Smoke Left Unwanted Mark in Carmel

One winery uses Soberanes Fire as opportunity to run trials on mitigation strategies

by Andrew Adams
wine grape vineyard carmel valley soberanes fire
The U.S. Forest Service conducts restoration work in the aftermath of the Soberanes Fire in Monterey County, Calif. The fire burnt more than 130,000 acres and its smoke contaminated grapes in the nearby Carmel Valley.
San Rafael, Calif.—This summer, as the Soberanes Fire raged in Monterey County, winemakers and growers in the Carmel Valley watched as heavy smoke descended on their vineyards right around véraison.

Many of those affected hoped that their still-developing grapes would dodge any smoke contamination, but now that most wineries in the region have pressed off their 2016 reds, it appears that several may have had to deal with extensive smoke problems.

The fire was ignited July 22 from an illegal campfire and wasn’t declared fully contained until Oct. 28. The blaze burnt 132,127 acres, and the majority of that was in a rugged stretch of the Los Padres National Forest. The location of the fire was almost due west from the Carmel Valley, which is home to several wineries and vineyards. While the region’s topography and climate kept the smoke well north of the vineyards in southern Monterey County, including the Santa Lucia Highlands AVA, the smoke poured into the Carmel Valley.

Smoke like a ‘thick fog’
Matt Piagari, assistant winemaker for Joullian Vineyards & Winery in Carmel Valley, said the smoke appeared just as the winery’s estate vineyards reached véraison. “It was much like a thick fog you’d see in San Francisco,” Piagari recalled.

He said the winery’s head winemaker, Ridge Watson, knew from prior experience the smoke would likely be a problem so the winery contacted ETS in August for some initial analysis and found elevated guaiacol levels. “We knew pretty much then that we were going to have big problems,” he said.

Piagari worked with ETS to set up some Cabernet Sauvignon trials on smoke contamination mitigation in the hopes that the winery could learn some useful lessons it could share with other wineries facing similar problems in the future. While smoke taint is well known in the industry, it’s not something that everyone has dealt with firsthand. There’s not much in terms of research or trials for other winemakers to refer to when a wildfire springs up in their area.

With white varieties, Piagari said they pressed the grapes as quickly as possible, and that seems to have worked. Watson worked through the smoky harvests of 1999 and 2008 and produced high-quality Sauvignon Blancs in both years. He said the 2016 whites appear very similar.

Red varieties, however, were much more challenging. The strategy had been to quicken fermentation times and boost extraction with temperature and enzymatic treatments. Piagari said the winery pressed the last of its reds before the Thanksgiving holiday, and unfortunately the results have not been positive.

He said it appears smoke compounds can be extracted in as little as 3 to 4 hours, and so a fast fermentation may not be that effective. Membrane or cross-flow filtration remains an option, but Piagari said his understanding is those treatments may work in the short term but the smoke taint can return in about six months.

If Joullian’s trials accomplished anything, Piagari said it demonstrates trying to fix the problem in the cellar may not be the best strategy. He said fighting smoke taint in the vineyard may offer more potential to mitigate the problem.

Piagari said the winery sprayed the vines and clusters with a cream of tartar solution that did seem to be effective in getting the heaviest smoke deposits off the grapes. The excess moisture on the grapes can lead to other problems, but those are easy to deal with compared to smoke. “If you could find a way to rinse the leaves and grapes off earlier, before harvest, that might be something,” he said.

Making whites out of reds is another option. Piagari said the winery has some Muscat Hamburg grapes that were exposed to smoke, and while the skins tasted of “stale cigarette ash,” the juice came out clean, and the fermented white wine is rather pleasant and could be a varietal bottling or a blender.

Another option the winemaking team discussed was flash détente, but as the winery only makes about 8,000 cases per year with grapes from its 40 acres of estate vineyards, and the cost of shipping out small lots of up to 8 tons to flash operators just didn’t make sense.

Some grapes not worth harvesting

Jack Galante, winemaker and president of Galante Family Winery in Carmel Valley, closely monitored his crop during harvest in the hopes that the smoke would just add some interesting sensory characteristics. He told Wines & Vines in August that the smoke from the 2008 Basin Complex Fire created some pretty interesting wines, but this year the smoke proved too thick.

“We decided not to harvest our bigger reds this year,” he said in an email. “The guaiacol levels were off the charts. Sometimes a small amount of smoke taint can lead to some interesting flavors in wine, but with levels as high as they were for our area, we did not want to compromise the quality of our wines in any way.”

The USDA’s crop insurance program does provide coverage for losses in production and quality from smoke and fire damage. Quality losses need to be confirmed with prices reductions or lab tests if unsellable.

While several major fires in California caused widespread devastation in 2015, particularly in Lake County and the Sierra Nevada foothills, a USDA spokesman told Wines & Vines the agency paid just $100,000 in indemnities for fire loses and $75,000 in “heat” losses in June and July based on claims from Lake and Calaveras county.

Data for 2016 is still incomplete, but according to records available through the USDA’s website, there were two indemnities for Monterey County grape losses on more than 20 acres for nearly $70,000.

Posted on 11.29.2016 - 10:38:28 PST
Controlled studies have been replicated in Australia establishing that the smoke compounds are in the grapes rather than on them. Cleaning or protecting the skins seems unlikely to work. That isn't conclusive evidence that it won't work. But that effort could be wasted.

Also, it is incorrect that smoke taint will come back 6 months after treatment if done right. The study that showed that (again, Australian) nearly 10 years ago used a primitive technique and wine that had smoke taint compounds bound by sugar which were slowly released. Membrane methods have come a long way since then.

Links and citations to these studies, and a collection of best practices for handling smoke taint are available here: http://mavrikna.com/images/smoketaint2014.pdf
Bob Kreisher