Your tongue can taste only a few flavors in wine but the complete impression of the wine is lot more complex than the four basic flavors of sweet, salty, sour and bitter. It is the aroma and the contents of wine that add to the complete mouth feel. The overall taste of wine is built by this interaction of the contents, aroma, flavors and sensations.

Sugar

Grapes contain various types of sugars in large quantities. The yeast breaks down and converts these sugars into alcohol. Many sugars are left behind, in the finished wines, depending on the yeast and the grape. The sweetness can be detected by the tip of the tongue. The sensation of sweetness can be largely influenced by other wine flavors.

Also, the temperature at which the wine is served can affect the sweetness perception because the wine served chilled is perceived to be less sweet than a warmer wine.

Tannin

Tannin is an important content of wine, especially for aging of red wines. They are found on the grape skins, pips and stalks and are natural preservatives. Wine also receives tannin form the oak barrels in which they are stored. If the tannin content is in the right level they give the wine a good mouth feel and also softens the other flavors in the wine. The tannins breakdown in the bottles over many years to give much softer versions that is desired. The Bordeaux wines are famous for being enjoyed after years of aging, as they tend to have strong tannins when they are young.

Alcohol

Without alcohol, the wine just doesn’t exist. The level of alcohol depends on the amount of sugar in the grape. The alcohol in the wine is a byproduct of the extraction of energy from the sugar by yeast. Though our tongue cannot taste alcohol, it has a significant effect on the mouth. If there is no alcohol content in wine, it will be a very sweet drink as the sugar will be unbalanced. It is the most important factor of alcohol, apart from the exhilaration!

Acidity

All fruits, be it mango, orange, apple or grape, require acidity. It gives the fruit a flavor and refreshing sensation without which the fruits will be cloy and overly sweet. As in fruits acidity is also very important in wines, but in right quantity, to give that perfect refreshing flavor. If the wine is too acidic, it will be sharp and undrinkable and if it has too less acidity the wine will be cloy and dull. You can detect the acidity by the sharp sensation of the wine around the edges of the tongue.

Oak

The oak flavor is neither found in the wines or the grapes. Many wines are aged in oak barrels, some even fermented in them. The wines extract the oak flavor from these barrels. The flavors can vary from vanilla, butter, caramel, toffee or butterscotch. The characteristic of the oak flavor can depend on the length of time the wine is stored or fermented, the acidity content of the wine, how much oak is used, how many times the oak has been reused, etc.