Vacuum wort – natural grape juice (not fermented), evaporated under vacuum to a viscous liquid.

The use of low pressure allows to avoid high temperatures and to preserve the original composition of the raw material. However, a significant proportion of aromatic compounds is inevitably lost.

Such a concentrate with high content of natural grape sugars (not less than 65 mass%) and other constituents of grape must, used in the production of cheap wine for sweetening (and sometimes for coloring) low-grade wine without resorting to artificial additives.