IN THE decade of the '70s, California wineries proved that they could produce wines that could compete with the finest made anywhere in the world. Will the decade of the '80s prove as I rewarding for East Coast wineries as the '70s were for wineries on the West Coast? If Byrd Winery's 1980 offerings of chardonnay, sauvignon blanc, gewurztraminer, seyval blanc and cabernet sauvignon are indicative of the quality we can hope to expect from the better East Coast wineries, the '80s could indeed prove to be a watershed decade for East Coast wines.

Byrd Winery, located in the Western Maryland foothills of Frederick County, has been producing wine since 1976, but it is their 1980 crop that will have wine aficionados buzzing about the obvious potential for fine wine from East Coast wineries.

Bret Byrd, still a full-time pharmacist in nearby Frederick, and his wife Sharon planted 75 vines in 1972 on their steep, picturesque Napa Valley lookalike location. By 1976 they had a total of 24 acres under vine, planted in both the French-American hybrids of seyval blanc, chambourcin and vidal blanc, and the vinifera varieties of chardonnay, sauvignon blanc, gewurztraminer, cabernet sauvignon, merlot, cabernet franc and johannisberg riesling.

Bret Byrd's aspiration from the beginning was to produce world-class wines from vinifera grapes, a rather bold objective since the East Coast has proven to be a graveyard, rather than a vineyard, for wineries that have planted vinifera varieties. Both the severe winters and short, frequently too-hot-and-humid growing season were the most common excuses given for vinifera failures on the East Coast.

Byrd's commitment to high-quality wine is immediately obvious from the significant monetary investment he has made in his vineyard and winery. A thoroughly modern operation with gleaming stainless steel, temperature-controlled fermentation tanks, a modern centrifuge and filtering machine, Byrd Winery has the look of a boutique California winery. In addition to Byrd and his wife, Byrd employs a full-time winemaker, Bob Lyon, a University of California at Davis graduate who has worked at both Cha teau Montelena and Domaine Chandon in Napa Valley, and a vineyard manager, Alan Willard.

Yet, as any serious wine buff knows, you can have the best location, best equipment and best people, but the bottom line is the product in the bottle. Byrd has indeed scored some triumphs with his 1980 wines, although skeptics of East Coast wine will no doubt argue that since 1980 was such an extraordinary year for East Coast wines, it was impossible to make a bad wine. However, close examination of the better East Coast vineyards has shown an increase in quality year after year from the vinifera varieties as well as from many of the hybrid grape varieties. Clearly the East Coast wine industry, the proverbial kicking boy for California and European wine snobs, is starting off the 1980s with a fine vintage under its belt and the promise of further excellence.

Byrd's production is about 2,700 cases per year, with a 10,000-case production projected when all vineyards are mature and able to produce at maximum capacity.

Byrd's 1980 whites are all cause for celebration among East Coast wine enthusiasts. His 1980 chardonnay is a rich, buttery, full-bodied (13.4 percent alcohol) wine with authoritative varietal character. Its style is clearly Californian with its rich, viscous flavors and spicy oakiness. There were 150 cases produced, and it is expected to sell for $9.99 to $10.99 per bottle. For lovers of trivia, the grapes were picked at 23.5 brix and the wine was aged for 3 months in new Limousin French oak.

The quality of Byrd's 1980 sauvignon blanc shocked me more than the quality of his chardonnay. Smokey, earthy and herbaceous, this wine has the look, smell and taste of a textbook sancerre from France's Loire Valley. It is full-bodied (12.4 percent alcohol), with lively acidity and a big, rich, full-flavored feel in the mouth. Only 273 cases were produced, and the price for this wine, which will be under $9 per bottle, has not yet been established. The last vinifera variety offered is a surprisingly spicy, dry-styled 1980 gewurztraminer. This elegant, medium-bodied wine resembles the French gewurztraminers of the Domaine Trimbach in Alsace. Only 17 cases were produced, and this wine will be sold only at the winery, at a price that has not yet been established.

Byrd's white hybrids also are very successful in 1980. His 1980 seyval blanc ($5.49) is his best yet, with a clean, bone-dry fruitiness, medium body and a resemblance to a well-made French muscadet. The nonvintage seyval is made from purchased grapes, but they are all from the remarkable 1980 vintage. At $3.99, it is one of the best white wine bargains on the market, and the new rendition (bottled in May 1981) is much drier and vastly superior to previous Byrd nonvintage seyvals, which I thought were cloyingly sweet and dull.

While Byrd's 1980 whites are reason enough to take a keen interest in local wineries, his 1980 cabernet sauvignon appears to be a winner as well. While it will not be bottled until spring 1982, the wine is dark ruby purple, with intense cassis herbaceous flavors and mouth-puckering tannin. It is distinctly French in style and should prove to have considerable aging potential when released. Byrd's 1979 cabernet sauvignon is less intense and still suffering from malolactic fermentation, making evaluation virtually impossible. And I found his red hybrid chambourcin disappointing, hardly a wine to merit consumer interest.

The Byrd Winery is about a 90-minute drive from downtown Washington. It can be reached easily by taking I-270 North to Frederick, where I-70 West (direction of Hagerstown) should be followed for several miles to the Myersville exit. All of the white wines are available at the winery. The reds have not yet been bottled. The winery is open from 1 to 5 p.m. Monday through Friday, and 1 to 6 p.m. Saturday and Sunday; it is closed on Tuesday. There is a $2 admission charge, which includes a tour, slide presentation and wine tasting.

WINE BRIEFS

Who are the biggest sellers of wine in America? E.J. Gallo continues to dominate the wine business with an incredible 121.9 million gallons of wine sold in 1980. United Vintners is second with 52.5 million gallons, Almaden third with 32.1 million gallons and Coca Cola's Wine Spectrum fourth with 22.4 million gallons. The only surprise in this quartet is the leap of the Wine Spectrum from number six in sales to number four. The Wine Spectrum also had $8.1 million in ad expenditures in 1980, much of it in the highly visible California Cellars comparative taste ads.

Looking for an interesting value in red wine? 1978 Tyrrell's Long Flat Red ($3.99 to $4.49), from the Hunter River Valley in Australia, is a soft, fleshy, fruity wine with much of the character of a French pomerol. It is ideal for drinking now and over the next one to three years.