As prices for top-rated chardonnay wines have disappeared into the dim haze beyond $10, the search for alternative white wines of quality has become more and more frantic. Two other white wine grapes, the riesling and the sauvignon blanc, are most often nominated as making wines of classic quality in a league with the chardonnay.

The riesling, of course, produces many of the great wines of Germany and of Alsace as well. In California it has gained popularity as the Johannisberg or white riesling. Sauvignon blanc made its mark in France, in the Bordeaux and Loire regions. It is the grape of most dry white Graves wines and such admired Loire appellations as Sancerre. Dry, crisp, flinty are words often envoked to describe it.

Not so long ago, much of the sauvignon blanc coming from California was off-dry or even sweet. That has changed. Now most sauvignon blanc is dry and plantings are on the increase. Much of the credit for making the wine popular with consumers is given to Robert Mondavi, who in 1971 coined the term "fume blanc." While "fume" (which means "smoky" in French) invokes thoughts of the tangy wines of the Loire, Mondavi's wine is generous and soft, suggesting neither the Loire nor Graves. Another factor, perhaps only psychological, is the use of Burgundy-shaped bottles for many of these wines. It's the same bottle used for chardonnay.

While it is no more a "substitute" for chardonnay than zinfandel is a substitute for cabernet, it is a welcome addition to a dinner party and can be served with a wide range of dishes, say from raw shellfish to poultry with cream sauce. Retail prices vary from $3 to $8.

Gallo is the largest single producer of sauvignon blanc an its wine has gained considerable credibility with wine buffs. Increasingly, however, small wineries in such prime growing areas as Napa and Sonoma have introduced highly personalized versions of the wine. "A lot of people think it's a neutral wine, like chenin blanc," said Richard Arrowood of Chateau St. Jean, "but it's not. It has as much character as gewurztraminer and the potential for detecting differences from one to another to me is greater than any other variety."

That certainly was the case in a recent tasting conducted by The Washington Post. Opinions and emotions ran high both for and against several of a dozen California sauvignon blancs. Once the dust had settled, the tasters agreed they were impressed with the wines as a group. More impressed, in fact, than the ratings indicated.

One reason for this disparity is what Arrowood calls the "agressive character" of the wine. To put it bluntly, sauvignon blanc has a strong smell. Call it "grassy" or "weedy" and wine scientists such as Arrowood wince."'Grassy' implies bacterial spoilage," he said, suggesting that "spicy" or "peppery" would be a fairer term. Frankly, that's too nice. Maybe a compromise word would be "herbaceous." In any event, some of the wines never compensated for that first sniff.

Obviously in the starkness of a wine tasting this characteristic is emphasized. It will be less obvious when the wine is served in a social setting with food and can be mitigated by time in the glass and even the age of the wine. Arrowood said the Chateau St. Jean sauvignon or fume blancs with the strongest personalities are now given an extra six months of bottle age before release.

In its favor are the character and body of the wine. Unlike some white wines from California, it can possess enough acid to offset a relatively high alcohol content. Well-made sauvignon blancs are not flabby. It also can have fascinating hews of color, ranging from pale to greenish gold. Some find hints of green olives in the taste.

Few would question a sharp distinction between the taste of French and American sauvignon blancs. The poor showing of the French wine included in The Post's tasting should be regarded less as a comment on the wine than a dramatic example of differences in style. For most, the Sancerre just didn't taste right in the company it was keeping. (The tassters were not told a "ringer" had been included.) Putting aside the characterless California sauvignon blancs that have been toned down by blending with other wines from grapes such as chenin blanc, columbard or Thompson seedless, it is obvious that it will take more time before a definitive domestic style (or several) emerges.

The tasting reported here was conducted "blind," meaning the tasters did not know the identities of the wines until scoring and appraisals were completed. A grade scale of 10 to 20 points was used, by which a "perfect" wine would have received 20. Comments represent a summary of tasters opinions, with some obvious contradictions about specific wines reflecting minority views. Price represents the shelf prices at Continental Liquors, the store where the wines were purchased. They may vary at other shops.

There are a number of highly regarded sauvignon blancs that were not included in the tasting. Among those that have received recognition in other recent tastings are several from Santa Ynez, Chateau St. Jean, Round Hill, Parducci, Montevina, Stonegate and Cakebread Cellars.