Tannic acid

Tannic acid technically belong to the so-called 'gallotannins', a class of 'hydrolysable tannins'. Tannic acid is the rancid and bitter element in red wines and comes from the grape skin, stone and stems, as well as by aging in oak casks. The word 'tannic acid' does not sound particularly inviting, but fortunately, it softens with age and becomes an indispensable element of a wine storage potential. A white wine does not contain tannins, as there is only a short-term or no contact with the grape skins during fermentation.