Ever wonder why they put stems on wine glasses? For you to use them, that's why. If you hold your glass by the bowl, you�re likely to change the temperature of the wine. You also block your view of the wine. Not only is seeing the wine part of its attraction, it's also part of evaluating it. If a wine doesn't look good, it probably isn't good. The glass, by the way, should be clear, not tinted.

So the first step in evaluating it is to look at it. Preferably over a white tablecloth in a well-lit room. Tilt the glass a bit and look through it, noting color and density, checking it for brilliance, viscosity, and opaqueness or clarity. Take notes or assign points or both.

Twirl the glass gently in your hand or rotate it in a circular motion on the tabletop. This causes the wine to aerate a bit in the glass and to release its fragrance. Then bring the glass to your nose and sniff several times in short bursts. Try to "feel" the aroma, interpret the bouquet, compare it with flavors you can recognize. Judge it for freshness, fruitiness, sensual aspects. That, by the way, is why a wine glass has a kind of tulip shape -- to allow your nose to sense the wine as you raise it to your mouth. Take notes or assign points or both.

When drinking purely for pleasure, pour a white wine till the glass is two-thirds to three-fourths full, a red wine to about half full so that you have space for a bit of a twirl. If pouring just to judge, an ounce or two will do.

Time to sip and slurp. As you bring the glass to your lips, continue to sniff as you sip enough to coat your entire mouth. Slurp the wine around to make sure it engages all the senses on the tongue and in the mouth -- sweet, salt, bitter, etc. Form an impression of the initial impact before swallowing.

After swallowing, pay careful attention to the length of time the wine lingers in your throat. This is known as the "finish," which is often described as long or short. Long is good; short may not be bad but indicates a wine of less complexity and quite possibly quality. Again, take notes or award points or both, recalling the initial taste impression (separate points) as well as the finish.

A review of your notes or point totals gives an indication of how you judge the wine and whether or not you wish to buy more of it or recommend it to a friend or colleague. There are many points systems: Wine Spectator and Robert Parker use 100 points, the International Wine and Food Society uses seven points. Julia Childs' husband noted only "no," "good," or "excellent."

Once opened, how long can you keep a bottle? Not very long, but with the cork back in place, the bottle in a cool place (including the fridge), nearly all wines will keep till next day, some even another day. And while professionals may rate a hundred or more wines a day, we suggest beginners not try more than four or five at a time and not swallow more than a sip or two of each until the ratings are complete.