I live in Napa city and was judging the Sydney International Top 100 Wine Competition when I received a call from my wife to tell me that she and my family were evacuating our home. Frightened for their safety, I flew home early to be with them. I had the honour of feeding and meeting the helicopter pilots that came from all over the world to the area. It was sometime after the smoke had settled that thoughts turned to how the fires might impact wine quality and supply.
The short answer is: Very little.
Ninety percent of Napa’s wine grapes had been fully harvested by the time the fires began. A significant proportion of the remaining fruit was abandoned on the vine and never harvested. The fires occurred well after veraison when grapes are photosynthesizing less, thus less susceptible to absorbing smoke. Strong winds decreased the risk of smoke taint developing in any of the remaining fruit. Smoke was not a problem in wineries, fermenting wines were protected by the released carbon dioxide and finished wines were sealed to protect them against any smoke that may enter the winery.
Most of the small percentage of wine effected by smoke taint will be sold on the bulk market, none will make it into the wines of the top producers.
Smoke taint is a minor issue for Napa’s 2017 vintage, and a complete non-issue for wines from the top estates. It occurs when free guaiacol and 4-methylguaiacol compounds develop smoky characters in wine. However, because smoke taint flavours develop during ferment and with barrel age, Napa Cabernet Sauvignon producers have plenty of time to detect these flavors during the typically eighteen months in barrel. Most of the small percentage of wine affected by smoke taint will be sold on the bulk market, none will make it into the wines of the top producers.
In fact, the fires are a minor player in Napa’s overall 2017 vintage story. The vineyard year started with beneficial winter rains, offsetting several years of increasingly intense drought. Then a series of heatwaves, including three days above 100°F (38°C) on the first weekend of September, followed by cool weather immediately afterward, resulted in an early harvest with good physiological balance.
Grape dehydration during the heatwaves provided relatively low yields of concentrated fruit. The biggest impact of the fires was that winery evacuations meant that reds were left on skins with no pump-over or plunging, which most winemakers actually considered a beneficial shift to their usual winemaking regime – resulting in nuanced wines with supple tannins.
As Napa Valley Vintners say in their vintage report, “Winemakers are optimistic about overall vintage quality but are predicting lower than average yields”. The 2017 vintage wines from the great estates such as Harlan, Screaming Eagle, Colgin and Opus One should be outstanding, but in shorter supply and thus likely more expensive.
Matt Deller is one of just 47 Masters of Wine in the US and an internationally respected wine judge, panelist and speaker