Grape phylloxera

Grape must is the freshly crushed grape juice that contains the skins, seeds, and stems of the fruit. The solid portion of the must is called pomace and typically makes up 7–23% of the total weight of the must. Making must is the first step in winemaking. Because of its high glucose content, typically between 10 and 15%, must is also used as a sweetener in a variety of cuisines. However, unlike commercially sold grape juice, which is filtered and pasteurized, must is thick with particulate matter, opaque, and comes in various shades of brown and purple.

Composition

The sugar content of grape must is measured in degrees Brix. In France, the measure is degrees Baumé. In Italy, the measure is degrees Brix and sometimes degrees Plato (especially for beer). Freshly crushed and destemmed grapes are put into a vat or tank and then the fermentation process begins. The must is then pressed, and the juice is moved to a tank where it is left to ferment. The pomace, or the solid portion of the must, of white grapes is quickly removed from the juice before it ferments, to keep the wine from becoming too tannic. After the primary fermentation, further stages of fermentation may take place. Once the fermentation is complete, the must can be removed from the wine.

Uses

In winemaking, grape must is the primary raw material. For the production of vinegar, must is used as the starting material. It is also used in the production of non-alcoholic drinks and as a sweetener in certain foods and drinks. In Italy, must is used in the bakery industry for the production of certain types of bread and cakes. It is also used in the production of the dessert wine Vin Santo.

Health benefits

Grape must is rich in antioxidants and polyphenols, which have been linked to a variety of health benefits, including reducing the risk of heart disease, improving brain health, and slowing down the aging process. It is also a good source of vitamins and minerals, including potassium, calcium, and iron.

See also

• Winemaking
• Vinegar
• Antioxidants
• Polyphenols