Warming weather welcome news in vineyards

By starting after daybreak and avoiding having workers wear headlamps while picking grapes, today will almost certainly be an improvement in what has been a wet and wild week for Sonoma County grape growers.

An unseasonably heavy rainfall last week sent workers scurrying to the fields to pull fruit from the vines before they absorb too much water and dilute their flavor.

That meant crews wearing headlamps, walking the rows at 4 a.m. Monday under the watchful eye of Wine Creek Vineyard owner Mike Rowan, who grows fruit for Clos du Bois, among other wineries.

They beat the return of the rain on Monday, but not the cold and Rowan called it quits around 7:30 a.m.

“Some wineries want the highest sugar they can get and if there is any water on the grapes there is a slight dilution factor,” Rowan said.

The grapes that crews were able to pull from the vines on Rowan’s Dry Creek Valley property were largely devoid of excess moisture and telltale signs of bunch rot, technically known as botrytis rot, and also the green mold on red grapes that has farmers worried what will happen to their remaining grapes.

“You just kind of watch — are you getting bunch rot or green mold that can take over once it gets started?” said Nick Frey, president of the Sonoma County Winegrape Commission. “The bad cluster will either get thrown on the ground or people will be instructed not to pick them.”

For growers with fruit still on the vine, the weather is expected to improve this week.

After nearly a half-inch of rain fell in downtown Santa Rosa Monday, only spotty, if any, showers are expected Tuesday. Temperatures are expected to hit a high of 70 today, gradually increasing to between 75 and 80 degrees Friday.

“It’ll be dry, slightly warmer each day,” said U.S. Weather Service meteorologist Steve Anderson.

Already more than 3 inches of rain have fallen in Santa Rosa, compared to the seasonal average of 1.39 inches. A lot of that precipitation fell in last week’s storm, which dropped about 2.7 inches in Santa Rosa.

In a tour of some of Sonoma County’s grape growing regions, Frey said he was happily surprised with the lack of damage from the heavy rains.

“The grapes I saw were in good condition. They were obviously nice and clean and bright,” he said.

Merlot and cabernet grapes are the main fruits being harvested now, Frey said, with small pockets of other varietals still out.

Rowan was dealing primarily with cabernet franc and cabernet sauvignon grapes in what he expects to be his final two days of picking.

The wet weather over the past week has pressed grapegrowers into action — cutting leaves away from the fruit to allow air and what little sun there has been to dry the grapes out. Many growers have enlarged their hand-picking crews because the ground is too saturated to run machinery down the rows.

That’s an added expense, Rowan said. “There is tremendous cost savings to be able to use a machine where you can,” he said.