Today in 1982, US Patent 4355047 A was issued, an invention of William F. Line, Vinod K. Chaudhary, Etzer Chicoye, and Robert J. Mizerak, assigned to Miller Brewing Company, for his “Method of Preparing a Low Calorie Beer.” Here’s the Abstract:
Low calorie beer is prepared by introducing into the brewing process a debranching enzyme (pullulanase) obtained from rice, a traditional brewing material. The debranching enzyme reduces the real extract of the beer by cleaving alpha 1,6 linkages of unfermentable limit dextrins to form alpha 1,4 dextrins which can be converted by alpha 1,4 carbohydrates to sugars that can be fermented by brewer’s yeast. The enzyme may be introduced into the brewing process by adding rice or the enzyme extracted from rice to the mash or to the wort before or during fermentation. The debranching enzyme may be obtained from polished dry milled rice by extraction with an aqueous buffer solution. When malted rice is used as the enzyme source a particularly useful mixture of the debranching enzyme and alpha 1,4 carbohydrates is obtained.