Tannin softening

Tannin softening is the process by which the tannic structure of a red wine mellows over the course of bottle ageing. Tannins, at first firm and astringent in a young wine, bind together into long chains that eventually precipitate as sediment. The sensation on the palate then gains in velvet and integration. This phenomenon explains why a powerful wine becomes more harmonious after several years in the cellar.