Punch-Down

Pummeled grapes: the floating cap of skins and stems atop the fermenting wine is submerged again in a rotating process. This deepens the flavor and color, enhances the tannins. As the sugar converts to carbon dioxide, again the solids return to the surface, and again they are punched down into the liquid, until finally the skins rest along the bottom. It's essential, some say, to the creation of a full-bodied wine.