Processing and profile of sorghum malt.
The literature on the malting and brewing properties of sorghum is reviewed. Experiments are described in which several varieties of sorghum were malted and their composition and properties compared with those of malts made from barley and wheat. Sorghum tends to have a higher protein content than barley as well as high levels of anthocyanogens, tannins and other polyphenols. The activity levels of the enzymes activated during malting (e.g. alpha amylase, beta glucanase) tend to be lower, so that sorghum malt has a lower diastatic power than barley malt and its wort has a higher viscosity. Sorghum malt worts also tend to be richer in dextrins and poorer in fermentable sugars. The author recommends adding a certain proportion of barley malt to the grist in order to improve saccharification and extract yield, instead of using industrial enzymes, and also suggests that Schizosaccharomyces pombe (a yeast which in its wild state plays a major role in the production of the traditional spontaneously fermented sorghum beers of certain African countries, as it can ferment much of the dextrin content of sorghum wort) might be used in place of conventional brewers' yeast. It is further pointed out that even the paler coloured sorghum varieties are often rather too dark to be suitable for pale lager brewing, but that the dark traditional varieties can be used to brew stout and other dark beers, not only in malted form but also roasted as a substitute for roasted barley.
Keywords : brewing composition enzymic activity malt malting properties quality sorghum