Smoke Taint Video Update
Whether we're out to dinner, lunch, or coffee, or just hanging around our neighborhood, we're lucky our friends love to inquire of the status of our pinot. But after the pleasantries, it seems most folks are cagey and pointedly curious about "that smoke stuff," as in, "what was it that happened to those grapes again?" Ever voyeuristic, scandals always eclipse happy endings. Whether watching Britney melting down on a gurney or philandering politicians caught without their pants, we can't avert our eyes from a smoldering implosion. Bruliam, of course, is no exception; wine mishaps, disasters, blunders and banana peel pratfalls trump a seamless fermentation any day. If you can't see the video posted below, please click here.
Note: We've been having a lot of trouble with YouTube and our audio. Right now the video is working fine, but it seems to be a fluid situation. If when you play the video and get no audio, please drop us a line to let us know.
And so it begins, in mid June 2008, when Mendocino Country suffered devastating forest fires that affected some 53,300 acres and caused $50 million in estimated damage (click here to read an article on the fires). Thick smoke blanketed the narrow, long throated valley and smothered the developing grapevines near veraison, when berries morphed from green to purple. Flanked by steep hills and a ridgeline peaking at 2000 feet above the valley's base, our grapes choked at the depths of a smoky basin; the polluted, stagnant air had nowhere to go, even as the fires were contained. Worried the resultant wine might taste like the soot, ash and smoke encasing our berries, we sadly learned that the scientific evidence proved us right. Australian studies (click here if you want to read one) that deliberately smoke developing grapes conclude that the smoke compounds from the air are thereafter measurable in the tested berry bunches. The smoky compounds penetrate both leaf components and wound sites along the vine. Finally meticulous work has demonstrated that smoke taint compounds applied to scalpel severed leaf flaps and decapitated shoots are ultimately absorbed in the fruit itself. And those compounds are in the grape skins, not the pulp, exacerbating the taint in red wines, where intensity of color and flavor is directly proportional to contact between grape skin and juice.
In one preliminary tasting of 2007 smoke tainted wines from north east Victoria, 7 Australian winemakers were asked to articulate the characteristics they most frequently noted. "Ash, drying, bitter, smoky, bacon, campfire (recently extinguished), and ashtray" were the winners, although "toasty/charcoal, dirty, smoked meat, and aniseed" appeared frequently, too. As you may recall, "campfire" was precisely the odor that induced my gut-wrenching reenactment of high school camping expeditions. The Aussies have the most data on this stuff, as they suffered devastating crop loss and vineyard damage in both 2003 and 2006/7 brushfires and are now the most proactive in fielding new scientific data on the subject.
To date, we already understand the basic biochemistry of smoke taint, since the burning embers of forest fires mirror the charred interior of toasted oak barrels- only amplified. When oak barrels are "toasted," chemical compounds from the resultant char leech into the wine as it ages, adding layers of complexity and flavor. From experience with oak barrels, we know guiacol and 4-methyl guiacol are the most important compounds (i.e. odiferous phenols) comprising the chemistry of smoked wood, although other secondary compounds are noted. Wood is 25% ligin, which is itself a long chain of phenol monomers, and as it burns, pyrolysis liberates these aromatics. The very act of combustion fragments those long monomer chains into smaller, free floating phenols, which we interpret as that distinctive ashy, smoky scent. The resultant reekiness varies with burn temperature and the material combusted. That's why Z, our resident Aussie winemaker, aptly noted Australia's burning eucalyptus trees liberated a more potent stench than our 2008, Anderson Valley, oak tree forest fires. Better a 2X4 plank than menthol, I suppose. But most frustratingly, there is little to do but wait.
As noted in the PressDemocrat, "We're making a guesstimate of 20 percent to 25 percent of the area that was burned really got toasted." And that's a lot of guiacol. Charcoal filtration and reverse osmosis may reduce the levels of smoke taint chemicals, but we're warned to proceed with caution. Testing is limited, and you risk stripping away the good stuff with the bad. As for us, we've got malo and some preliminary aging behind us. Our next step is to stay calm, withhold rash judgment, and taste what we've got.
Data sourced from "Understanding the sensitivity to timing and management options to mitigate the negative impacts of brush fire smoke on grape and wine quality- scoping study." Department of Primary Industries, Victoria, Australia 2007. MIS: 06958/ CMI: 101284/ Dr. Mark Krstic