Preparation of a low carbohydrate beer by mashing at high temperature withglucoamylase

A malt grist, supplemented with glucoamylase (1,4-alpha -D-glucan glucohydr olase, EC 3.2.1.3), was mashed isothermally at 70 degreesC to produce wort with a real fermentability of over 87% and beer with a residual carbohydrat e contents of less that 0.75% w/v at an original gravity of 42 degreesS. Th e effects of varying mash pH, calcium content, glucoamylase addition rate a nd mash conversion time were investigated. The process was effective even w ith undermodified malt. Pilot scale brewing trials showed no adverse effect on beer foam quality when th glucoamylase preparation had a specified rang e of protease side-activity. The process has the advantage of ensuring gluc oamylase inactivation during wort boiling while being shorter than the alte rnative of enzyme treatment of wort prior to boiling.