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WINEMAKING is pressed and fermented. "The tough part," says Adelsheim Vineyard's Paige, "is I don't know there's a gold standard for looking at fruit as it comes in and saying I know exactly what to do. It's impractical to test for laccase in real time. You have to go with your gut." The baseline, non-interventionist path for minimizing the im- pact of laccase is reductive winemaking: If the laccase is starved for oxygen, it can't behave badly. This means avoiding skin con- tact for whites as well as cold soaks for reds, early and generous yeast inoculation and short fermentations with strong nutrient support, no extended maceration, rapid settling after fermentation and extreme care to minimize oxygen uptake in pressing, racking, filtration and every other winemaking operation. Although sulfur dioxide does not neutralize laccase, it does scavenge some oxy- gen and thus slow oxidative reactions, so sulfur additions at the crusher are normally a bit higher than usual, and sulfur levels are kept up throughout maturation. Crossing your fingers helps, too. If you know you may have a laccase issue, the first line of intervention is supplement- ing a reductive strategy with tannin addi- tions. This—plus testing by ETS—is basical- ly the regimen that winemaker Amy Aiken of Napa's Meander Wines used on her lots of Cabernet Sauvignon from 2011, and at the moment, she is happy with the results. With a background in plant pathology and in the industry since 1988, she says this was the first time she saw real, live botrytis up close on Cabernet, but some combination of good luck and careful winemaking yielded Cabernet that tests laccase-free. Her Sauvi- gnon Blanc, from a different, botrytis-prone vineyard, has just a touch of botrytis influ- ence, something she likes in that wine. Aaron Pott is a Davis graduate, but he did the tannins, there are a number of variations in surface chemis- try, making some things more reactive than others and producing variation in fining capacity. The AWRI's Coulter agrees, citing the lack of scientific data relative to the question and the lack of cor- relation between laccase activity and total phenolics. In addition to tannin offerings, the AEB Group has carried for sev- eral years an enzyme eradicator, Endozym Antibotrytis, developed by Pascal Biotech, which contains a protease that breaks up laccase, as well as a glucanase that breaks down beta-glucans. The product works best on juice, says Russ Robbins of AEB, since alcohol acts as an inhibitor. "AEB has had this for years," he says, "but no one bothered. Until this year, nobody measured for this stuff. The folks in France and Italy buy it by the bucketful." The knownest-known of all is the one sure-fire method for stop- Tannin additions have worked, but his first major winemaking stint in Bordeaux at Chateau Troplong-Mondot; now he makes his own wine and consults for several wineries in Napa including Blackbird and Seven Stones. Since that French experience made him an old hand at dealing with botrytis and laccase, he says, "I got a lot of calls late last year from the people I learned to make wine from, asking me for help." Although he didn't experience "full-blown" laccase in 2011—the mountain grapes he works with were less affected than valley floor fruit, he says, and Cabernet is fairly resistant—he does counsel quick fermen- tations, no cold soaks, and tannin additions to make up for the phe- nolic material laccase messes up. (Learn more in "Old World Lessons For Winemakers" on page 100.) There is plenty of evidence beyond these two winemakers that tan- nin additions can play a major role in staving off the depredations of laccase—but it's not entirely clear why that is. One school of thought likens tannin additions to fining: tannins hook up with the energetic laccase, polymerize into clumps and precipitate out of solution. An- other school holds that adding fresh tannins makes for a larger pool; some are sacrificed to the laccase, some continue to play the anti- oxidant, color-fixing, structure-giving roles assigned to them. Tannin additions have worked, says Dr. James Osborne, head of the enology extension program at Oregon State University, but "the mechanism isn't well understood. Particularly in red wines, it's hard to pull out a simple answer." Both in the laccase and 86 Wines & Vines MAY 2012 "the mechanism isn't well understood. Particularly in red wines, it's hard to pull out a simple answer." —Dr. James Osborne, Oregon State University ping laccase in its tracks: heat treatment. A few seconds at 140ºF should do the trick, denaturing the laccase (and any other enzyme in the area). Flash pasteurization of finished wine is a common practice in Europe and Australia, but a rath- er small niche in North America. Both Bry- an Tudhope of VA Filtration and Eric Dahl- berg of WineSecrets, two of the major wine rehab services, say that they have fielded inquiries about their heat treatment services in recent months but gotten very few actual customers so far. "I think many people are hoping it will just go away," Dahlberg says. Both companies are also exploring the use of ultrafiltration for removing laccase and perhaps browned pigment as well from white wines. At the front end of processing, users of the increasingly popular Flash Dé- tente technology—thermovinification that pulverizes red skins and effectively sterilizes red and white grape juices up front—may have received an extra bonus this harvest: getting rid of any lurking laccase from the start as part of the package. The use of heat, early or late, remains con- troversial, with many professionals arguing that it produces cooked flavors, alongside sen- sory studies finding little difference in percep- tion. Boulton thinks heat treatment is a well- established technique and that wineries seeing evidence of laccase in samples should skip the tannin additions and raise the temperature. And this just in: Quite a number of the people I talked to re- ported, from their experience or from industry hearsay, that laccase levels in affected wines seemed to be going down over time. The test results in February were looking better than those from November. Maybe this isn't going to be as bad, after all. On the other hand, Russ Robbins points out that the expansion of botrytis territory in 2011 means that there's a solid base of spores out there just waiting for another bout of bad weather to leap back into action. So, the glass may be half brown, or all brown. Either way, wouldn't it be nice to have more confidence and less guesswork in the mix? Tim Patterson is the author of "Home Winemaking for Dummies." He writes about wine and makes his own in Berkeley, Calif. Years of experi- ence as a journalist, combined with a contrarian streak, make him inter- ested in getting to the bottom of wine stories, casting a critical eye on conventional wisdom in the process.