A Chilean winery has joined the unfortunate ranks of wine producers in France and California who are battling contamination in their wine cellars, as it works to eliminate a rogue chemical that imparts musty, dry flavors to wines.
Viña Errázuriz, a well-established and highly regarded winery located in the Aconcagua Valley, has admitted that some of its wines contain elevated levels of TBA (2,4,6-tribromoanisole), a nearly identical compound to the more familiar TCA (2,4,6-trichloroanisole), which is known for causing cork taint in wines. Both compounds result in dry, musty odors in wines. Many wineries in France and some in California have spent the last decade dealing with the effects of TCA-related contamination in their cellars, and experts and other winemakers worry that the TBA problem may be spreading in Chile and Argentina.
TBA is typically derived from wood preservatives and flame-retardant paints used in cellar construction. The compound can then spread through a winery; porous materials like plastic hoses are particularly susceptible. TBA has become a problem for wineries in South America because the locally produced materials used to build their cellars contain bromophenols, which can create TBA. (In contrast, the building materials used by French wineries in the 1980s and '90s commonly contained chlorophenols, which can evolve into tetrachloroanisole and pentachloroanisole, which are similar to TCA. Those materials have since been banned.)
"[TBA] is a big problem in Chile and Argentina right now," said Pascal Chatonnet, a Bordeaux-based enologist who consults extensively in both countries. Chatonnet is one of the world's leading experts on TCA and TBA contamination; he is credited with isolating and identifying the cause of TBA after research he conducted in 2004. One of his earlier studies showed that TCA and TBA can be transmitted through the air.
The problem at Errázuriz first came to light when some of its wines repeatedly showed musty, dry flavors in Wine Spectator blind tastings. Subsequent tests conducted by ETS Laboratories in Napa Valley confirmed the presence of TBA in the Viña Errázuriz The Blend Limited Edition Aconcagua Valley 2004, an 800-case lot blend of Cabernet Sauvignon, Syrah, Carmenère, Petit Verdot and Sangiovese. The wine sells for $40 per bottle. ETS measured the presence of TBA at a level of 4.5 parts per trillion (ppt), higher than the 4 ppt considered to be the normal threshold for detection for that compound, according to Chatonnet. There are no health risks to drinking wine tainted by TBA or TCA.
Eduardo Chadwick, owner of Viña Errázuriz, admitted that his winery has had a TBA problem, and said that he is working to correct it. "We had some old wood sectors in the cellar that were potentially giving out TBA," Chadwick said. "We know The Blend is one wine that was bottled with an amount of TBA that could be considered above the normal percentage. Since the 2005 vintage however, we are confident that the wines are now totally clean."
|Errazuriz winemaker Francisco Baettig is now checking for TBA every step of the way.|
Viña Errázuriz winemaker Francisco Baettig noticed the potential for taint soon after joining the winery in 2003. "I realized we could have problems since we used wooden chocks and logs to stack the barrels," said Baettig. "We started to take samples from all kinds of materials in early 2004, and we realized we had some level of contamination. When we checked the wines, we realized that the contamination level was increasing from [vintage] 2002 onward."
The hard part was pinpointing the source of the contamination, Chadwick said. "TBA can be in a single hose, or on some barrel bungs, making it very difficult to find. But once you know what it is and where it is, then it can be dealt with fairly easily."
Identifying TBA as the type of taint has also been difficult for Chilean wineries, as the molecule is so similar to TCA, the more commonly known source of musty odors in wine. According to Eric Herve, a scientist with ETS Laboratories in California, TBA and TCA are "virtually identical" molecules, with the exception that "TBA has bromine atoms where TCA has chlorine atoms."
Chatonnet explained that while many South American wineries realized there was a problem when their wines began to show musty notes, they were testing for TCA instead of realizing they had a different culprit on their hands. (Chatonnet would not disclose the wineries for which he is working.)
"Organoleptically it is very difficult to tell the difference. They are both musty," Chatonnet said. "There is a little more bitterness prevalent on the palate with TBA, but the threshold is also a little higher than TCA--4 parts per trillion for TBA versus 2 to 3 parts per trillion for TCA."
But TBA contamination is a particularly serious problem for infected wineries, since it indicates a problem with the winery facility itself, as opposed to flawed corks or closures on which TCA developed. (In tainted California cellars, the problem is not typically linked to the building materials but to the use of chlorine-based cleaning products, which react with plant-based phenols such as those in corks, to form TCA.)
"TBA wouldn't originate from the cork," said Herve. "Cork can be a vector, if the corks were stored in a TBA-contaminated room. But its presence [in a wine] is more likely a factor of widespread airborne contamination."
Chatonnet agreed. "If TBA is in a wine, it means the winery is probably contaminated."
|Consultant Aurelio Montes says a growing number of wineries are seeking advice on cellar taint.|
"TBA didn't kill me, so I hope it made me stronger," said Hartwig. "I lost a lot of business thanks to that. When you don't know where it's coming from, it's especially frustrating and expensive to deal with. Once I figured out it was coming from the wood beams that separated my barrels, I got underway with solving the problem."
Aurelio Montes, one of Chile's most respected winemakers and consultants, who also works in Argentina, said he has been fielding an increasing number of calls from wineries looking for his help with potential TBA problems. "It's a growing problem," asserted Montes, who also speaks from personal experience. "I started seeing some strange flavors in my own wines three years ago. And after testing, the problem was TBA--not TCA--which was something totally new to us."
Montes said the wines, which were being aged at his older winery facility in Apalta, were from one vintage and in a select number of barrels. To deal with the problem, Montes did not release the wines into the market, threw away the offending barrels and installed an automatic ventilation system that moves 10 times the total air volume in the winery each day.
"We didn't want a problem with our wine in the marketplace--so we dealt with it before they got to market," Montes said. "It takes a pile of money to get rid of [TBA]--and it's a very difficult decision to make, especially if you're a small winery. But you have to make that decision."
Montes also noted that sometimes winemakers have trouble detecting TBA taint problems because they become used to the aroma after working in an infected area for so long.
Other top consultants who work extensively in South America--Paul Hobbs and Alberto Antonini--also said they had faced problems with TBA. "Unfortunately, I've had to deal with this first-hand on several occasions," said Antonini. "I'm now very strict with my clients when it comes to this subject, and I force them to get rid of all the potential sources of contamination. Sometimes the producer doesn't want to do it because it is an expensive decision to make. [But] it is a lot cheaper than damaging your brand."
"The message is there, in capital letters, in red and underlined," said Montes. "You have to attack it--there can be no half measures."