A series of bline tastings of varietal jug wines conducted by The Washington Post proved disappointing. In most it was difficult to discern varietal qualities. Time and again expectations were not met. As price often exceeds that for generic jugs - chablis, rhines, mountain reds and burgundies - there is reason to conclude that the varietals are not good buys.

Generic wines have played an important part in the growth of the American wine industry. The vins ordinaries have gained a justified reputation for drinkability and consistant quality. Varietal wines, on the other hand, are the industry's showcase products. Cabernet sauvignon and pinot chardonnay from California, for example, have won tasting laurels in competition with the best Europe has to offer.

Anyone attracted by the Pied Piper of the wine world is expected to begin with generics (or, for some, pop wines) and "graduate" to varietals. Varietals are the "serious wines." They tend to be more complex and more expensive. The grapes they come from cost more to plant and yield less. Often they are drier (less sweet) to the taste buds than generics. Win aficionados sniff them deeply and win writers are challenged to compose prose poems to them. Gnerics are for picnics and varietals are for sniffing, they believe.

Thus, until the wine revolution in this country varietals were largely the preserve of committed wine drinkers and wine snobs. Except for celebrations and gifts, the rest of the world drank generics. Then America's taste in wines turned from sweet to dry; new plantings of varietal grapes overtook the Thompson seedless and there was a push of varietals into the mass market. Gallo led the way, making millions of Americans aware of varietal names through massive advertising campaigns. Firms already producing varietals benefited; others jumped on the bandwagon.

The next step was logical. For economic reasons both producers and consumers became fond of the outsized bottles: the half-gallon or gallon "jugs." Yet varietals had been marketed almost exclusively in 1/5the bottles. Why not, the reasoning went, offer the public the status of varietal quality packaged in the economy symbol of a jug? The industry did, and although the practice still is relatively recent, sales figures indicate that varietal jugs are a success.

But what of quality? Is the consumer really getting his or her money's worth? Is the product what the label would lead you to believe - a distinct, recognizable representative of a grape family? Is it more than Hearty Burgundy, or just another name?

The wines that were tasted bore celebrated grape names: In Europe pinot chardonnay, chenin blanc and caberent sauvignon make some of the best and most expensive wines Zinfandel, once utilized in California mainly for blending, has the ability to produce a wine of great character and distinction. Yet California law allows a manufacturer to place a varietal label on a wine that contains only 51 per cent of the named variety. There are no further qualifications.

Therefore, a technical minority of zinfandel can dominate a "cabernet sauvigon," or a minority of Thompson seedless can virtually neutralize the qualities of a "pinot chardonnay." To some wine experts the names give a false legitimacy to the wines. To consumers the prices (from $3 to $5 or higher) give them reason to expect more. To our panel of tasters the "more" wasn't there.

"You are not going to find a great bottle of wine in a jug," said a local merchant. The truth of that statement became evident as scores were compiled. The chardonnay wines were easier to drink for those who prefer dry wines, yet the best of them was a "ringer," a French chardonnay from Macon. It clearly outdistanced the closet competition. It costs more, too, but the subjective judgement was that the price spread did not equal the quality difference.

There is another important facet of jug wine "economy." To realize full value, it is necessary to drink the full bottle. Wine merchants report frequent instances of customers returning after a week or so with a gallon jug they claim has "gone bad." Exposed to air, any wine will go off within a relatively short period of time. It is true that most manufacturers of jug wines use chemicals - legally - to purify and stabilize their wines. No matter. Evan with refrigerator storage, the wine in a jug - exposed to more and more air as more of the contents are drunk - will begin to turn within a few days. It should if it really is wine.

One recommended solution is to buy jugs and decant them into smaller bottles. Few people take the effort to follow this procedure, so the economic advantage of the jug often is poured down the drain or consumed unknowningly. The latter event can only stimulate soda pop sales. Unless wine is consumed regularly and in some quantity, a household probably is better off buying a case of standard-sized bottles.

As a generality, the wine tasted by The Post's panel lacked character. The chardonnays were distinctly drier than the chenin blancs, but far short of the crisp clarity one expects from top flight chardonnay grapes. The chenin blancs varied enormously but even the best of them obtained little more in the way of praise than words such as "pleasant." Among the reds, the cabernets were often cited for their zinfandel qualities as the latter grape, less expensive to raise or buy, plays a major role in blending cabernet. Among the zinfandels, ironically, the zinfandel quality was hard to find. Even cheaper grapes go into that blend.

None of this means the jug varietals are undrinkable. It does seem to indicate, however, that they fall short of being a significant step up the quality ladder from generic jugs; that for relatively little more - or even for much the same price - domestic and foreign wines in standard bottles may represent more pleasure; that unless consumed before the wines turns, they represent a false economy.

These jugs come in several sizes. To avoid confusion, the chart lists the bottle size, but does not give a cost per ounce break down. For those who wish to attempt some computation, a gallon jug contains 128 fluid ounces, a half-gallon 64 fluid ounces and the magnum or 1.5 liter jug contains 50.7 fluid ounces.

As with all wine comparisons conducted by The Washington Post, the wines were tasted "blind." Because of the distinctive shape fo some jugs, they were decanted into litre containers. Tasters did not know the identity of the wines they were rating and could not guess from bottle shape. Scoring was done on a basis that would award 20 points to a perfect wine of the type under consideration. The scores shown on the chart are an average of those awarded by the tasters. Comments from individual tasters are separated by semi-colons.