Tannin is sometimes hard to define. Some red wine drinkers love it and others hate tannin. What exactly is tannin?
Tannins is phenolic compounds extracted from the skins, stems, and seeds of grapes. Tannin play an important part in wine production. They also contribute to the taste of wine. When many wine drinkers think of red wine they think of tannin. The longer the wine stays in contact with the skins, stems, and seeds the more tannin absorbed.
It is hard to describe the exact taste of tannin. It can be described more as a sensation than a flavor. It is the slight clenching feeling at the back of your jaw when you drink a red wine with noticable tannin. It is what creates that dry feeling in your mouth when you drink a great dry wine. Wine without any tannin is often flat and insipid. Bite a grape seed and you will understand the extreme tannic experience.
Tannin is an astringent that occurs naturally in grapes. Tannin acts as a ntural fining agent. Proteins combine with tannin to form heavy solids that sink to the bottom of the barrel or bottle. This process is called flocculation and is a natural clearing process in wine. Wine that is cloudy is often in need of tannin. Since tannin naturally occurs in black tea many novice home winemakers have made the mistake of using black tea to add tannin. Please don't do this, the flavor of the tea will remain in the wine.
Tannin serves an important function in the preservation of wine. The tannin is what allows a good red to develop a great taste over 5-10 years. As you know from biting the grape seed too much tannin is not a good thing. Many of us have had the painful experience of drinking a red wine that has caused our mouths to pucker and our jaws to clench. The flavor of the fruit is lost. On the other had without enough tannin the wine may taste more like fruit punch than a good red wine.
Tannin is also naturally present in oak. The term tannin comes from the Celtic word for oak. Oak barrels pass on their own tannin to wine as it ages, adding to the sublte flavors of the wine.
