Vacuum-Thickened Must

(also vacuum-thickened juice or grape honey), must thickened in a vacuum apparatus and containing 60-80 percent sugars (mainly glucose and fructose), as well as organic acids (mainly tartaric and malic) and mineral and nitrogenous substances. The first vacuum-thickened must was prepared in steam kettles or directly over a fire. Must thickened in this way was known as bekmes. Thickened must is a valuable product used mainly in wine-making in blending sweet wines. As a food, thickened must is a natural source of easily assimilated sugars. It keeps well when at high concentrations of sugars; at low concentrations it must be stored at low temperatures.