2010 a vintage crop?

Wine-grape growers in San Luis Obispo County have had to deal with below-average temperatures this past summer, record-breaking heat several weeks ago, and most recently, rain during picking.

Yet, the unusual weather pattern hasn’t caused much of a slowdown to this year’s harvest of the county’s top crop.

On the east side of Paso Robles, for example, many of the vineyards along Union Road finished picking fruit last week, well within the time period grapes are normally harvested in that area.

Winemakers and grape growers are optimistic about this year’s crop. They say the grapes are high quality and yields are already topping those of 2009.

“Our crop is 20 percent more than last year, and overall the quality is very, very good,” said Tom Hinkle, who owns Rio Seco Vineyard and Winery in Paso Robles.

Wine-grape values last year were $166 million, or 27 percent of the value of the county’s farm production, according to the county Agriculture Department.

So far, prices this year are ranging from $500 to $2,500 a ton — about the same as last year, grower Richard Sauret said. But prices could drop if the market becomes oversaturated, he added.

The recent wet weather caused a few days’ delay in picking for some growers. Those with fruit still on the vine were concerned about bunch rot. “In 15 years of doing this, I’ve never had to deal with that,” Hinkle said. Bunch rot is of specific concern to zinfandel growers because the variety is thin-skinned. Too much moisture can cause the skin to split, and the fruit will rot.

Steve Carter, vineyard manager for J. Lohr Vineyards in Paso Robles, is excited to see what this year’s crop produces. “The mild summer has been good for the grapes. Overall, we had a cool year, so the color, flavor and balance all look good,’’ he said.

“The cooler temperatures increase the acidity in some varieties. That’s an advantage. Excessive heat can burn up the fruit.’’

A small amount of rain isn’t a setback, he added, noting that “as long as another storm doesn’t pass through, we should finish up harvest by the end of the month.”

Sauret finished harvesting his grapes from his vineyard on Drake Road in Paso Robles on Sept. 25 — before the recent heat wave and rain.

“This year, I have perfect drop, perfect numbers and perfect flavor. It might be the best since 1952,” he said.

As president of the Independent Grape Growers of the Paso Robles Area, Sauret hears how things are going at other vineyards throughout the county. “Those who have already picked their grapes are in good shape,” he said.

But he noted that growers with any fruit still to be harvested run the risk of further problems with weather. “I think about 30 percent of grapes are still hanging, and that’s not a good thing.”

In the South County, growers were glad to get the recent rain. John Alban, owner of Alban Vineyards in Arroyo Grande, said the heat wave “overly accelerated” the grapes, and the rain that followed helped slow that down. “Sometimes a little rain perks the vines up.”

Rainwater also recharges underground aquifers and flushes salt out of the root zone. When salt levels get high enough in the vine, the leaves start to display browning, or “leaf burn.”

Not wanting to make predictions about this year’s harvest, Alban chose his words carefully. “I am eternally optimistic, but I think it’s just too early to call. But, at this point, I would say we’re halfway down the long stretch of a horse race. If more rain comes, all of that could change.”

If the weather cooperates, harvesting is expected to end by early November.

There might be some challenges ahead, however. John Lindsey, a forecaster in San Luis Obispo, said in his outlook issued Thursday that there is a possibility of light sprinkles developing Sunday night across the county.

Another chance for rain might occur Oct. 23, Lindsey said. Computer models are starting to indicate formation of a storm system off the coast late next week.

The grapes being picked now will be ready to be bottled in about a year, depending on the variety. The aging process for white wines is generally three to 10 months, while for red wines it’s anywhere from six months to three years.