To saccharify means to convert to sugar. In whisky distilling it refers to the process which takes place during the malting and mash-tun stages by which enzymes in the malt, referred to as diastase, turn the starch in the cereals into sugar ready for the fermenting action of the yeast. When conditions of temperature and moisture favour germination, the embryo and associated parts of the barley grain secrete a mixture of enzymes commonly known as diastase. These act to modify and make soluble the starch in the barley, thus preparing it for conversion at a later stage to maltose. Wort is the liquid drawn off the mash-tun in which the malted and unmalted cereals have been mashed with warm water.
Wort contains all the sugars of the malt and certain secondary constituents.
After cooling, it is passed to the fermenting vats. In some cases, Grain distilleries do not separate off wort, passing the complete mash to the fermentation vessels. The wort or mash technically becomes wash as soon as yeast is added to start fermentation. However, the term is usually used to refer to the liquid at the end of the fermentation. The spirit is driven off from the fermented liquid as a vapour and then condensed back to a liquid.