Wine has a unique taste and this article will explain the sources of wine's unique taste.

We drink wine to stimulate our taste buds, alter our brains (via alcohol), and/or quench our thirst. Stimulating the taste buds via foods and beverages is a significant part of the human experience. Human taste is comprised of four basic components: sweetness, saltiness, acidity, and bitterness. Of major importance in both the production and enjoyment of wine is its natural acidity, the component against which the other taste components are balanced.

In particular, the precise balance of acidity and sweetness - from natural sugars, “fruity” flavors, and/or alcohol - is the key factor that makes wine pleasant tasting. Too much acidity makes a wine taste unpleasantly sharp, whereas a lack of sufficient acidity results in an uninteresting wine that is neither clean tasting nor thirst quenching. Flavors are detected by different taste buds in your mouth that individually perceive one of the four components of taste. The areas most sensitive to sweetness is on the tip of the tongue, and the sensation is immediate.

Taste buds that react to saltiness are on the sides of the tongue, with the acidity-tasted buds located toward the middle. The taste buds that detect bitterness are located at the back of the tongue, and are therefore the last to get involved with the food or beverage in your mouth. This is why people often note a bitter aftertaste when eating and drinking certain foods. When tasting wine, a little stimulation of the bitterness-sensing taste buds is pleasant.

Of course, what constitutes “too much” varies from day to day for any individual. People’s mouth vary from day to day depending on what they ate today or yesterday, their physical health, the time of day, etc. If you burn your mouth on a hot slice of pizza, the acidity of any wine is not going to feel good.

There are several different acids that occur naturally in wine – tartaric, malic, lactic, citric, and acetic acids, Therefore, when we speak of acidity in wines, we really mean the “acidity profile”; the total and often complex acidic impression of the wine on the palate. The acidity profile and its corresponding balance of complementary components are of primary importance in white wines.

Red and white wines with excessive acidity taste harsh, especially without food. Wines with too little acidity do not have an interesting taste and their flavor does not linger in the mouth very long. Although red wine is typically no less acidic than white wine, the acidity profile is often less apparent in reds because red wines usually display a more complex array of flavor components than do white wines.

The difference is in the skins – white wine grapes skins are removed and discarded early in the winemaking process, whereas red wine grape skins are generally kept in the fermenting vats long enough to give red wine its color, complex flavors, and tannin.

Tannin is an important component of red wine. Have you ever bitten into a grape seed? That dry, bitter taste is tannin. In moderate amounts tannin gives red wine an added flavor dimension as well as a natural preservative. Great red wines are often quite tannic in their youth; with aging the tannin softens and lends complexity to the mature red wine. In most red wines, tannin adds a pleasant, slightly bitter flavor that is best balanced by rich fruit flavors. If you find it difficult to imagine bitterness as pleasant, think of expensive dark chocolate or rich espresso coffee, bitterness is certainly an important part of their flavors.

Red wine with too much tannin is bitter and unpleasant, and its fruit flavors may be hidden beneath the tannins. The correct amount of tannin does not mask other flavors, but instead gives the wine a little “grip” in the mouth and seems to hold all the flavors together. A low measure of tannin makes simple, fruity red wine more suitable for quaffing than sipping.

Generally speaking, a high level of tannin is an indication of a long shelf life, since tannin is a natural preservative.