Why swish? While it was originally thought that certain regions on the tongue detected specific flavors, we now know this is not true.

The front and back of the tongue contain the taste buds and rather than specializing in a particular taste sensation, all taste buds are capable of detecting sweet, sour, bitter and salty flavors, although there may be some slight differences in sensitivity. So that you get the most out of your taste buds, when wine tasting, swish the wine around your mouth, which will allow all of your taste buds (and your sense of smell) to participate in the detection of the finer flavors of the wine.

Smell and Taste
Have you ever tried desperately to detect flavor from a food or beverage when you had a terrible cold? You probably tasted very little, if anything at all. Research indicates that 70 to 75% of what we taste is actually due to our sense of smell. Specialized "aroma" nerves in the nose are necessary to identify tastes more subtle than sweet, sour, bitter and salty. Smell and taste go hand-in-hand when wine tasting . . . without your sense of smell you would be unable to detect the delicate flavors of chocolate, herbs or smoke in your wine.

Wine Tasting Techniques

Wine tasting is not just like an art; it is an art. While wine tasting can be subjective in nature, wine connoisseurs follow some general  "guidelines" when judging a wine. It's very easy to learn the techniques of wine tasting, and if you already enjoy wine, learning the nuances will simultaneously increase the pleasure you derive from tasting.

The three steps in wine tasting are: Look, Smell, and Taste.
 
Look
You can tell much about a wine simply by studying its appearance. The wine should be poured into a clear glass and held in front of a white background (a tablecloth or piece of paper will serve nicely) so that you can examine the color.

The color of wine varies tremendously, even within the same type of wine. For example, white wines are not actually white; they range from green to yellow to brown. More color in a white wine usually indicates more flavor and age, although a brown wine may have gone bad. Where as time improves many red wines, it ruins most white wines. Red wines are not just red; they range from a pale red to a deep brown red, usually becoming lighter in color as they age.

Rim color: You can guess the age of a red wine by observing its "rim." Tilt the glass

Wine Definitions: Basic

Acidity: Describes a tart or sour taste in the mouth when total acidity of the wine is high. "Tart" and "twangy" are two descriptors for acidity.
Aftertaste: The taste or flavors that linger in the mouth after the wine is tasted, spit or swallowed. May be "harsh," "hot," "soft," "lingering," "short," "smooth," or nonexistent. See also 'Finish.'
Aroma: Usually refers to the particular smell of the grape variety, i.e., "appley," "raisiny," "fresh" or "tired."
Body: The weight of wine in your mouth; commonly expressed as full-bodied, medium-bodied or medium-weight, or light-bodied.
Bouquet: A tasting term used to describe the smell of the wine as it matures in the bottle.
Finish: The taste that remains in the mouth after swallowing. A long finish indicates a wine of good quality.
Legs: The viscous droplets that form and ease down the sides of the glass when the wine is swirled.
Length: The amount of time the sensations of taste and aroma persist after swallowing.
Mouthfeel: How a wine feels in the mouth and against the tongue.
Nose: See 'Aroma'
Palate: The feel and taste of wine in the mouth.
Quaffer: A wine to drink (not sip).

Varietal:  A wine make from a single grape source, such as Chardonnay, Cabernet, Merlot, etc.

Wine Definitions: Character

Acrid: Describes a wine with overly pronounced acidity. This is often apparent in cheap red wines.
Assertive: Upfront, forward.
Attractive: A lighter style, fresh, easy to drink wine.
Balanced: Indicates that the fruit, acid, wood flavors are in the right proportion. A wine is well balanced when none of those characteristics dominates. Wine not in balance may be "acidic," "cloying," "flat" or "harsh."
Big: A wine that is full-bodied, rich and slightly alcoholic tasting.
Character: A wine with top-notch distinguishing qualities.
Crisp: Denotes a fresh, young, wine with good acidity.
Cutting Edge: Stylistic, hip.
Closed: Describes wines that are concentrated and have character, but are shy in aroma or flavor.
Complete: A full-bodied wine rich in extracts with a pronounced finish.
Complex: Describes a wine that combines all flavor and taste components in almost miraculous harmony.
Delicate: Used to describe light- to medium-weight wines with good flavors.
Dense: Describes a wine that has concentrated aromas on the nose and palate, desirable in young wines.
Depth: Describes the complexity and concentration of flavors in a wine. Generally refers to a quality wine with subtle layers of flavor that go "deep." Opposite of 'Shallow.'
Developed: Refers to the maturity of a wine.
Elegant: Describes a wine of grace, balance and beauty.
Empty: Flavorless and uninteresting.
Fading: Describes a wine that is losing color, fruit or flavor, usually as a result of age.
Flabby: Lacking acidity on the palate.
Flat: Having low acidity; the next stage after flabby; or refers to a sparkling wine that has lost its bubbles.
Full-Bodied: Fills the mouth. Opposite of 'thin-bodied.'
Graceful: Describes a wine that is subtly harmonious and pleasing.
Neutral: Describes a wine without outstanding characteristics, good or bad.
Pedestrian: Plain.
Potent: Describes a strong, intense, powerful wine.
Robust: Describes a full-bodied, intense and vigorous wine; possibly inflated.
Round: Describes a well-balanced wine in fruit, tannins and body.
Seductive: A wine that is appealing.
Short: Describes a wine that does not remain on the palate after swallowing.
Simple: Describes a wine with few characteristics that follow the initial impression. Not necessarily unfavorable; often describes an inexpensive, young wine.
Soft: Describes a wine with low acid/tannin, or alcohol content with little impact on the palate.
Supple: Describes a wine with well-balanced tannins and fruit characteristics.
Thin: Lacking body and depth.

Wine Definitions: Taste

Barnyardy: Smell of farm animals. Negative.
Bite: A marked degree of acidity or tannin. An acid grip in the finish should be more like a zestful tang and is tolerable only in a rich, full-bodied wine.
Bitter: One of the four basic tastes. Considered a fault if the bitterness dominates the flavor or aftertaste. A trace in sweet wines may complement the flavors. In young red wines it can be a warning signal, as bitterness doesn't always dissipate with age. A fine, mature wine should not be bitter on the palate.
Buttery: It refers to both flavor and texture or mouthfeel.
Chewy: Describes rich, heavy, tannic wines that are full-bodied.
Corked: The wine tastes of cork, it is unpleasant to smell and taste, slightly musty.
Dirty: Covers any and all foul, rank, off-putting smells that can occur in a wine, including those caused by bad barrels or corks. This is usually a sign of poor winemaking.
Earthy: Describes a wine that tastes of soil, most common in red wines. Can be used both positively (pleasant, clean quality adding complexity to aroma and flavor) and negatively (barnyardy character bordering on dirtiness).
Flinty: Describe the aroma or taste of some white wines; like the odor of flint striking steel.
Fruity: Describes any quality referring to the body and richness of a wine, i.e., "appley," "berrylike" or "herbaceous." Usually implies a little extra sweetness.
Grapey: Describes simple flavors and aromas associated with fresh table grapes.
Green: Tasting of un-ripe fruit. Not necessarily a bad thing, especially in a Riesling.
Heady: Used to describe the smell of a wine high in alcohol.
Herbaceous: The taste and smell of herbs.
Murky: Lacking brightness, turbid or swampy.
Musty: Having a moldy smell.
Oaky: Describes the aroma and taste of oak.
Oxidized: Describes stale or 'off' wines.
Peppery: Describes the taste of pepper in a wine; sharper than 'Spicy.'
Perfumed: Refers to a delicate bouquet.
Smoky: Describes a subtle wood-smoke aroma.
Spicy: Describes the presence of spice flavors such as anise, cinnamon, cloves, mint and pepper, often present in complex wines.
Sweet: One of the four basic tastes. Describes the presence of residual sugar and/or glycerine.
Tannin: Describes a dry sensation, with flavors of leather and tea.
Tart: Sharp-tasting because of acidity. See also 'Acidic.'
Toasty: Describe a hint of the wooden barrel. Usually associated with dry white wines.
Velvety: Having rich flavor and a silky texture.
Zesty: A wine that's invigorating.