Smoke taint is a catch-all term for damaged fruit due to smoke exposure. Smoke taint disproportionately impacts most red varieties, as the grapes experience fermentation on the skins. During the past ten days, Napa Valley has experienced a tremendous amount of smoke from fires inside and outside the county that continues to linger throughout the valley.
Our Howell Mountain Estate and Rutherford Dust Vineyards are heavily impacted. The effects of smoke can range from the muting of varietal character to the smell of liquid smoke used in cheap barbeque sauce. Walking the vineyard, we see a lot of ash on the leaves, the fruit, and the floor, which gave us enough data to decide not to pick fruit this season. There is no guarantee that the wines produced this vintage will be tainted, yet this is not a risk we are willing to take.
The smoke-tainting of grapes can happen either by ambient smoke or by falling ash. The volatile phenols (smells) absorb into grapes via the waxy cuticle on each berry. These volatile phenols can remain active or bind to the berry’s sugars and become glycosides. This means that the smell can no longer be detected. Once fermentation begins, however, these compounds can unbind via hydrolysis and smell volatile once again. The hydrolysis of these compounds is slow. It mostly happens during fermentation but can take place several years into bottle aging.
Some winemaking techniques can help mitigate the effects of smoke taint and include charcoal fining, reverse osmosis, spinning cone extraction, and flash détente. Some of these can be effective at a reduction, but they all have one thing in common: they do not meet our grape-to-bottle standards at Neal Family Vineyards.
You may recall that Napa experienced fires in 2017. We got lucky that year, as we were completely harvested before the fires came, which, thankfully, were late in the growing season.
Smoke taint is new to the farming and wine world in California. Not many professionals and specialists know all the answers at this time. We hope there will be a solution in the future to handle this new normal to our environment. The most challenging part is working all year tending the vines to have it taken away in one day. That said, we are farmers, we know the risks and love what we do, so we’ll be looking forward to 2021’s harvest. Our hearts go out to everyone impacted, from the vineyard workers to our neighbors and our community.