The size of the North Coast grape crop jumped 25 percent last year, an unexpectedly large increase that will likely drive down wine prices for consumers while generating a $1 billion bounty for the region's growers.

Growers in Sonoma, Napa, Lake and Mendocino counties hauled in more than 444,000 tons of their prized wine grapes in 2009, reversing a three-year decline, according to the California Department of Food and Agriculture's preliminary grape crush report issued Wednesday.

The rebound helped push the state's total grape crop to its second largest ever — 3.69 million tons, a 21 percent increase over 2008 and just shy of the record 2005 crush of 3.76 million tons.

"We knew it was big, but we did not think it was this big," said John Ciatti, partner in the Ciatti Company, a San Rafael wine and grape brokerage. "This crop will put additional pressure on the already struggling premium segment of the wine business."

The large crop and high quality of the vintage will make it tougher for North Coast growers to command high prices for their grapes and will continue to pressure wineries to slash prices.

That means higher-quality wines should be available at lower prices for the foreseeable future, said Brian Clements, a partner in Turrentine Brokerage, a Novato wine and grape broker.

"I think in general the consumer wins big this year," Clements said.

Statewide the size of the crop just missed a record, but because the average price rose to $608 a ton, the value soared to an all-time high of $2.2 billion.

The value of North Coast's grape crop increased 23 percent, to $1.05 billion, from $859 million the prior year, according to the report. The crop topped $1 billion for the first time in 2005, and remained there for the next two years before last year's anemic harvest dragged it back down.

In Sonoma County, local growers brought in nearly 212,000 tons of fruit, a 25 percent increase in volume and a 22 percent increase in value at $456 million, according to the report.

Chardonnay led the charge, with its 73,000 tons representing a 36 percent increase over 2008. Chardonnay prices fell 2.4 percent to $1,959 a ton.

Cabernet sauvignon also came on strong, with a 28 percent increase to 41,000 tons. Prices fell 2.9 percent to $2,183 a ton.

Despite a 3.9 percent dip, pinot noir in Sonoma County continued to command the county's highest average prices, at $3,033 per ton.

The county's average price per ton dipped 2.8 percent, to $2,155 from $2,216 the prior year, a county record.

The relatively slight decrease in price combined with the large increase in volume means growers reaped better returns last year despite the dramatic drop in prices for unsold grapes at the end of last season.

"I think that's some good news for growers," said Nick Frey, president of the Sonoma County Winegrape Commission. "Last year was a rough year, and those numbers say that in the end there was some progress."

The vast majority of growers have long-term contracts with wineries, protecting them from the precipitous decline in prices that occurred when cash-strapped wineries didn't go shopping for extra grapes on the spot market late in the season.

Wineries will likely continue to be conservative in their grape buying in 2010, and that may mean less leverage for growers, Frey said.

"I would say that it will be a tough year for negotiating contracts," Frey said.

Napa County growers again commanded the highest grape prices in the nation, at $3,267 per ton. It harvested 141,620 tons, for a value of $462 million, just edging out Sonoma.

Mendocino County grapes fetched an average of $1,315 per ton. The county harvested 59,335 tons of grapes for a value of $78 million.

Lake County's 31,541 tons went for $1,229 per ton, or a crop value of $39 million.

The upside of lower grape prices, however, is that large U.S. wineries might no longer be tempted to import so much bulk wine, said Ciatti's Glenn Proctor. A flood of low-priced wine from abroad aimed at slaking consumers' thirst for cheaper wines hurt demand for California grapes last year, Proctor said.

"Now there's potentially enough volume at the (lower) prices that they are going to stay in California," Proctor said.