Definition - What does Must mean?
In the context of red wine making, making must is one of the first steps in winemaking and is the soup of pressed grapes that includes the fresh juice, the skins, seeds and stems. Must is a thick opaque mixture that can vary in color from deep purple to light shades of brown depending on the grapes being pressed. How the winemaker manages the must will determine many of the final characteristics of the wine being made including; color, acidity, and tannin levels.
WineFrog explains Must
Must is the first step in red wine making after the grapes have been harvested from the vine. The must contains the grape juice and pomace, pomace is the solids from the skins, seeds and stems. Grapes are pressed to release the juice, and as the grapes are pressed whole, this soupy mixture of skins, seeds and stems is called, must. The term is derived from from the Latin, vinum mustum, which means young wine.
After harvest, the grapes are pressed to extract the juice, and the must is the fresh juice before it is strained to remove the seeds, skins and stems. Vintners can press single grape varieties or blends, depending on the style or type of wine they are making. How long the must sits will determine flavor and color characteristics of the wine. Initial fermentation can begin in the must from the yeast present on the skins but is also determined by how long the must is left to sit.