2010 Sonoma Vintage

The season unfolded in order. Record-breaking low temperatures in spring led to a late budbreak. May brought 20 days of rain, double the historic average, and with many vineyards in bloom that meant a stunted crop and clusters that matured unevenly. Summer stayed cool, with plenty of fog and cloud cover, and mildew and botrytis were a threat all season. Many growers dropped crop and pulled leaves to open canopies for sun and airflow. In late August the heat arrived, with temperatures above 100 degrees F for days on end and records broken around Northern California. The cool summer delayed the start of harvest by two to three weeks, with most vineyards expected to pick in earnest from mid-September through October. A major storm dumped 4 inches of rain a week before Halloween. Sonoma and Marin tonnage came in 9.7% below 2009, and yields were below average.

• Spring: record cold, a late budbreak, and 20 days of rain in May during bloom
• Summer: cool and foggy, with David Ramey calling it the second coldest July in 50 years; mildew and botrytis pressure all season
• Late August: days above 100 degrees F sunburned fruit, and even bunches covered by leaves withered
• Late October: a storm dropped 4 inches of rain a week before Halloween

Much of the damage came from the first late-August blast, though other heat waves followed during harvest. Bob Cabral of Williams Selyem told Wine Spectator, "The extreme heat literally cooked the clusters." Zinfandel took the hardest hit, particularly old vineyards that lacked irrigation, and nowhere more than in the Russian River Valley. "The destruction on old-vine Zinfandel was unprecedented," Mike Officer of Carlisle told Wine Spectator. Sonoma and Marin Zinfandel tonnage was down 30.5% from 2009.

• Zinfandel: hardest hit, especially old vineyards without irrigation in the Russian River Valley
• Papera, which sells grapes to Carlisle, Williams Selyem and Novy: a total loss
• Other vineyards lost 40 or 50 percent of the crop
• The heat turned perhaps 10 percent of the county's crop into raisins

Yields were down on all varieties, but winemakers told Wine Spectator quality was surprisingly good where wineries were aggressive about dropping damaged fruit in the vineyard or sorting it out at the winery. Whites such as Chardonnay and Sauvignon Blanc, largely harvested before the October rains, fared best. Reds such as Cabernet Sauvignon and Merlot were more variable, depending on whether they ripened before the storm. David Ramey described the newly fermented wines as "a little lower alcohol levels, but not meager" with "very nice texture and balance."

• Whites (Chardonnay, Sauvignon Blanc): largely harvested before the October rains
• Reds (Cabernet Sauvignon, Merlot): more variable, depending on ripening before the storm
• Sorting was the dividing line: quality held where damaged fruit was dropped or sorted out
• Mark Lyon of Sebastiani called it "the most challenging and difficult harvest that I've encountered in a long, long time"

The weather hit during a weak market. In late August about 20 percent of Sonoma County's grapes were still unsold with only a few weeks to go, with a forecast of about 190,000 tons, about 5 percent below normal. Average prices in Sonoma and Marin were down 8.0% to $2,011 a ton, with gross grape revenues of $386,073,791, down 17% from 2009. Pinot Noir was again the leading red variety for revenue, ahead of Cabernet Sauvignon by $5.1 million.

• About 20 percent of the county's grapes were unsold in late August
• Average price in Sonoma and Marin: $2,011 a ton, down 8.0%
• Gross grape revenues: $386,073,791, down 17% from 2009
• Chardonnay led the six leading varieties at 66,157 tons, down 9.5%