A BUYER may be disappointed in a wine he has purchased because he dislikes its style or it has been poorly made. Or the problem may lie farther along, in the wine being defective due to faulty handling of the bottle. Often that disappointment can be prevented by careful inspection of the bottle before buying.

One of the most commonly encountered wine defects is the cooked or baked wine, often the fault of a dwindling but significant number of importers, wholesalers and retailers who treat wine as though it were a bottle of soda pop.

While extreme sub-freezing temperatures can be harmful to wine, heat is wine's major killer. Wines exposed to high temperatures tend to maderize quickly, taking on a vinegary aroma and hollow, burnt, cooked flavors. This problem of wine burnout is exacerbated by wine shipments in mid-summer from Mediterranean port cities in Europe and truck or rail convoys across America's torrid southwest and midwest regions.

Rarely are wines sent in temperature-controlled containers, although the most-conscientious importers and retailers who ship wines in the heat of summer do require shipment in special insulated containers. Numerous European wine brokers will only ship wines in the fall and spring, when the temperatures on both sides of the Atlantic are moderate and the risk of excessive heat or cold is minimized.

Even if the wine survives its hazardous journey to the local wholesaler, it may still be deprived of its vital life signs before being poured into the consumer's glass. Unfortunately, few wholesalers maintain temperature-controlled wine rooms.

A visit to a warehouse in mid-summer can be a nightmare for the wine enthusiast who purchases wines on the assumption that a wine is in good health. On a tour of a wholesaler's warehouse facility one August I saw thousands of cases of wine awaiting sale. As I was perspiring, I guessed that the temperature inside the warehouse was probably in excess of 85 degrees.

In addition, this particular warehouse had wines, many of them expensive bordeaux and burgundies, stacked to the roof. I could only surmise that the temperature up near the roof must have been 10 to 15 degrees warmer than on the floor level. Any wine stored in such conditions for more than several days would be irreparably damaged.

Let's assume a wine makes it across the country, or arrives in port in good health, survives its stay at the local wholesaler's, and finally ends up at a retail shop in excellent condition. The chances are, after avoiding all those hazards of its perilous journey, the wine will be placed standing upright on some shelf.

No one seems to know how long it takes for a wine's cork to dry out and the fairly rapid maderization process to take place. However, a good bet is that any wine left standing up for over a month is going to show some signs of early senility as a result of having its all-important life plug--the cork--dry out and admit hazardous air to the contents.

How does the consumer know the bottle of wine has been exposed to excessive heat for a prolonged period? Unfortunately, most signs of wine burnout are not apparent until the cork is pulled. Yet careful visual inspection might reveal enough telltale danger signals to allow you to steer clear of such a bottle.

Sometimes a wine that has been exposed to high temperatures will expand and seep up and around the cork enclosure. Small streams of dried, sticky wine will be noticeable around or below the lead or plastic capsule covering the cork. This is not always a sign that the wine has been kept in hot storage, as sloppy bottling operations also can produce the same signs.

Another type of visual inspection that can reveal potentially flawed bottles is made by holding the bottle up against an incandescent light source and inspecting the wine in the neck of the bottle closest to the cork. If you can see a great deal of brown and orange in the color, then there is no doubt the bottle is prematurely passed its prime. Of course, older bottles of red and white wine will have amber or brown edges to them, but young wines should be brilliant ruby red or deep ruby in color with no sign of browning.

White wine should be clear, brilliant light straw or light greenish-gold, but never amber or sherry-like in color. One problem with this test is that very few wine shops have any incandescent light source available for consumers to perform this examination on a suspicious bottle.

A third test for disclosing cooked bottles of wine is to look at the very top of the lead capsule which covers the cork. Wines that have been poorly treated, especially if they have been exposed to very high temperatures, will expand, creating enough pressure so that the cork will be pushed out of the bottle by as much as 1/2 inch. Some retailers never notice this or, worse yet, don't realize what such a sign means, thus their poorly handled bottles are obvious. Other, more knowledgeable retailers, simply take rubber mallets and gently knock the cork back in the bottle. Yet, you can still spot such a bottle.

Most imported wines with lead capsules have the name of the wine, shipper or trademark printed in raised lettering on the top of the capsule. Once hit with a hammer, no matter how gently, these raised letters will not be readable, and usually some of the paint on top of the capsule will be chipped away. If you spot such a capsule, back off.

Fortunately, the incidence of cooked, young bottles of wine is not yet a great problem; on an average, I suspect, one in every 50 bottles of newly released young wine is affected. With older vintages offered for sale by retailers and auction houses, I suspect a good 33 percent to as many as 50 percent of such bottles have been mistreated in some manner. This is despite the efforts by auctioneers to ascertain the lifeline and background of the particular wines being offered for sale. My tastings of older bordeaux have confirmed that many bottles purchased through auctions or retailers reveal the telltale signs of burnout.

Locally, the problem of burnout does exist, although several local wholesalers maintain temperature-controlled wine rooms. In addition, the better retailers seem to be more cognizant of the problem, taking precautions to store their wine properly on its side and to keep it away from excessively warm areas during the heat of the summer.

Yet, wines will continue to burn out, and the best advice is to deal with a retailer who is as careful about buying and storing wine as you are about choosing it.