To most people, tasting wine means taking a sip and swallowing it immediately. This is a common misconception. Tasting is something you do with your taste buds.
When you sip and swallow immediately, you bypass a lot of important taste buds. By tasting properly and allowing the wine to reach all of your taste buds, your nose is also able to help your brain pull together specific pictures which accurately reflect the different aspects of a wine's taste.
Here are some of the tastes of wine:
Sweetness: This is tasted on the tip of the tongue. If there is any sweetness in a wine, you'll taste it right away since the tip of your tongue is highly sensitive.
Fruit and Varietal Characteristics: These are tasted in the middle of the tongue after the sweetness has been established.
Acidity: Tasted at the sides of the tongue and on the insides of the cheeks -- acidity is more apparent in white wines than red wines.
Tannin: This is also tasted in the middle of the tongue. Tannin frequently is much more prominent in red wines or wood-aged white wines. It can "dry" the palate to excess when too much tannin is present. Tannin tends to feel astringent on the palate. We like to call it the "wool sweaters on the tongue." Tannins are frequently apparent in bananas, and walnuts and teas.
Finish: The finish, or aftertaste, is the overall taste that lingers after you have swallowed or spit the wine. How long does the taste linger? Usually a sign of a high quality wine is a long, pleasing aftertaste lasting from 15 to 20 seconds after you've swallowed the wine.
We recommend having a cracker or two (unsalted), or another bland substitute, in order to cleanse your palate between tastes. The taste of one wine can influence that of another.
Keep in mind too, that your palate can be influenced by seemingly unrelated things such as what you ate for lunch, or what you smell cooking nearby, etc.