Grape harvesting underway in Central California

FRESNO, Calif. (KFSN) -- Grape harvesting machines light up the night during this time of the year.

They slowly make their way through vineyards to shake off these Pinot Grigio grapes.

The nighttime harvest works better for keeping the machinery running smoothly.

"You're basically smashing the grapes off of there," says Fresno County Farm Bureau CEO Ryan Jacobsen. "There's sugar everywhere and so during the daytime, you're going to have that sugar crystalizing to the point where it's going to gum up the machinery and everything else. Secondarily, you don't want to start the fermentation process until you get to the winery."

Jacobsen is relieved to get his wine grapes off the vine.

Smoke from wildfires in the area wasn't enough to cause any concerns with this year's crop.

The hottest July on record though was tough on area produce.

"Specifically, what we saw with grapes was a delay in maturing, simply because plants are a lot like humans," Jacobsen said. "They slow down when it gets over that 102 mark and we saw a lot of days that were well above that."

Pinot Grigio, Zinfandel, Chardonnay and Merlot grapes are among the popular varieties that are grown here and enjoyed all over the world.

"When you talk California wine, the Valley is the majority of where it's grown," Jacobsen said. "Approximately 70% of California's wine is coming from the San Joaquin Valley."

When you look at Fresno County grapes, you'll find roughly half of the crop goes into making raisins.

The other half is split between wine grapes and table grapes.