Diastase

Diastase (from the Greek diistemi, I separate). a name applied by Payen and Persoz in 1833 to a nitrogenous ferment present in germinating seeds and perhaps in the cells of other parts of plants. It has never been satisfactorily separated or analysed; but its discoverers stated that it formed 1/500th of the weight of malt and that it is capable of bringing about, by an action which cannot be said to be understood, the transformation of 2,000 times its own weight of starch into sugar. Other albuminoids are now known to produce the same change, though less actively. Their action is analogous to that of the ptyalin in the saliva of the higher animals. It is the presence of diastase that enables the brewer to use four parts of raw grain to one of malt in the process of mashing.