Sonoma Valley in California has for years been considered the poor cousin of its illustrious neighbor to the east, Napa Valley, producer of bigger, more intense, more expensive wines. Napa looks upon Sonoma as slightly countrified; Sonoma considers Napa a bit of a snob. They are separated by the Mayacamus Mountains, with Sonoma valley opening directly onto San Francisco Bay in the south. The water moderates the temperature year-round, warming in the winter and cooling in the summer. Breaks in the Sonoma Mountains to the west channel fog and cool ocean air into the northern part of the valley, creating more good conditions for grape growing.

Sonoma wines are top quality and represent the best values in California today. The most expensive usually fall far short of Napa's gilded peaks; less expensive Sonoma wines provide bargains even in this time of multiple cheap imports. Often those bargains come from wineries long established, with a daunting varietal choice and a reputation built over years and even generations. These wineries do not suffer from the debt burden of newer, flashier vineyards that price their cabernets and chardonnays according to loan schedules, rather than what they are worth on the current market.

One of the best Sonoma producers of good, consistent, well- priced wine is J. Pedroncelli Winery, founded in 1904 by a wholesale grocer and later run by his two sons, John and James. Grapes come from their own vineyards, and from growers in nearby Dry Creek and Alexander valleys. Pedroncelli produces two "vintage selection" premium wines, cabernet and zinfandel, that are not expensive, plus most everything else, including gewurztraminer and riesling. The wines are all clean and characteristic of the grapes involved, without too much woodiness or alcohol. According to John Pedronelli Jr., "We like to see people drink wine, not just taste it."

The winery, close by a Sonoma side road, appears small and compact, and the visitor will be surprised to learn that Pedroncelli produces 125,000 cases a year, which get wide distribution. Of the half-dozen wines I tasted there, I liked the '82 chardonnay, lightly oaked, with good fruit (less than $8); the '82 sauvignon blanc, smoky and very full ($6); and the '78 vintage selection zinfandel, with a big, briary nose and spiciness to spare, for the amazing price of $6.50. The '81 cabernet had good body and flavor, with a touch of bell pepper; the '80 was chewier, with better body and tannin for a couple of years laying down, at only $6.

At the other end of Sonoma valley is Glen Ellen, a much newer winery that proves newcomers can still make it. It is owned by the Benziger family that bought the moribund vineyard in 1980 and moved west en famille for some vinous pioneering. The result is nothing less than a bonanza. Glen Ellen wines are intensely fruity, quickly approachable, and incredibly cheap. The '82 cabernet ("proprietor's reserve") can be drunk now, and is a lively, berryish, delicious accompaniment for lighter meats, or for drinking all by itself, and costs less than $5. (It contains 15 percent zinfandel, allowable by law.)

The '83 chardonnay, with good fruit and a dry finish, needs a little time yet and sells for about the same price. Glen Ellen also makes an excellent, more expensive sauvignon blanc, a zinfandel and a quaffing white that is a blend of riesling, chenin blanc and French colombard. Both Sonoma and the general consumer should be thankful.