Grape growers in Mendocino County, one of California’s most northerly wine regions, are both proud and embarrassed to state the following fact:

More than 80 percent of the fruit grown in their area leaves the county and is made into wine elsewhere. For the most part, this is stealth wine.

A lot of Mendocino County wine is used as the heart (and soul) of blends that say the wine is from “California,” a 58-county monstrosity. Such a designation tells you nothing about the pedigree of the wine.

Thus is Mendocino’s legacy mute. But if you were to look ultra-closely and taste all of the wines that say “Mendocino” on their labels, you’d see a key reason this fruit is so widely prized. Not only is it superb fruit, but also it is generally priced affordably, allowing the California-designated blends to taste darned good without the price reaching the stratosphere.

But which “California” wines contain Mendocino fruit, and which are blends that lean more heavily on hotter-climate grapes?

Rarely can you tell. You might assume that a $3 wine would be made entirely from hot-climate fruit, and that a $10 wine would be made from some hot-climate fruit and some from cooler regions such as Mendocino, Monterey and other areas.

But that’s not always the case. Few wineries tell you where the fruit came from for their cheaper wines, and even if you were to find out for a single wine, things could change by the next vintage.

And asking a Mendocino County-ite rarely helps, because often growers are sworn to secrecy.

Just why that is was made clear to me the other day while chatting with a Mendo grower. He told me he had sold some good cabernet sauvignon to a Napa Valley winery, “and they’re using it in their $80 cabernet,” he said.

Wineries in California can still use an appellation on their labels as long as 85 percent of the wine is from that region. Thus 15 percent can be from somewhere else, and often that “somewhere else” is a place as high-caliber as Mendocino.

I asked the grower how much he sold those grapes for. “A lot less than the $6,000 (the Napa winery owner) paid for his Napa cabernet,” he said ruefully.

Unfortunately, even though many Mendocino County-produced wines, under homegrown labels, are of excellent quality and reasonable price, the vast majority of the names of these properties are unknown.

Part of this is due to the rapid growth in the number of wineries here, leading to such new names as Girasole, Bliss, Naughty Boy, LeVin, Raye’s Hill, Albertina, Bloom, Barra, Standish, Three Families, Breggo, McFadden and McNab Ridge.

The last brand, founded by pioneer winemaker John Parducci and his grandson, Rich, has made a superb 2006 French Colombard ($12) that exhibits the bright, spicy pineapple and melon fruit of the variety. Lovers of fresh, fruity white wines will love this wine.

The best wines in Mendocino County are the entire lineup from small Navarro Vineyards — available mainly at restaurants and at the winery: 800-537-9463.

Other widely distributed wines from Mendocino that are exemplary are from Fetzer (including the Bonterra line from organically grown fruit); Greenwood Ridge (including a spectacular 2006 rose); all the wines made by Greg Graziano, notably in his Monte Volpe label; Handley Cellars, notably a great sparkling rosé); Husch; Eaglepoint Ranch (including a delightful grenache); and the wines of Parducci, as well as other Mendocino Wine Co. brands.

Wine of the Week: 2006 Husch Chenin Blanc, Mendocino County ($11) — Fresh and brightly aromatic of melons and tropical fruit. Soft and slightly sweet on the palate, but with good acidity. It would be a superb accompaniment to spicy Thai food. An annual winner.

Dan Berger resides in Sonoma County. Berger publishes a weekly newsletter on wine and can be reached at danberger@VintageExperiences.com.