English professional term

[Innkeeper]

Hi Valeriy, and welcome to the Wine Borad. "'Must' is the name used by wine-makers for the thick liquid that is a mixture of grape juice, grape skins, seed, and pulp and that comes from the crusher-destemmer that smashes grapes at the start of the winemaking process."-Janis Robinson.

If the juice is separarted from the other matter and shipped before fermentation, it is simply refered to as juice or grape juice.