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Inquiring Winemaker TIM P A T TERSON Ignoble Rot in California threat in—you guessed it—Europe for many years before it hit California's North Coast, at which point it prompted quarantine and lots of research funding. Botrytis was another one of these far-away concerns, something growers worried about in France or Oregon or upstate New York; some folks in California were even frustrated about the relative absence of the "good" botrytis, the kind that makes heavenly dessert wines. Then came the 2011 harvest. Welcome to the botrytis club. The loony weather in 2011 made for a tougher year in Or- W egon; for many people in the California industry, this was completely unexplored territory, something they had only read about in a long-forgotten plant pathol- ogy textbook but never had to root out of their own premium Cabernet Sauvignon. Growers sprayed and dropped fruit and shook rotten berries off of vines, yet some still watched whole vineyards succumb. Wineries sorted and sorted and sorted, put the grapes through Flash Détente and doused them with tannins and SO2 , doing everything they could to vinify their ways around the problem. Most of the sleep has been lost over a nasty little enzyme called laccase, donated by botrytis, which can turn both whites and reds an unappetiz- ing oxidized brown. Chances are good that there's still a lot hen the glassy-winged sharpshooter was just a problem in Florida, it wasn't a big issue for the wine industry because, well, they don't make millions of cases of Chardonnay in Florida. Once it hit California, the little bug became a big issue. The European grapevine moth was a constant Highlights • Botrytis rot, a staple problem in Europe and cooler, wetter parts of the United States, made major inroads into Califor- nia in 2011. • Winemakers are still struggling with the after-effects, particularly the presence of laccase, an enzyme responsible for oxidation and browning. • Rigorous understanding of botrytis and laccase is still spotty. of the stuff floating around in tanks and barrels as you read this, just waiting for a fresh blast of oxygen. Since botrytis and its evil spawn have been around forever, and the basic chemistry of the reactions has been understood for de- cades, it's appropriate to ask how much we know about how lac- case operates and how we can best get rid of it. The answer: not nearly enough. Laccase primer A quick tour of laccase highlights the spotty state of our knowl- edge in this area. As Donald Rumsfeld might put it, we have some 82 Wines & Vines MAY 2012 Not all botrytis is visible on the outside of clusters (as seen above), making it easy to sneak into the winery and be fermented. known-knowns, some known-unknowns and some unknown-unknowns. The fungus Botrytis cinerea makes sev- eral unpleasant contributions to grape ber- ries and juice: moldy aromatic compounds, toxins that can impede yeast fermentation activity, beta-glucans (a type of polysac- charide that can make clarifying wine dif- ficult), reduction of available nitrogen and the laccase enzyme. Right away, we come to our first known-unknown: There is no clearly established correlation between the level of botrytis infection and the amount of laccase produced. Some of this variation may be due to the particular strain of botrytis involved, some to other factors influencing the metabolism of the fungus. (Ironically David Paige, winemaker at Adelsheim Vineyard in the Willamette Valley, says that while Oregon has more than its share of the "bad" botrytis attacking its Pinot Noir and Chardonnay, it lacks the "good" botrytis strains needed for top- notch late-harvest wines.) And just as there are strains of botrytis, there may be many laccases (it's the name for a whole family of copper-containing oxidative enzymes) with slightly different bad ROB & LISA MEEHAN