Winemaking: Warm weather creates challenges for Sonoma Valley harvest

SONOMA COUNTY, Calif. (KGO) — In the North Bay, extreme heat is keeping winemakers in the wine region on their toes. The grape harvest is in full swing and the heat is adding an extra layer of concern about the harvest.

“It’s a very difficult time, you have to stay focused every day, all day long,” Steve Ledson said.

The Ledson family has been growing grapes in Sonoma Valley since 1860. The work is never easy or predictable.

“This week we focused on our Chardonnay and Sauvignon Blanc,” Ledson said.

The grapes are poured into a giant press. The juice is collected underneath.

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During the night, workers at the Ledson vineyard picked about seven tons of grapes.

This week, timing is everything.

Extreme heat spikes accelerate harvests.

Ledson says vines are a lot like the human body.

“When it’s hot, the system shuts down, so if the temperature goes above 32 degrees, it wants to go to sleep,” Ledson said.

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Justin Schuchardt, associate winemaker, says the problem is dehydration and over-ripening.

“The heat is a challenge. We want to get the fruit off the vine before the heat can damage it,” Schuchardt said.

Knowing how to anticipate weather conditions and when to irrigate is essential. In the vineyard, Ledson was monitoring his old Zinfandel grapes.

“It’s supposed to be cool now, which is a good thing. It slows down the ripening process,” Ledson said.

The Sonoma Valley Vintners and Growers Alliance says the growing season still presents challenges.

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“Mother Nature is a force to be dealt with, so what winemakers and producers are trying to do is work with Mother Nature, she determines when things happen,” said Alliance executive director Robyn Sebastiani.

Back at the crushing plant, Ledson sampled the crop.

“It’s a delicious wine, it’s going to be a great year. Enjoy this wine,” Ledson said.

The harvest is expected to last until October.