There is no question that sharing a well-preserved 15- or 20-year-old bottle of wine with appreciative friends can be a gustatory and olfactory delight. A tiny portion of the world's wines -- mostly French bordeaux, burgundy and rho ne wines, Italian reds from the Piedmont and Tuscany sections, and some California cabernet sauvignons -- benefit enormously from long-term cellaring, which can transform something that was raw and ungenerous in its youth into a magnificently rich and velvety wine 15 or 20 years later.

Knowing that the finest wines do such things, thousands of wine enthusiasts squirrel away quantities of wine for drinking in 10, 15 or even 25 years. Provided they have cool, dark, humid, odor- and vibration-free places to keep such vinous treasures safely, this is clearly the least expensive way for most wine lovers to enjoy fine old wines.

For others with the discretionary income, or sufficient passion, but not the patience, older, more mature vintages can be found at wine auctions and occasional wine retailers. On the surface, buying fine, old wine when it is fully mature seems logical enough, since no money need be tied up for more than a decade in a young wine, and storing the wine in a suitable abode is not a worry.

However, your local wine merchant is not likely to have told you about the many risks in buying older wines. Unfortunately for the wine consumer, a surprisingly high percentage of old wine sold is damaged by poor storage. Such damage can turn a wine completely brown in color and oxidized and quite unpalatable. Buying old wine of unknown history is like buying the proverbial pig in a poke. The rule caveat emptor should be particularly observed when entering the old-wine buying lottery.

First, this county's importers, distributors and merchants have traditionally regarded wine as simply another branded alcoholic beverage. Wine is a very fragile, living beverage, and while young, virile, tannic and concentrated vintages can take surprising amounts of abuse, older more mature wines are very susceptible to poor storage.

Several books could be filled with horror stories about fine old wines shipped in unrefrigerated trucks or boats in the torrid August heat, only to arrive at their destination totally destroyed with wine seeping out around the cork and the prospect of a magnificent gustatory experience killed by negligent handling. Even when fine old wines arrive at their selling point in a healthy condition, there is no guarantee that they will be handled properly by the distributor or merchant.

Last July I visited a famous New York merchant early on a Monday morning when the store opened, and inside the shop it was at least 90 degrees. The air-conditioning had been turned off at 4 p.m. Saturday when the owner went home. It was shocking that a merchant specializing in older vintages would be so cavalier toward the handling of these wines, especially given the prices and quality of his inventory.

On another occasion, a hot September day, I was shocked to see cases of 1970 La Mission Haut Brion (a magnificent wine) piled very high under a corrugated metal roof in the back of a local warehouse roasting in what had to be a temperature in excess of 90 degrees. Pity the poor consumer who purchased this expensive wine hoping for a remarkable drinking experience and received, no doubt, something that was more kin to salad vinegar.

When buying older mature vintages of fine wines, observe the following rules:

(1) Try to learn something about the wine's history, where it was stored and who had it before it was offered for sale to you.

(2) Examine the wine closely. Wines that have been poorly stored often have low fills and bad corks, not to mention brownish colors. Hold the bottle next to an incandescent light and look at the wine through the neck. You can expect to see some brown-orange tints in a wine over 12 to 15 years old, but if the color is rust, back off. Feel the cork. If it is firm and tight, that's a good sign. Also look at the fill level. Wines that have ullage below the neck level must be approached with extreme caution.

(3) Examine the vintage. Wines from vintages that produced deep, rich, concentrated tannic wines age better and can take more abuse and mistreatment than wines from lightweight vintages. For example, bordeaux vintages such as 1945, 1947, 1949, 1959 and 1961 have aged well because they produced very powerful, rich, concentrated and tannic wines. However, for years such as 1953, 1955, 1962 and 1971 be sure that the wine has been perfectly stored because these wines are significantly lighter and less tannic and often any kind of mistreatment during their lifetime results in these wines turning into expensive vinegar.

(4) Don't be turned off by either a lot of sediment in the wine or a tattered, mildew-spoiled label. Sediment in an old wine is to be expected and is a natural development. Be more concerned if there is no sediment, in which case the wine may be a total fraud or been put through such a fine filtering machine that there is really no flavor left. Good wine cellars tend to be damp. Dampness is anathema to paper labels on wine bottles. Old, mildewed labels could very well be a sign wine has been stored very well.

Happy vinous hunting -- but be careful.