It’s harvest time in SLO County, and all the signs point to a ‘killer’ wine crop

What do you get when you combine a wet winter with cool summer temperatures? The chance for a “really good” wine grape crop, of course.

Wine harvest has begun in San Luis Obispo County.

Local growers say 2019 is on track to be a strong year — thanks to high rainfall during the winter and cooler than usual temperatures this summer that kept the grapes on the vines for longer.

“In the wine business we talk about growing degree days,” Bob Tillman, owner of Paso Robles winery Alta Colina, told The Tribune on Thursday. “We are 15 percent below where we would be in the past three years on this given day, which translates to about a two-week longer growing season.”

That lengthened vine time gives the grapes longer to develop and contributes to more aromatic flavors and higher sugar content, he said.

Tillman began harvesting his white wine grapes in the pre-dawn hours of Wednesday morning, roughly two weeks after he would normally begin gathering them, he said.

Leaves and stems are removed from bins of Marsanne grapes. Alta Colina in Paso Robles harvests wine grapes just before dawn in September. David Middlecamp

Alta Colina grows Rhône grapes on 31 acres of steep mountainside on the west side of Paso Robles. Normally the vines yield about 100 tons — or 3.2 tons per acre — a year, although Tillman said his initial estimates show the 2019 crop might be “a bit below average” in size.

But that isn’t an indicator of its quality, he said.

“As long as we get through September without any of these big heat spikes, I think we are going to have a hell of harvest,” Tillman said. “Hopefully we are going to make a killer wine.”

Warm temperatures, high yields

Another local winemaker keeping an eye on the weather is Fintan du Fresne, general manager of Chamisal Vineyards in San Luis Obispo.

“I hope it doesn’t get too hot over the next few days,” du Fresne told The Tribune on Thursday. “100 is a little warm.”

Chamisal Vineyards is about one-third of the way through harvesting its 95 acres of vines in Edna Valley. The winery will start harvesting from its Monterey County vineyard next week.

“This harvest crept up on us faster than we thought it would,” du Fresne said. “It was a pretty cool, wet spring, so the vines were kind of behind all season. But we’ve had nice consistently warm weather for the last few weeks, and because there is so much growth on the canopy, there are a lot of leaves to accumulate sugars.”

Maggie Tillman with Alta Colina in Paso Robles takes an cell phone photo at sunrise as the winery harvests wine grapes just before dawn in September. David Middlecamp

Du Fresne said so far crop yields have varied: Earlier blocks were below average, but other ones like their chardonnay grapes seem to be producing more than average.

“It wouldn’t surprise me if it averages out to a little above average,” he said.

Christopher Taranto, communications director for the Paso Robles Wine Country Alliance, said the crop yields across the region seem to be higher than previous years, especially considering the recent drought.

“There is definitely more fruit out there,” Taranto told The Tribune on Thursday. “This last rain we had — the 2018-19 rain — was, they are saying, substantial enough that it is giving these vines a lot of that moisture.”

That’s good news for San Luis Obispo County if that holds true, potentially pointing to another record-breaking year for the lucrative local crop.

Wine grapes were the county’s top crop for the third year in a row in 2018, with a value of about $276 million, according to the San Luis Obispo County Department of Agriculture.


Alex Frost, assistant winemaker at Sextant, said the San Luis Obispo winery is about 5% to 10% of the way through its harvest.

Sextant expects to produce about 450 tons of grapes — on the lower end of the winery’s average, he said, but still well within the norm.

“We definitely saw the vines pushing out a lot of fruit thanks to the rains we had this year, but we try to get in front of them to trim them off and have them not work too hard on the fruit,” Frost said.

Those rains also meant the winery didn’t have to water the vines until well into the summer months, Frost said.

“Didn’t have to add a drop of water until about June,” he said. “The vines were happy and had plenty of moisture.”

From there, Sextant jumped into harvesting some of its earlier-ripening grapes in mid August, and is now partway through harvesting other white wine grapes in Paso Robles and Edna Valley.

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Alta Colina in Paso Robles harvests wine grapes just before dawn in September. The last row of Marsanne grapes for the day are placed in bins. David Middlecamp

Next week, harvesters will start focusing on the red wine grapes, Frost said.

“We’re really happy about the way things are shaping up right now,” he said. “A lot of things are gonna ripen up at the same time — once the reds start coming on line, they’re all going to want to come off at the same time.”

“Always kind of turns into a balancing act,” Frost added.

Late harvest woes

Taranto said the cooler summer temperatures have kept the grapes on the vines for longer for a lot of local growers, but he anticipates heat spikes in the coming days could “jumpstart a few people.”

Overall though, he said most are preparing for a longer-than-usual harvest.

“At this point in time it’s mother nature,” Taranto said. “It’s going to take a while for things to get ripe. We’ll probably be well into November before harvest ends.”

Trouble could arise, Taranto said, if the weather turns cold and wet before the grapes can be harvested, and mildew sets in.

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Alta Colina in Paso Robles harvests wine grapes just before dawn in September. David Middlecamp

“Nobody wants that,” he said. “We need the Paso warmth that everyone knows us for to get us to the end.”

At Chamisal, du Fresne said as long as the weather holds, he’s optimistic that this year’s crop is a strong one.

“Time will tell,” he said. “The early stuff we are seeing is really good. There’s no reason why 2019 shouldn’t be a really, really good year.”

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Kaytlyn Leslie writes about business and development for The San Luis Obispo Tribune. Hailing from Nipomo, she also covers city governments and happenings in the South County region, including Arroyo Grande, Pismo Beach and Grover Beach. She joined The Tribune in 2013 after graduating from Cal Poly with her journalism degree.