Tannin for home winemaking
Dosage is 1/4 teaspoon per 5 litres (1 gallon) of wine or as per your recipe.
Tannin will add "bite", structure and depth of flavour to your wine whilst enhancing your wine's keeping ability.
Add the tannin at the same time as your sugar and yeast (unless your recipe states otherwise).
This is the product that professional wineries use.