EFFECT OF ALKALINE STEEPING ON WATER-UPTAKE AND MALT QUALITY IN SORGHUM

Condensed tannin-free and high-tannin sorghum grain were steeped in di lute alkali and the effects on water uptake during steeping and final malt quality were determined. With the condensed tannin-free sorghum, steeping in dilute alkali led to increased water uptake during steepin g and an improvement in malt quality in terms of diastatic power and f ree amino nitrogen. These effects are presumed to be due to the alkali opening up the pericarp cell wall structure of the grain, allowing mo re rapid water uptake. Best results were obtained by application of al kali early in steeping, presumably because the Brain is less susceptib le to alkali toxicity than later in steeping. Steeping high-tannin sor ghum in dilute alkali did not improve malt quality. This appeared to b e because water uptake was not increased to the same extent as with co ndensed tannin-free sorghum, as the alkali reacted with the tannins.