You might think it's the easiest part, too. After all, you learned to drink from a cup when you were 2 years old and have been practicing diligently ever since. But there's a huge distinction between swallowing and tasting, the same gulf that yawns between simply hearing and truly listening. Once again, correct technique is essential to full appreciation.

With the aromas still reverberating through your senses, put the glass to your lips and take some liquid in. How much? That depends on the size of your mouth. But too little is as ineffective as too much. About one-third to one-half an ounce is just about right. You need to have enough volume to work it all around your tasting apparatus, but not so much that you're forced to swallow right away.

Because you don't want to swallow, not just yet. It takes time and effort to force the wine to divulge its secrets. I keep a pleasant wine in my mouth for 10 to 15 seconds, sometimes more.

Roll the wine all around your mouth, bringing it into contact with every part, because each decodes a different aspect of the liquid. Wine provokes sensations, too: The astringency of tannins is most perceptible on the inner cheeks; the heat of the alcohol burns in the back of the throat.

The strength of these taste sensations can be amplified through specialized techniques that, frankly, are more appropriate to the tasting lab than the dining room. But if the wine is seductive enough, you may not be able to resist. First, as you hold the wine in your mouth, purse your lips and inhale gently through them. This creates a bubbling noise children find immensely amusing. It also accelerates vaporization, intensifying the aromas. Second, chew the wine vigorously, sloshing it around in your mouth, to draw every last nuance of flavor from the wine.

Don't forget the finish. After you swallow, exhale gently and slowly through both your nose and mouth. The retronasal passage, which connects the throat and the nose, is another avenue for aromas, which can linger long after the wine is finally swallowed. You'll find that the better the wine, the more complex, profound and long-lasting these residual aromas can be. With great wines, sensitive tasters and minimal distractions, the finish can last a minute or more. It's a moment of meditation and communion that no other beverage can create.

Text from Wine Spectator's Pocket Guide to Wine. Image from www.chaineus.org.

Sipping Wine: Advanced Clues From Taste
When you finally taste the wine, the last evidence falls into place. Our taste buds are blunt instruments—most of what we "taste" is actually perceived by our sense of smell—but they do add basic information, particularly about sweetness and acidity. Just as important are other physical sensations perceived in the mouth, such as a wine's body, astringency and level of alcohol.

A wine's alcohol level results primarily from the ripeness of the grapes at harvest (more sugar in the grapes equals more strength in the wine) plus, where it's permitted, from additional sugar added during fermentation (a process called chaptalization). Most table wines contain from 7 to 14 percent alcohol naturally, and winemakers generally chaptalize where necessary to reach levels of 12 to 13 percent (though it's almost always illegal to boost a wine more than two degrees, or percent, through added sugar). Higher alcohol levels give wines richer textures and fuller bodies. Alcohol also provides a subliminal sweetness that's necessary to balance acid and bitter components inevitably present in wine.

Acidity is also inherent in the grapes, though in hot climates (and where it's legal) winemakers may add some tartaric or citric acid to balance the sugar in ultraripe fruit. Acidity can also be manipulated through a process called malolactic fermentation (this is actually a bacterial activity, not a true fermentation). The process takes place after alcoholic fermentation, almost always in red wines and selectively in whites, according to the winemaker's vision of the wine. It transforms rather harsh malic acid (the kind found in green apples) to softer, rounder lactic acid (the kind found in milk), yielding softer wines that, especially in whites, often show marked buttery or creamy flavors.

Tannins are elements extracted primarily from grape skins (and so found mostly in red wines), but which can derive from stems or seeds, and also from oak, especially new oak barrels. They're perceived as an astringent feeling. Young red wines meant for long aging are pumped full of tannins, by extending the maceration period or otherwise enhancing their extraction, because tannins act as a preservative and their chemical evolution toward softer, silkier textures is part of the maturation of great wines.

When drinking a Cabernet, perhaps, in your mouth you may note a marked astringency, plenty of fruit and very little tartness. When you swallow, there's a warm feeling in the back of your throat followed by a long aftertaste. You can reasonably assume that the wine is made from ripe grapes, possibly grown in a warm climate, and that the winemaker emphasized extraction to produce a long-lived wine. If the wine is too alcoholic and lacking in acidity, the grapes may have gotten too ripe before they were picked. If the tannins are too harsh, the winemaker may have left the juice on the skins for too long, aiming to make a super-wine but winding up with a bodybuilder, impressive in youth but unlikely to maintain its form.

Don't stop concentrating when you swallow, though. The finish—the taste that lingers for seconds, even minutes, when the wine is gone—is the wine's farewell. If it's short, the wine is simple and probably meant for early drinking. The longer it is, no matter what its age, the better the chances you have a winner.

With age the tannins soften and the wine, which may be a collection of impressive but disparate impressions in its youth, will become more harmonious and complex. One of the most important and least certain judgments a wine taster makes is when a wine will reach its peak, achieve a point when all its elements come into alignment, creating a seamless web of color, aroma and flavor. One reason to invest in a wine by the case is to follow its evolution through the years. This maximizes your chances of catching the wine at its best.

Text from www.winespectator.com.