Must

Must is the freshly pressed juice of grapes, often used in the production of wine. It 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. 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 must is measured in degrees Brix, which refers to the percentage of sugar in the liquid. The ideal level of sugars in the must is 24 to 27 Brix. The pH of the must is typically between 3.0 and 3.7; this measurement is important in determining the finished acidity of the wine.

Winemaking

In winemaking, must is fermented by yeast to produce alcohol. The process of fermentation continues until all of the sugar is converted into alcohol and dry wine is produced. To stop fermentation at a desired sweetness level, winemakers can add sulfur dioxide to the must to inhibit further yeast activity.

Culinary uses

In cooking, must is often used as a sweetener and condiment. In Italy, must is boiled to produce a thick syrup known as saba which is used as a sweetener or condiment. In ancient Rome, must was reduced and mixed with ground mustard seeds to make a condiment known as mustum ardens, or "burning must".

See also

• Grape juice
• Winemaking
• Viticulture
• Oenology