Het is een smaak sensatie in de mond, veroorzaakt door tanine. Ik weet niet hoe wijnkenners het exact zouden omschrijven, maar 'tanine nasmaak' dekt op zich wel de lading. Zie onderstaande tekst:

In the mouth, wine’s sensation on the tip of the tongue comes from the fruitiness found in grape juice. The grape skins provide a feeling found more mid-palate and in the back of the mouth. A third and most important mouth sensation is a slight ache or pressure point in the lower, back jaw area. This is the tannin, the backbone of red wine.
Strong tannins can give that dry-cottony mouth feeling. This dryness comes from a grape’s thick leathery skins, their woody stems and seeds, also known as pips. Extra-dry wines are more prevalent in Italian red wines and American cabernet sauvignons than pinot noirs.

afkomstig van onderstaande link.