IMAGINE, THREE wondrous evenings devoted to tasting 19 different vintages of one of the world's greatest and most expensive wines. The event, a vertical tasting of the wines of Chateau Latour, was arranged by Paul Evans, one this area's most knowledgeable private wine connoisseurs and a fanatical devotee of wines of Chateau Latour.

Latour is located in the commune of Pauillac in the area north of the city of Bordeaux known as the Medoc. Its stature and prestige in the world of wine were assured in 1855 when it was accorded the very highest status in a five-tiered hierarchy of 61 top bordeaux wines. Only three other wines were proclaimed to be among the finest or premier grand cru classe, and these other first-growth bluebloods include the fabulously expensive chateaux of Lafite Rothschild, Haut Brion, and Margaux. Since 1855, only one change has been made to this archaic classification of wines, and that was the elevation of Mouton Rothschild to "first growth" status in 1973.

The 1855 classification of the wines of the Medoc is a subject unto itself, yet is sorely in need of revision, so its importance from a consumer's perspective is largely of historical significance only. However, the specific rating given a chateau does, in fact, dictate the price consumers will ultimately have to spend for that wine, regardless of the wine's quality.

Like its other frist-growth stablemates, Latour is very expensive and highly prized by connoisseurs and collectors. Unlike the other first growths, Latour has a reputation for consistent excellence year after year regardless of the vintage conditions.

What makes Latour so excellent year after year? First, the Latour vineyards are strategically located on a grevelly ridge adjacent to the Gironde. This stony location provides excellent exporure and drainage. Secondly, and most importantly, Latour practices modern, but very conservative winemaking methods. Only the highest quality cabernet sauvignon, merlot and petit verdot grapes are harvested, and only those barrels or cuvees of wine that show exceptional depth and, as the French say, finesse, are chosen for the Latour label. Unlike many other famous chateaux, the management at Latour divides each vintage's wine into three separate lots. The finest is set aside for the Latour label. The wine that is left is bottled under the secondary label, Les Forts de Latour, which is usually an extremely well-made wine -- one of the better wines of Bordeaux -- even though it has no official pedigree in the 1855 classification.

Latour has utilized modern stainless-steel temperature-controlled fermentation equipment since 1964, but still adheres to old-style fermentation methods. Skin contact with the grape juice is still 20 to 24 days, which is approximately a week longer than other chateaux in Bordeaux. This longer "vatting period intensifies the wine's character as well as imparts a healthy dosage of tannin necessary for the winehs longevity. The wine is aged in new oak barrels for up to two years, an incresingly expensive proposition, as each barrel now costs $300. All of these practices result in a powerful, darkly colored wine which is probably the longest-lived unfortified red wine in the world.

Like a thoroughbred horse that starts slowly out of the gate but wins each race by several lengths, Latour rarely exhibits its complexityu and depth until it is 8 to 15 years old. At 20 to 35 years of age, when most other bordeaux wines are lapsing into a senile coma, Latour is at its best, displaying a majestic richness and multidimensional texture which are only present in the greatest wines.

Armed with this knowledge of Latour, I and five other fanatics sat down for three days of tastings. My personal pre-tasting preparations were outrageous, but nevertheless necessary, considering the importance of the event. Several weeks prior to the tasting, I became so irrationally fearful of getting the flue or a miserable head cold, that I commenced each day with aspirin and vitamin C supplements to ward off any evil spirits. I took particular care not to get chilled after my daily exercise routine, and lived on a extremely bland diet immediately prior to the tasting so as not to upset either my stomach or my palate.

Finally, the tasting date arrived as did I with my palat, mind and body in top shape for the event. Each of the three tastings was conducted in chronological order from the youngest Latour (1976), to the oldest Latour (1921).

The most disappointing wines of the tasting were the 1972, 1921, 1969 and 1973 Latours. All of these vintages produced miserable wines, and while the Latours were probably among the best wines of the respective vintages, they are, at best, mediocre wines. Of the 19 different vintages, there were seven sensational vintages for Latour. The 1961, 1959, 1966, 1970, 1975, 1955 and 1967 Latours were power-packed, monumental bottles of wine, all with extraordinary aging potential and the promise of greatness. The group favorite was the 1961, a mammoth wine with incredible intensity and extract, although I marginally preferred the 1959 because of its exceptional combination of power and elegance. With the exception of the 1955 and 1967, all of these top Latours will last another 25 to 30 years and probably longer, if stored under ideal cellar conditions. Of the other wines tasted, the 1971, 1964, 1952 and 1962 were regarded as very good to excellent bottles of wine, but overshadowed by the top seven Latours.

What does a great Latour smell and taste like? Generalizing the tasting notes of the best vintages of Latour into one concise description would read as follows . . . "Dark ruby red, with a full intensity, ripe fruity aroma of fresh black currants, English walnuts, truffles and a subtle iron-like mineral scent; full bodies with rich; high-intensity flavors superbly balanced by firm acidity and a solid lashing of tannin, with a lengthy and deep finish."

The final judgment of the group after tasting 19 vintages was that Latour's reputation for consistent excellence was not only deserved, but probably understated. In any given vintage, a Petrus, Lafite Rothschild, Mouton Rothschild or Cheval Blanc may be finer or slightly more "complex," as the experts say, but if success and greatness are to be measured by excellence year after year, Latour has no peers. WINE BRIEFS

Get ready for Cellukork! Wine visionaries have for some time been predicting the demise of the cork-finished bottle of wine. While cork prices have continued to skyrocket, cork shortages and lower quality have caused further problems. Aluminum screwcaps and white plastic stoppers are used for the cheapest wines, but producers of so called "fine wine" have continued to use cork.

The newest invention on the market looks like cork and feels like cork, but this "kork" is made of ethylene-vinyl-acetate-copolymer. Imported from England by Loral Packaging Inc., Cellukork is supposed to do everything the real cork can do and has the advantages of unlimited supply and of being anathema to rapacious worms and mold.

While a corkscrew will still be necessary to extract a Cellukork from the bottle, many in the wine trade doubt that consumers will be enthralled with anything less than a real cork in their bottle of wine.

Two new California wineries have released their first wines into the local market, and their opening entries are auspicious, to say the least. The best value is the Pine Ridge 1978 Napa Cabernet Sauvignon for $8.99 a bottle. It is a big, rich supple wine for drinking over the next 5 years. Consumers with patience should look into the more expensive William Hill 1978 Napa Cabernet Sauvignon at $15.95. This large-proportioned wine has considerable promise if held for 5 to 10 years, and its brooding, powerful personality gives it a likeness (a la California style) to France's remarkable Chateau Latour. Unfortunately, the above two wines are currently available at only two shops in the District, MacArthur Liquors and A & A, but supplies are said to be good.