Which compounds found in grape skins and seeds provide red wine with its characteristic astringency and puckering sensation?

Tannins

Tannins are polyphenols that act as a natural defense mechanism in plants and serve as a preservative that allows red wines to age for decades. They create a drying sensation by binding to proteins in human saliva, which is why high-tannin wines pair exceptionally well with protein-rich foods like steak.