Effect of an agent (lat. Astringent), through the contents of which skin tissue or mucous membranes are contracted (Latin adstringere = contract). The astringent goes with the proteins of the skin and mucous membranes compounds that form a protective wall (membrane). In medicine, such remedies as alum are used to stop bleeding. In the context of a wine description, astringent means a sensory complex that expresses itself through a rough, or the oral mucous membrane drying out or "mouth contracting" effect. This is due to high levels of phenols ( tannins ), which are particularly prevalent in the woody parts of fruits such as stalks, pods, shells and kernels. These are z. Almonds, chestnuts, green nuts, artichokes and anthocyan (Dye-rich) varieties, The latter, like the one shown in the picture, usually have a dark (black) berry color.
The astringent substances cause a contraction of the organic tissue in the oral cavity, prevent the saliva secretion and thereby cause a roughening effect on the mucous membranes. But it is not (although it seems) no olfactory or Taste sensation but a tactile or trigeminal Irritation (affecting the sense of touch) on the mucous membranes of the cheeks insides and the nasal cavity and may not with bitter or angry be confused. The sensation is also from the wine temperature dependent and is amplified at low temperature. The bandwidth can vary from weak to just positive intrusive to the already negative aggressive rich.
Astringency is usually a feature of young people red wines, The impression can be felt during the bottle aging or in the course of aging process significantly mitigate and by the precipitate the causative substances even disappear completely. The astringent effect is in most cases positive for low-acid red wines and can also stimulate the appetite. at White wines however, this is usually an undesirable negative property and is considered phenolic designated. See also below wine address,
Pictures: Ursula Bruehl, Doris Schneider, Julius Kühn Institute (JKI)