EFFECT OF GERMINATION CONDITIONS, WITH OPTIMIZED STEEPING, ON SORGHUMMALT QUALITY - WITH PARTICULAR REFERENCE TO FREE AMINO NITROGEN

Using optimised steeping conditions for sorghum. the effect of various germination parameters (time, temperature and moisture) on the qualit y of sorghum malt for brewing purposes (in terms of diastatic power, f ree amino nitrogen and hot water extract) and on the associated maltin g losses, was investigated. Over the range studied (2, 4 and 6 days), the quality of the malt and the losses incurred during malting increas ed with increasing germination time. In general, the optimum germinati on temperature was between 25 and 30 degrees C. and 18 degrees C was f ound to be sub-optimal for the development of malt diastatic power. Th e quality of the finished malt and the associated malting losses were significantly correlated with the moisture content of the green malt. The root and shoot portion of the malt was found to be rich in free am ino nitrogen (more than four times richer than the berry portion). Alt hough a relatively small proportion of the total weight of the whole m alt. the roots end shoots were found to contribute a substantial amoun t (as much as 61% under certain circumstances) to the whole-malt free amino nitrogen.