A reassessment of sorghum for lager-beer brewing

The out-of-steep moisture of sorghum is lower than expected (33-36%), but is adequate for enzymic modification of endosperm substrates of sorghum, producing sufficient amylolytic enzymes for brewing lager-type beers. The 65 °C standard mashing procedure limited extract recovery from sorghum malt due to inadequate gelatinization of sorghum starch. The 65 °C mashing was, however, optimal for nitrogen solubilization and hydrolysis of the soluble proteins, yielding high levels of peptides and amino acids. In order to obtain optimal extract yield containing sufficient mash-tun sugar/protein extracts from sorghum malt, a controlled temperature mashing regime would be required. A high germination temperature of 30 °C is required for optimal sorghum malt qualities, even though excessively high respiratory and carbohydrate malting loss occurred at 30 °C germination. This notwithstanding, sorghum germinated at 30 °C contained higher nitrogen materials in the embryo than in the roots. Also the presence of minerals in the embryo of sorghum may, in part, influence the enzyme-producing potentials of the embryo of sorghum.