Grape must is freshly crushed grape juice, including the skins, seeds, and pulp, before fermentation turns it into wine. It is the raw material winemakers start from, carrying all the natural sugars, acids, and tannins present in the grape before any yeast acts on it.
Red grape must is fermented in contact with the skins and seeds to extract color and tannin, while white grape must is pressed and clarified before fermentation for a lighter result.
Beyond wine, must can be reduced to a syrup-like consistency and used as a sweetener or flavoring agent in desserts, sauces, and marinades; it can also be distilled into grape brandy or fermented into vinegar. Grape must is distinct from verjuice, the tart juice of unripe grapes used as an acidic seasoning.