If the American quality-wine boom could be traced to a single source, many would say that the copious, high quality vintage of Bordeaux 1970 was the catalyst. The vintages of 1966 and 1967 provided significat stirrings, and a good deal of money was invested in the disappointing '69 Bordeaux. But the 1970s were the first high quality clarets for a very large number of now-dedicated oenophiles.

At the time of harvest, the French and American trade labeled 1970 Bordeaux as a "vintage of the century." By 1974, the trade wasn't so sure. Accolades such as " excellent structure" were giving way to whisperings of "agreeable fruit -- but no backbone" and "limited aging potential." The succeeding years have allowed the rhetoric to clear. It was a superior vintage. In their tenth year, owners of these 1970 wines would be wise to open an occasional bottle to determine for themselves when these wines will reach their peaks. In an effort to assist these determinations, a report follows based on recent tastings.

Some general comments:

The development of wine in the bottle is closely related to the manner in which it is stored. Generally speaking, wine that is stored in a cool area at a relatively stable temperature ages more slowly than that stored in a warm area or one that subjects the wine to significant shifts of temperature. Each of the wines discussed below has been well kept.

Predictions regarding the future of a given wine are just that -- predictions. One of the most pleasant aspects of following the development of a given wine is that the wine periodically fails to follow the course set out for it by mere mortals. A given wine may develop more rapidly than expected, while another proceeds more slowly on its journey. While serious effort has been made to avoid misleading predictions, these are best seen as educated guesses, and should not be followed slavishly.

Finally, wine is a living organism and, as such, there may be differences from bottle to bottle from the same estate and year. This is known as bottle variation. Modern methods of production and sanitation have greatly reduced bottle variation, but have certainly not eliminated it. As wine grows older, bottle variation becomes a more significant possibility.

Gloria -- A lovely wine that is ready to drink. Soft and subtle with great depth of color and flavor, this wine must be near its peak. It has sufficient structure to last for at least four more years.

Ducru Beaucaillou -- Stunning wine. My choice as the finest St. Julien in a very fine vintage. There is as much fruit as the Gloria, but the wine is beautifully structured and posses more nuances of flavor. It can be enjoyed now, but will reward two or three years of patience.

Beychevelle -- Always a good win in good years, the '70 is no exception. To me, it is not as good as the Gloria of Ducru, but is a fine wine that can be enjoyed over the next several years.

Latour -- Traditionally, the most powerful of Paulliacs, this wine is progressing true to form. When tasted two years ago, the '70 Latour seemed to be opening a bit, but a recent sample indicates this wine is keeping is secrets hidden. The 1970 Latour will doubtless be a star of the vintage. All the signs are there. It has structure, fruit and backbone, but will only yield its potential if held for at least five more years. Resist the temptation.

Les Forts de Latour -- Only the makers of Latour itself could call this a "second" wine. Made from the fruit of young vines and casks that don't live up to the standard of le grand vin, , Les Forts is a predictor of how Latour itself will develop. It is first-class Paulliac. Deeply colored, firm and showing great depth of flavor, owners of this excellent wine can enjoy it now, though the wine will not peak for at least three more years.

Lafite -- Much has been written of the distinctive style of Lafite. Nearly every reference is to the feminine gender, doubtless implying race, sophistication and elegance. Another often-used reference is to the "breed" of Lafite. The 1970 Lafite is, indeed, elegant, but its fullness and fruit are most obvious now. Some will disagree, but I question whether this wine has sufficient structure to become as great as the '59 or '66 from this estate. The wine is very pleasing now, but three or four years additional aging will be well worth the wait.

Mouton -- Two years ago, this was thought one of the two or three best wines of the vintage. Lovely deep color, rapturous varietal aroma and cedar bouquet, deep and long-lasting flavors -- this wine had it all. About that time, I predicted true greatness by 1980 to '82. 1980 arrived, and my prediction was met by a very contrary wine. The color and structure are still there, but the wine seems to be going through a transitional stage. It has turned a bit inward and refuses to blossom fully just now. This is an unmistakably fine wine, but I would have to revise my earlier prediction and estimate that this wine will not be drinking well until at least 1983.

Lunch-Bages -- A fifth growth Paulliac noted for its firmness in youth, this wine is progressing true to early predictions. Currently hard and unyielding, '70 Lynch, too, has it all, but refuses to be rushed. Lovers of young California cabernet sauvignon will find this most enjoyable in the near future; but if aged, complex claret is your goal, give this one five years.

Grand Puy Lacoste -- This wine remains an enigma. A few years ago, I was ready to write it off as a big, clumsy wine with plenty of simple fruit but lacking in structure. My recent tastings have shown that there is definitely a backbone to this wine, but I am unable to state that the '70 Grand Puy Lacoste will develop into fine claret. In tasting wines such as this, I am always reminded of ugly ducklings and beautiful swans -- I'm afraid no one can yet tell if this story shall have a glorious ending. In any event, give it two or three years.

La Mission Haut Brion -- Several years ago, I believed that the '70 La Mission would be a perfect dinner wine for the year 2000. The wine epitomized the term extract. It was of inky, almost impenetrable color; long, full and tannic in the mouth; and had a developing, earthy bouquet typical of fine Graves. My recent tasting was prompted by reports from Europe that this wine was revealing unpleasant volatile acidity. My own tasting shows that ther is the slightest bit of VA present, as there is in all wine, but I found it not at all unpleasant volatile acidity. Further the wine is developing rapidly and will be stunning. The '70 can be enjoyed now, but true drinking pleasure is still two to four years off.

Haut Bailly -- At the urging of a very knowledgeable friend, I tasted the '70 Haut Bailly in Seattle recently. The Haut Bailly is ready now. It is charming and graceful, but could only be considred "light" if tasted in conjunction with some of the powerhouses already described. Nicely balanced, the wine should last for at least another year or two.

Palmer -- My early favorite as the best wine of the vintage. In its youth, Palmer showed extraordinary fruit and was lovely. In 1980, the fine varietal fruit is becoming more complex and is clearly passing through a phase. It can be drunk now, but two or three years will reveal a truly remarkable, if a typically full, Marguax.

Montrose -- The devotees of Mointrose are followers of the maxim that great wine does not develop overnight. Montrose and Latour are two wines that traditionally take longest to reach full maturity. Fortune favors the bold, but Montrose favors the patient. The '70 shows great breed, but simply isn't ready. Maybe 1985, maybe later.

Cos d'Estournel -- Another favorite from St. Estephe, the Cos is invairably softer and more forward than Montrose of the same vintage. '70 Cos d'Estournel is an elegant, subtle wine. It may be enjoyed now, but probably won't reach its peak of development for another two years.

Because several most knowledgeable professionals wrote that '71 Saint Emilions and Pomerols were of higher quality than their '70 counterparts, I bought very few '70's from either of these communes. I have, however, tasted some of these wines, and my assessment is that the '70s, while lacking the engaging fruitness of the '71s, will probably be the longer-lived and more distinctive of the two vintages.

Petrus -- In our years, this is probably the most expensive of the wines of Bordeaux, with price levels eclipsing even those of Lafite of recent vintages. The '70 is splended wine, each bottle worth a small fortune. If you have but one or two, don't open the first until 1984 or '85. At that point, it should be magnificent.

Trotanoy -- Very similar to the Petrus, at less than half the price. This wine can be drunk with great pleasure now, but will continue to improve in the bottle for at least another three years.

Figeac -- The most Medoc-like of the wines of St. Emilion, this splendid claret has a relatively high proportion of cabernet sauvignon in its blend. Two different bottles sampled recently led me to conclude that this wine is in a phase and should be aged at least another year before drinking.

With literally hundreds of classified growths, a complete explication of the state of the 1970 vintage Bordeaux is not possible. However, there are patterns that emerge and may serve as good rules of thumb for trying to decide wheter a particular bottle is ready to drink.

Estates which make big hard wines, such as Latour, Montrose and Lynch-Bages are at least five years from their peaks. Those who make full, but less tannic wines, such as Palmer, Lafite and Figeac can be drunk in the near future, but will not provide maximum enjoyment until at least a year or two. Finally, those estates which regularly turn out soft and less sophisticated clarets, such as Haut Bailly and Gloria, can be drunk now but should increase in quality over the next several months. Included in this latter group would be the numerous growths classed as very good -- but not great -- growths, such as Fombrauge, D'Angludet and Fourcas Dupre.