The story of the vine is a story of human migration. From Gaul to Botany Bay, Vitis vinifera has been planted wherever the shock troops of Western civilization landed. Missionaries brought the good grape along with their good word, followed by ordinary people seeking opportunity. California's would-be "state grape" (if not for our Austrian immigrant governor's veto), Zinfandel, arrived anonymously from some European backwater, its name bowdlerized as if by an indifferent ellis island agent and became an iconic equal of the "noble" grapes. Meanwhile, Italians who labored in the vineyards in the 1800s founded their own. even now, local families are realizing the dream, becoming among the first Mexican-American winery owners since General Mariano Vallejo. What's that, it's Cinco de Mayo this week? What a coincidence!

It seems like every new winery can disinter some Italian great-grandpa to provide an illusion of hands-in-the-dirt continuity. Robledo Family Winery is the real deal. Reynaldo Robledo Sr. emigrated from Michoacan in 1968 and worked his way up from field hand, eventually founding a vineyard-management company and recently building the winery. A small army of his children run all aspects of the family business, which uses their heritage in a way that's both proud and savvy.

Yet the empire-building Robledos did not go over the top with their tasting room. Entry is via a plain service door. The middle of the barrel room, where Luis Robledo or his twin brother welcome visitors, is decorated with family portraits and Mexican art. The background music: ranchero, of course. Because of the stool seating, there's no elbow-war claustrophobia at the bar. a big tour group that arrived before me was safely seated at a table.

The first taste offered is the 2005 Sauvignon Blanc ($16), which is such a delicious standout of ripe melon fruit, finishing sweet and round, that it overshadowed the pleasant and balanced but more neutral-tasting Pinot Blanc and Pinot Grigio. The 2003 Pinot Noir ($32) is made in a tight, fresh style, pomegranate fruit without the tartness. The 2003 Merlot ($29) shows 18 months in American oak, but the wood is saturated in dense, chewy fruit and an intoxicating brandy cordial aroma, while the equally structured 2002 Reserve ($36) is less interesting. The distinctive 2003 Chardonnay ($30) may be redolent of nacho cheese, but it could have been power of suggestion. The 2004 "Los Braceros" Red Blend ($30) is a robust brew of blackberry and parching tannins, demanding the heartiest barbecue available. What about zesty Zinfandel, notable in its absence, typically paired with spicy cuisine? Luis says the Zin's coming. Mañana.

Robledo Family Winery, 21901 Bonness Road, Sonoma. Tasting room is open daily; Monday-Saturday, 10am to 5pm; Sunday, 11am to 4pm. Tasting fee, $5-$10. on Saturday, May 5, the winery hosts a Cinco de Mayo celebration from noon to 3pm. $40-$55; RSVP required. 707.939.6903. a winemakers diner at Noona's Bar and Grill follows that night at 7pm. 2233 Larkspur Landing Circle, Larkspur. $85; reservations necessary. 415.464.8711.

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