Some of California’s oldest and smallest wineries are among the 200 located in Sonoma, the Rhode Island–sized wine region nestled between Napa and the Pacific Ocean. Age translates to history. Size can mean an emphasis on quality over quantity.

Passalacqua Winery is a clear example of both. The Passalacqua family began making wine in the 1800s, and just a year ago, the fourth generation opened a new winery. Sonoma is noted for zinfandel and bordeaux varietals, so it’s not surprising that Passalacqua’s outstanding wines are its assertive, fruit-laden Dry Creek Cabernet Sauvignon 2002, and Old Vines Zinfandel 2002, from 70-year-old vines – intense, concentrated with an aroma of cassis and spice, including black pepper. In a region where many wineries produce 50,000 to 500,000 cases annually, Passalacqua produces just 4,000, sold at the winery and through www.passalacquawinery.com.

Dating to 1878, Everett Ridge Vineyards and Winery is the second oldest winery in Sonoma’s Dry Creek Valley. Today its owners produce 5,000 cases a year, among them Sauvignon Blanc 2004, fresh and lively with a bright grapefruit aroma; Russian River Valley Pinot Noir 2002, which captures the essence of this elusive grape; Dry Creek Valley Estate Zinfandel 2001, with forward fruit and a delightful berry quality; and Nuns Canyon Vineyard Syrah 2001, warm, vigorous, a terrific wine. They are sold at the winery or via www.everettridge.com.

Bella Vineyards and Wine Caves, which had its first vintage in 1999, offers one lovely wine after another. Its Big River Ranch Zinfandel 2002, from century-old vines, is exquisite, well-knit, full-bodied and deeply flavored. Belle Canyon “Estate” Zinfandel 2002 is rich and vibrant with hints of dark chocolate — a delicious wine. The winery produces 4,500 cases a year, sold on site and through www.bellawinery.com.

Edoardo Seghesio began his family’s wine business in 1895. Today, three generations work at Seghesio Family Vineyards (www.seghesio.com), a winery reborn a decade ago when it reinvented itself and reduced its output from 120,000 to 40,000 cases a year. Its most successful wines: zinfandel and Italian varietals.

Zinfandel is also the star at Mauritson Family Winery, whose history dates to the 1870s. Check out its stylish, supple Dry Creek Valley Zinfandel 2002 and powerful Rockpile Zinfandel 2003. Its current 5,000 cases are available at the winery and through www.mauritsonwines.com.