Biking through Sonoma’s Russian River Valley, Chris and Elaine Hutchins of the chocolate company Cocoa Bon and a few friends taste some of the country's best Pinot Noir—and pedal hard enough to justify a decadent picnic lunch.

In California's Russian River valley, the fog that rolls in off the ocean most evenings makes for cool nights and mild days. Pinot Noir grapes love this kind of climate—and cyclists do too. That includes Chris and Elaine Hutchins, owners of the chocolate company Cocoa Bon, who are biking these winding Sonoma County roads on their annual fall wine country tour.

The Hutchinses once dreamed of buying a vineyard, only to realize “we were about $15 million short of the $15 million asking price,” Chris says. “But wine and chocolate are similar in a lot of ways,” Elaine adds. “You use the same language for both—tannins, antioxidants, mouthfeel.” Inspired by a tour of European chocolatiers, they launched Cocoa Bon six years ago in Los Gatos, an hour south of San Francisco. Their candies—such as almond toffee or chai-flavored caramel covered in Guittard chocolate—are now sold at Whole Foods Market and Dean & DeLuca, and placed on pillows as part of W Hotels’ turndown service. Last year, the company introduced the Cocoa Bon Chocolate Bar at Bay Area concert halls and theaters—“A bartender scoops the candies into cocktail glasses,” Chris explains—and in Santa Clara this summer it opened its first Cocoa Bon store, which sells items like serving platters and Tahitian vanilla sugar, as well as candies.

In past years, the Hutchinses have biked through Napa Valley, Carneros and parts of California’s central coast. Because the couple is fascinated by chocolate-and-wine pairings, these trips are part vacation, part R&D. On this long weekend in the Russian River Valley, the Hutchinses—along with a few friends, like Carrie Dove, a Bay Area caterer—start and finish in Healdsburg. There are plenty of wineries within five miles of town, but the Cocoa Bon crew is a bit more ambitious, plotting a four-hour course from Healdsburg to J. Rochioli to Gary Farrell to Russian Hill Estate, where they'll stop for a late picnic lunch.

Clad in fleeces and sweatshirts, the bikers head out in the early morning chill and follow the meandering, single-lane Westside Road, which is relatively flat yet challenging enough to get the blood flowing. When they arrive at J. Rochioli, winemaker Tom Rochioli appears in shorts and a T-shirt to greet them, his thick farmer's hands dirty from the morning's work. "I got all dressed up for you," he says with a smile.

Rochioli was founded in 1982 as a vineyard that sold its fruit to nearby boutique wineries like Williams Selyem and Davis Bynum. But in the past 20 years, Rochioli has become a top label in its own right, producing 9,000 cases a year. The winery has a mailing list (there's a six-year wait to get on it) for those who are determined to buy one of its $75 single-vineyard Pinots; otherwise Rochioli sells mainly to restaurants. But at the winery, the tasting room is pouring—and selling—Rochioli’s Estate Pinot, Chardonnay and Sauvignon Blanc.

The 2003 Estate Pinot, with a distinct black cherry aroma, has a velvety texture and nice acidity, but the finish is a bit short. Chris seems disappointed. “It’s got a nice nose,” he says with a shrug. “Still, maybe it needs to age for a while.” Tom doesn’t disagree. Rochioli Pinot tends to be at its best after it’s been cellared for three to five years. “Seven or even 10 wouldn't be uncommon,” Tom adds.

As the group pedals away from Rochioli, the sun is just starting to break through the morning fog. When the cyclists arrive at the stone pillars of the entrance to the 23-year-old Gary Farrell winery, the sun is blazing, and it looks like a quarter-mile climb straight uphill to reach the tasting room. Overhead, birds circle the cyclists, looking like buzzards waiting for someone to drop. At the top, Chris takes a breather, finishing off one of Carrie's homemade apricot energy bars studded with almonds and coconut.

"We don't get many bikers up here," the woman tending the tasting room says, pouring some chilled Sauvignon Blanc to lure everyone to the bar. As he sips the wine, which has a grassy, green apple nose, Chris asks about the birds he saw on the way up the hill. "Red-tailed hawks," she says. "They're looking for steelhead in the river."

While the group gathers around to taste the 2003 Russian River Valley Pinot, Elaine furrows her brow, trying to think of new chocolate flavors to pair with the wine. "Tahitian nut? Or maybe milk chocolate cherry," she says, proposing two possibilities for the Cocoa Bon lineup. Then she tries the 2003 Starr Ridge Vineyard Pinot, which has a cranberry aroma and a bit of toasted oak. "Now this is a more serious style, with more tannins," she says. "This would go great with our dark chocolate cherry."

When the cyclists finally reach Russian Hill Estate, an up-and-coming producer known for its smoky, earthy Pinots, they unload their backpacks onto a picnic table. Carrie pours a tangy tomato soup from a thermos, passing around the tarragon croutons in a separate container. Elaine takes out two kinds of sandwiches: curried chicken salad on biscuits flavored with the Indian spice mix garam masala and tender roasted pork with sauerkraut relish and pear chutney on baguettes. Everyone grabs double-chocolate biscotti and pumpkin bars topped with a walnut crumble—the perfect reward after a 15-mile ride.

As the group finishes lunch, Ellen Mack, Russian Hill’s cofounder, talks about how the area produces such great Pinot year after year. “It’s the hang time,” she says, explaining that the grapes like the long growing season: The fog prevents the fruit from getting too hot, so it ripens slowly.

From the back deck of the Spanish villa–style tasting room, there's a marvelous view of the valley and the oak tree–lined Russian River, with the Mayacamas Mountains to the east. The view only becomes more stunning later in the afternoon, when the long fingers of fog begin reaching back over the vineyards and the Hutchinses and their friends ride slowly back into town.

Cocoa Bon␁s new retail shop is in the Westfield Valley Fair Shopping Center at 2855 Stevens Creek Blvd. in Santa Clara, California; 408-261-2439.

Jeffrey M. O’Brien is a senior editor at Wired magazine.