause was isolated to individual tainted corks. "We've been concerned," he said. "We've seen more corky wines than expected."
Following the meeting with Wine Spectator, BV undertook its own tests to find the source of contamination. "We've tried everything," Fowler said. "We've [tested] water, air and wood, and we are going to get to the bottom of it. We're in a tremendous fact-finding process."
Preliminary results indicate the contamination may come from one specific cellar where most of the winery's top red wines were aged in barrel, Aiken said. He and Fowler said they were "reasonably sure" that this particular cellar was to blame.
In 1998, BV installed a humidifier in that cellar, one of six used to age wines, and it appears to be the source of the TCA. The TCA apparently spread airborne through the cellar and into the wine that was aging in barrels, beginning with the 1997 vintage, Aiken said.
Aiken and Fowler said that despite the positive TCA test readings, no one else had detected off flavors in BV's wines. "We've only had four [consumer] complaints of bad corks in the past year," Fowler said. Aiken noted that it is BV's policy to accept any wine returned for any reason.
TCA in wine is not a health issue, Fowler said, and most of BV's tainted wines are at very low TCA levels, well below the threshold of average tasters.
But he and Aiken vowed to eliminate the cause of the taint. "We'll continue to look at everything," Fowler said.
BV had stopped humidifying the cellar that was suspected of being contaminated, Fowler said, and airborne levels of TCA had dropped sharply. As for the 2000 and 2001 vintages, he and Aiken said they would carefully examine those wines, some of which are still in barrel, and bottle only those wines that had no TCA taint. Fowler said they hope that this is the end of BV's TCA woes.
Levels of TCA Detected in Tests of Selected Wines (in parts per trillion)
|BV Merlot Napa Valley 1999||4.6|
|BV Tapestry Reserve Napa Valley 1998||4.6|
|BV Cabernet Sauvignon Napa Valley Georges de Latour Private Reserve 1999||3.7|
|BV Cabernet Sauvignon Napa Valley 1999||3.4|
|Antinori Chianti Classico 1998||Less than 1.0|
|Beringer Zinfandel Clear Lake 1998||Less than 1.0|
|Chateau Ste. Michelle Cabernet Sauvignon Columbia Valley 1999||Less than 1.0|
|Joseph Drouhin Côte de Beaune 1999||Less than 1.0|
|Kendall-Jackson Cabernet Sauvignon Vintners Reserve 1999||Less than 1.0|
|Robert Mondavi Pinot Noir Carneros 2000||Less than 1.0|
|Rosemount Estate Pinot Noir 2001||Less than 1.0|
|Torres Penedès Sangre de Toro 2000||Less than 1.0|
Source: ETS Laboratories, St. Helena, Calif.