firm tannins, silky tannins, racy tannins....?

[Bucko]

Tannins ripen just like other components of the grape. Grapes picked too green give green, harsh, chewy tannins that are unpleasant. Ripe tannins that are overextracted are also chewy and harsh. The art is balancing ripeness with extraction. There are also other techniques used to soften tannins, e.g. microoxygenation for one (I think).

Racy tannins is someone looking for a new word for their proise.