Maceration is the
winemaking process where the
phenolic materials of the grape—
tannins, coloring agents (
anthocyanins) and flavor compounds—are leached from the grape skins, seeds and stems into the
must. To macerate is to soften by soaking, and maceration is the process by which the red wine receives its red color, since 99% of all grape juice (with the exceptions of
teinturiers) is clear-grayish in color. In the production of white wines, maceration is either actively avoided or allowed in very limited manner in the form of a short amount of skin contact with the juice prior to
pressing. This is more common in the production of
varietals with less natural flavor and body structure like
Sauvignon blanc and
Sémillon. For
Rosé, red wines grapes are allowed some maceration between the skins and must, but not to the extent of red wine production.