SAN FRANCISCO — As wine grapes are poured into a container to be pressed, winery owner Robert Reyes supervises every step of the process.

As he took a sip, he said he "can tell it's going to be a good wine. It's got good Tannins. It's got good complexity." 

It may be a good wine, but there will not be as much to go around as years past. That is because, at Reyes Winery, their production was down this harvest by about 66%.

"You can see it had grapes on it and it actually died and we've seen a lot of that this year in the entire vineyard and so we will be replacing a lot this year," Reyes said as he pointed to a section of the vineyard that has dry grapes.

There are a lot of dry leaves on the vines, a result of hot weather and the fact that the vines were not as hydrated as in previous years.

"We are watering the same as we have every year, the difference being that humidity is going deeper and deeper in the ground and so the vines can't reach that deep at this point for the water," Reyes said.

Dr. Kaan Kurtural, a professor of viticulture and enology at UC Davis, said he's not surprised by what's happening at Reyes' vineyard.

"It's not that surprising to see those numbers," he said. 

Winegrowers must change the way they farm to maintain hydration and survive climate change, Kurtural said. For example, looking for alternative water sources, like storing and using wastewater, using compost and plant spacing.

"Trying to make use of everything we have is what it's going to take to keep these things going. It's a new reality now with climate change, summers are harsher so it's tough," he said.

As for Reyes, while his harvest was smaller, he doesn't expect that to affect the flavor or price of his wine. In fact, he's expanding and opening another wine tasting room and restaurant in Old Town Newhall.