Can fine wine come in screw-top bottles? Will a bag in the box keep a good wine from going bad? Is a cork the sine qua non of quality? In short, how does one choose among the multitude of jug wines on local retailers' shelves?

These are the wines most of us buy for office parties, casual afternoons or evenings with friends, or an everyday dinner at home where the best is neither demanded nor perhaps appropriate. Price is the major consideration, but that doesn't mean we don't want the wine to taste good, or at least as good as the party budget or office kitty allows.

In tasting nearly 70 examples of the most popular (and not-so-popular) jug wines, I discovered that selecting a jug wine is really no different from shopping for any other type of wine. The selection is huge, information is scant, and ultimately, it's up to you to decide what you like or don't like.

To help you find the pearls, or at least the cultured pearls submerged beneath what I would describe as an ocean of mediocre-at-best wine, here are some pointers:

California's jug wines, both red and white, are typically very fruity, and lusher, riper and softer than French offerings.

French jug wines are lighter, crisper and more austere than California jug wines.

California wines with French sounding names (e.g. "Le Blanc") taste like California wines.

The best values in jug wines today are at the premium end of the jug category, mostly from California in vintage or non-vintage varietals, such as chardonnay, cabernet or sauvignon blanc, or premium blends of top varietals. The Golden State's vintners would prefer not to have to sell you a magnum (1.5 liters) or more of wine this good for $6-$7, but they have to because of the glut of good varietal fruit now. The lake is said to be drying up though, so it's best to take advantage of it now while we still can.

The bag-in-the-box container (an elastic bag inside a cardboard box that contracts as the wine is consumed, keeping air away from the wine) really does keep wine fresher for longer, as claimed on the box. An open box of Almaden Mountain Chablis stayed in my refrigerator for almost three weeks without any noticeable deterioration in quality. Unfortunately, it didn't get any better either.

French generic reds usually resemble a cross between a beaujolais and a co~tes du rho~ne, but tend to be heavier and less lively than either.

Ignore the word "dry" on the label of a large-size (i.e three or four liter) California generic wine (e.g., chablis or burgundy). The majority of these wines are noticeably sweet, averaging about 1.5 percent residual sugar, well above the tasting threshold for sweetness. One exception is Inglenook's Navalle Blanc de Blanc, which is labeled "very dry." It was only slightly sweet.

With nonvintage jugs, buy only fresh-looking stock from a retailer with high turnover or, if you patronize a less busy shop, ask the proprietor to order a fresh case to assure the youngest possible wine. Wines that cost $5.99 for a four-liter jug do not improve with age.

A prominent downtown restaurant charges $3.50 for a 6-ounce glass of its house wine, a Petri jug burgundy that costs it a grand total of 25 cents per glass by my calculation. Be forewarned: this is a common practice. Inquire as to the house wine before ordering.

A clue to the style of a red jug wine is whether it is vintage dated. Such wines have usually been aged in wood and have mellower flavors and bouquets. If fresh, robust fruitiness and, often, grapiness is your style, stick with nonvintage.

Exercise extreme caution when opening a bag-in-a-box wine with a sharp object. A paper towel moistened in white wine will often remove red wine stains from a light-colored shirt.

The tasting notes that follow are for the top dozen jug wines, based on offering the best combination of quality and value in their price categories. Except where noted, wines are nonvintage. Though most wineries aim for consistency, nonvintage blends can vary from shipment to shipment. Your retailer may order a wine through the wholesaler listed in parentheses. Prices are approximate.

White Jug Wines Gallo 1984 "Limited Release" Sauvignon Blanc ($4.50-$6.50, 1.5 liter; California): Gallo is serious about moving into premium varietals, and this is a surprisingly flavorful Loire-styled sauvignon blanc with a fresh, grassy bouquet and good intensity. Use with fish or chicken. (Forman)

Torres Vina Sol 1985 ($6, 1.5 liter; Spain.): Perfectly refreshing, clean, dry chenin blanc-like flavors, with excellent acidity. (Kronheim)

San Martin Chardonnay ($6-$7, 1.5 liter; California): Crisp, light style with clean chardonnay varietal character. Once content to custom crush (make wine to order) for some of California's big name wineries, San Martin is now striking out aggressively on its own under the clever winemaking of enologist Ron Nino. (Forman)

Inglenook Navalle "Blanc de Blanc" ($6-$7, 4 liter; California): Finally a large-format, California chablis-style wine that is dry, or at least very close to dry. Very grapy and too light, but clean, refreshing, with a pleasing peach scent. (Kronheim)

McDowell Valley Vineyards 1985 White Table Wine ($6.50, 1.5 liter; California): Robustly fruity, lively, with a zip of CO . (International)

Moreau Blanc ($7, 1.5 liter; France): The clear winner over the other French generic whites (at least the current shipments). Mineral scents and steely flavors call to mind a petit chablis. Fine choice for seafood or mussels. (Forman)

Red Jug Wines Duboeuf "Cuve'e George Duboeuf" Vin Rouge ($6, 1.5 liter; France): Resembles a good beaujolais village at half the price; bright purple color, exuberant, lively gamay fruit and ripe flavors. Great summer red. (Washington Wholesale)

Torres 1983 Sangre de Toro ($6. 1.5 liter; Spain): Super value in hearty Rho~ne-style red, lush flavors, good concentration and a oaky, spicy, ripe bouquet. (Kronheim)

Colony Cabernet Sauvignon ($6, 3 liter; California): Good everyday cab, at $2 a liter or less delivers some varietal character, good color, and clean, pleasant flavors.

Gallo Hearty Burgundy ($4, 1.5 liter; California): Dark purple color, impeccably clean, grapy flavors, and very smooth. Don't send back your Le Chambertin if it doesn't taste like this "burgundy," however. (Forman)

Robert Mondavi 1984 "RM" Red Table Wine ($6-$7, 1.5 liter; California): Decidedly in the Mondavi house style, this cabernet has smoky, minty ripe fruit. (Forman)

Monterey Vineyard 1982 or 1984 Classic Red ($7, 1.5 liter; California): Oaky, cedary, ripe style of mostly cabernet wine, the 1982 has more finesse and fruit, but the 1984 offers good drinking also. (Washington Wholesale)

The following wines were also tasted. Those marked by an asterisk offered above-average quality for the price. First, the whites, listed alphabetically:

Almaden Mountain Chablis ($7-$8, 4 liter; California); *Barefoot Bynum Premium White 1985 Sonoma Sauvignon Blanc ($7-$8, 1.5 liter; California); Canteval White ($6, 1.5 liter; France); Chamboustin White ($6, 1.5 liter, France); Chantefleur Blanc de Blancs ($4-$5, 1.5 liter, France); Chantovent Blanc ($6, 1.5 liter; France); Concha y Toro 1986 Sauvignon Blanc/Semillon ($4-$5, 1.5 liter; Chile); *Cribari Chardonnay ($7, 1.5 liter, California); Cribari Fume' Blanc ($6, 1.5 liter, California); Cuve'e Bistro 1985 Corbie`res Blanc de Blancs ($4-$5, 1.5 liter; France); *Duboeuf "Cuve'e George Duboeuf" Vin Blanc ($6, 1.5 liter, France); Fetzer 1985 Chablis ($6, 1.5 liter; California); Glen Ellen Proprieter's Reserve White ($6, 1.5 liter; California); *Inglenook 1984 Napa Valley White ($7-$8. 1.5 liter; California); Inglenook Navalle Chablis ($7-$8, 4 liter; California); Le Blanc Chablis ($5-$6, 4 liter; California); L'Espayrie Blanc de Blancs ($7, 1.5 liter; France); *Mirassou 1985 Dry White ($7-$8, 1.5 liter; California) *Robert Mondavi 1985 "RM" White ($6-$7, 1.5 liter; California); Mont Lata Salle Chablis ($8, 4 liter; California); J.W. Morris 1985 White Private Reserve ($5, 1.5 liter; California); J. Pedroncelli Sonoma White Wine ($6, 1.5 liter, California); Pe`re Patriarche Blanc de Blancs ($5-6, 1.5 liter; France); Riverside Farm 1985 Sonoma Fume' Blanc ($7, 1.5 liter; California); Riverside Farm Premium Dry White ($8, 4 liter; California); Romarets Blanc de Blancs ($5-$6, 1.5 liter; France); Sebastiani 1986 Country Chardonnay ($6-$7, 1.5 liter; California). Sebastiani Sonoma County Chablis ($7, 4 liter; California); Valbon White ($4-$5, 1.5 liter; France).

And the reds:

Almaden Mountain Burgundy ($6-$7, 4 liter; California); *Barefoot Bynum Premium Red Sonoma Cabernet Sauvignon ($7-$8, 1.5 liter, California); Canteval Red ($4-$5, 1.5 liter, France); Chamboustin Red ($6, 1.5 liter; France); Chantefleur Rouge ($4-$5, 1.5 liter, California); *Chantovent Rouge ($6, 1.5 liter; France); Concha y Toro 1984 Cabernet Sauvignon/Merlot ($4-$5, 1.5 liter; Chile); Cribari Cabernet Sauvignon ($6, 1.5 liter; California); Cuve'e Bistro 1985 Merlot ($4-$5, 1.5 liter; France); *Cuve'e Bistro 1983 Cabernet Sauvignon ($4-$5, 1.5 liter; France); *Fetzer 1983 Mendocino Burgundy ($6, 1.5 liter; California); Glen Ellen Proprietor's Reserve Red ($6, 1.5 liter; California); Inglenook 1982 Napa Valley Red ($7, 1.5 liter; California); Inglenook Navalle Burgundy ($6-$7, 4 liter; California); Le Blanc Burgundy ($5-$6, 4 liter; California); *McDowell Valley 1985 Red Table Wine ($6-$7, 1.5 liter, California); *Mirassou 1985 Red Table Wine ($7-$8, 1.5 liter; California); *Mont La Salle Burgundy ($8, 4 liter; California); J.W. Morris 1983 Red Private Reserve ($5, 1.5 liter; California); Pedroncelli Sonoma Red ($6, 1.5 liter; California); Riverside Farm 1982 Cabernet Sauvignon ($7-$8, 1.5 liter, California); *Romaret Red ($5-$6; 1.5 liter; France); Ruffino 1985 Chianti Classico ($7-$8, 1.5 liter; Italy); Sebastiani Mountain Burgundy ($7-$8, 4 liter; California); Torres 1981 Coronas ($7, 1.5 liter; Spain); *Trakia 1984 Merlot ($4-$5; 1.5 liter; Bulgaria); Valbon Red ($4-$5, 1.5 liter; France); Zonin 1984 Montepulciano di Abruzzo ($5, 1.5 liter; Italy).