It comes after the San Francisco Chronicle reported that high temperatures across the Labor Day holiday weekend in Napa were shrivelling grapes before vineyards had had a chance to harvest them.
According to the US paper, temperatures at St Helena in the north of the region soared to more than 110 degree for three days in a row, with winey Crocker & Starr Wines estimating that some blocks had lost up to half of their crop as a result of water evaporating from the grape and shrivelling to raisins, while Hirsch Vineyards in Cazadero said yields could be down by 10% due to the excessive heat. It also expected to downgrade some of it wine for bulk, the San Francisco Chronicle reported.
However speaking to db today, Justin Knock MW, director of the Californian Wine Institute UK said it was too early to say what the effect of the unseasonably warm weather might have on yield expectations.
‘Too soon to tell’
“It’s going to be too early to say what the final impact on yields is going to be, as the impacts will be on a vineyard by vineyard basis,” he told db.
He pointed out that the harvest was still ongoing, with some vineyards already picked, making them unaffected. Those most badly affected were likely to be vineyards on the cusp of picking as grapes could overshoot quickly, leaving no opportunity for the vines to recover.
Knock argued that Pinot Noir and Chardonnay could be more affected than Cabernet, in part due to the focus of Napa’s Cabernet producers on quality and selection of the grapes, and Zinfandel, which can carry more richness.
“Ironically it could be the coolest sites most overtly affected – warmer sites may well have already harvested. Both the latter varieties are further away from harvest, particularly those in cooler sites, and have a little more time to recover,” he said.
Bryan Parker, winemaker at Federalist told db that although the vineyard was hit by temperatures of 113-114 degrees over the Labor Day weekend, overall the vines made it through the heat and the quality of the grapes was looking “excellent”.
“Because of the heat, we brought in one old vine dry farmed Zinfandel from Napa. We do see some raisining from this heat spike especially on Zinfandel but overall the vineyards made it through well. The quality looks excellent right now”, he told db.
He added that of the vineyards already picked, yields had been average or slightly lower, but Federalists was expecting Dry Creek to yield a “decent” crop of Merlot, Syrah and Cabernet Sauvignon, while the Mendocino Merlot, Cabernet Sauvignon, and Malbec were still several weeks away from picking.