Wine tannin will improve the flavor of a dull wine. Tannin can be used with white wines that have not been exposed to oak to add astringency. Wine tannin can also add an earthy flavor to red wines. Use in conjunction with gelatin or is in glass for later fining as well.
Wine tannin can add an earthy flavor to red wines
Wine Tannin will improve the flavor of a dull wine
Tannin can be used with white wines that have not been exposed to oak to add astringency