LIMIT DEXTRINASE: 1. ACTION OF LIMIT DEXTRINASE IN DISTILLING

Abstract

Fermentation of unboiled wort by industrial yeasts leads to the formation of much more alcohol than is obtained when boiled worts are fermented. This is true even of brewery malts of D.P. 20–40 when mashed at 150° F. for 2 hr. It is shown that this extra production of alcohol cannot be brought about by malt α- and β-amylases acting in conjunction with the yeast, and that the saccharification of about one-fifth of the starch requires the presence of the additional enzyme, limit dextrinase. This survives mashing and is able to function slowly after the primary fermentation of unboiled wort is complete. Its existence in malt, even distiller's and diastatic malt, was hitherto not securely established, since results reported in the literature could be accounted for on the basis of the activities of α- and β-amylases. Its presence has been demonstrated in a malt of D.P. 19°.