Chemical substances from the large group of phenols (Polyhydroxyphenols), which are found in the bark of many trees, shrubs and shrubs as well as in the peel of fruit such as in the grapes especially from red wine varieties. They ultimately serve the plants as a defense against herbivores or predators and also as protection against microorganisms, Tannins can be a variety of virus inactivate and therefore have an antitoxic effect. They also have a very strong tanning effect, which is why they have been used for the production of leather for thousands of years. For this reason, they are often colloquially called tannins referred to, but this term is rather negative or derogatory compared to tannins.
All tannins are odorless, easily oxidized and in water and ethanol (Alcohol) soluble. You react with proteins (Proteins). That is why protein opacities Rarely in red wines, because the insoluble tannin-protein compounds fail and already with the lees be removed. Tannins are an essential characteristic of everything red wines and to a much lesser extent also from White wines, They are characteristic of that astringent (mouth-contracting) effect responsible, which incidentally not to the taste, but to the trigeminal Sensory impressions count. The bitter Taste, however, comes mainly from the tannin-like catechin,
The tannin content in Wine is mainly from the winemaking ( fermentation and expansion ) as well as from the vine dependent. The tannin-rich varieties include, among others Blaufränkisch. Cabernet Sauvignon. Cot (Malbec) Mandilaria. Monastrell (Mourvèdre) Nebbiolo. Petit Verdot. Sangiovese. Syrah and Tannat, Low tannin varieties or those with "soft tannins" Carmenère. Cinsault. Gamay. Merlot. Pinot Noir. St. Laurent. schiava (Vernatsch, Trollinger) and Zweigelt, The longer the duration of red wines maceration the more the mash is pressed, the more tannins and anthocyanins (Dyes) get through extraction in the wine.
The white tannin content is 0.3 g / l for white wines, but up to 2.5 g / l for red wines (see a list of all wine ingredients below total extract ). For an objective measurability, the Tanninindex developed. The low proportion in white wines is mainly due to the type of winemaking, because here at the fermentation usually no combs and grape seeds are involved. Only one Maceration a higher tannin content is also achieved in white wines. Over time, the tannin content in the wine softens naturally, because of the polymerization larger molecules form than depot be canceled and to bottle bottom decline.
A distinction is made between two groups according to the origin of the tannins. The “grape-bearing tannins” come from the seeds, combs (black horse, stems) and the skins of grapes; only a very small part comes from the pulp. They are also called flavonoid Tannins, condensed tannins or proanthocyanidins. These in turn consist of prodelphinidines (only in bowls and stems) and procyanidins (also in grape seeds). These are the main ingredient in wine. The second group of "wood-borne tannins" with a significantly lower proportion comes from the wood of one barrel aging respectively. Barrique, These are also known as hydrolyzable tannins or ellag tannins. By oxidation and sour hydrolysis decompose ellagic acid and gallic acid, These tannins promote the polymerization of the anthocyanins to more intensely colored color pigments. They make a positive contribution to color stabilization and aging in red wine.
Since the mid-1980s, various techniques have been used in red wine production to improve the taste towards "mild" on the one hand and the positive effect of the tannins on the other aging respectively. bottle aging on texture and durability to improve. This is especially the case with Barrique the proportion of new barrels, the type of oak and the extent of toasting, Regulate the tannin content by beautiful, as well as a targeted, dosed oxygen supply by means of micro-oxygenation, The use of oenological tannins (especially wooden ones), which are used individually in winemaking: in the maceration, after this BSA, before the barrel aging or before bottling, The use, which is not without controversy, has a taste-changing effect. There are two negative terms for the tannin taste green tannins and tannin to loose, See also under wine address and wine review,
oenological tannin: By Simon A. Eugster - Own work, CC BY 3.0 , Link
Barrel barrel: By Gerard Prins - Own work, CC BY-SA 3.0 , Link
Grape varieties: Ursula Brühl, Doris Schneider, Julius Kühn-Institut (JKI)