Tannins?

[Thomas]

tandkvd, in defense of ww, I think what he was trying to tell you is that your question, tiny as it seems, is a large one. The answer you have been given, accurate as it is, represents a small portion of the tannin subject. While tannic acid is part of the make-up of wine by way of the grapes, there are other ways for it to be introduced in wine. And its effect is not just as simple as to induce proper aging, although that is among its major influences on wine. As for fining tannins away--that is a dangerously easy-sounding solution to a highly tannic wine.