Napa set for great harvest or rot — depending on the weather

Weather in Napa has meant as much as 20% of grapes could be harvested in November but there is concern that cool conditions and frost could cause issues, according to one producer.

A stormy winter followed by cool spring and summer has resulted in the longer growing season, John Anthony Truchard of John Anthony Family of Wines, told Fox News, with the fruit potentially susceptible to fermenting on the vine.

In the previous few years hot weather has resulted in a shorter growing season, with grapes collected by the end of October, but the weather across the past twelve months has pushed the growing season into November, where normally there would only be around 5% left on the vines.

Veraison – where grapes turn colour, in this case from green to purple – happened around two to four weeks later than usual this year, with minimal heat waves in this cycle.

He said:”More typical in Napa Valley is a longer growing season where we may still have 5-10% to harvest in November. This year, due to a wet winter and spring earlier this year followed by a cooler summer, that number could be as much as 15-20% still to harvest in November.”

“With the slight heat spikes we’ve had late in the 2023 growing season, it looks to be not only a heavy-yield vintage with plenty of the ripeness development we’ve been looking for, but also a year of excellent quality. An extended hang time allows the grapes maximum opportunity to develop flavor and intensity.”

Sander Scheer, John Anthony’s Director of Vineyard Operations, said on a blog post dubbed “The Long Game” on the company’s website that a long, slow ripening curve “typically provides excellent physiological ripeness in the fruit, with the flavours, phenolics, and acidity all coming together nicely” and said “the message from our winemaking team is that they’re excited about the flavors they’re tasting. The quality is absolutely there if you are patient.”

Truchard added the two recent quick rains so far were just a “nuisance, not a problem” but such weather can trigger rot on the vine and too much rain can cause it to split as well as diluting sugar content. If temperatures fall to freezing levels as well, as is predicted they could, it could cause grapes to be picked before they are ripe.

He said:”This is something Napa doesn’t have a lot of experience with. Should this happen, the best solution is to pick immediately. The frost would break the cell walls of the grapes down and if you were to let the grapes stay in the field too long after the frost, the berries would start fermenting on the vine, which isn’t ideal.”

But he also said that he hopes the combination of conditions could still leave to an “exceptional wine” and vintage for 2023.

The producer’s website blog on the weather said: “The longer the harvest season goes, the higher the chances of disruption by stormy weather. This is where John’s hard-earned farming expertise comes into play—no matter what Mother Nature brings; our team has the know-how to adapt and manuevre to the best possible outcome.

“For now, all things are pointing to a banner vintage for our Cabernet Sauvignons and other wines—a fitting reward for the patience and effort that got us here.”