I'm excited that someone is going to get their hands dirty and go ahead and give malting a try. Here are some notes I've found by searching google books which pertain to utilizing sorghum:
From Handbook of Brewing page 173, "Sorghum malt starch has a gelatinizing temperature of 64 - 68 degrees C (147-154 degrees F) , 10 degrees higher than that of barley." I think the problem is that the temperature which gelatanizes sorghum's starches also denatures the necessary enzymes.
From Lost Crops of Africa: Grains By National Research Council (U.S.) Board on Science and Technology for International Development page 49, "Of all the world's ceral grains, finger millet is second only to barley in its ability to hydrolyze starches ('malting power')."
This is interesting because millet is also gluten free... May be it can be utilized to help convert sorghum. I think some of the South African opaque beers call for millet as an ingredient.
From Handbook of Brewing: Processes, Technology, Markets by Hans Michael Esslinger
Favorable malting parameters are achieved at temperatures between 24 and 26 degrees C (75-79 degrees F), which facilitate the growth of molds, however. Addition of a 0.375% mixture of borax and boric acid to soft water reduced the germ number of mold significantly.
Sorghum malts differ from barley malts in their higher gelatinization temperatures and reduced diastatic power, which can be attributed to lower B-amylase activities, while A-amylase activity at least equals that of barley malt. They are characterized by very low protein contents that might even decrease further during storage and result in diminished concentrations of soluble protein in the wort. Although the raw protein content of sorghum compares to that of barley, it can be only partially degraded into smaller fragments during mashing (as the prolamines of the Panicoideae subfamily differ from that of the Pooideae subfamily). Accordingly, the amino acid composition of wort polypeptides differs between barley and sorghm malts. However, FAN levels are in the normal range. A minimum of 5 germination days is required during malting of sorghum to ensure sufficient soluble nitrogen concentrations in the wort. This extension of the germination combined with a significantly increased degree of steeping results in elevated levels of dissolved pentosans. Therefore, the viscosity of sorghum-derived worts is slightly elevated as compared with barley malts. Moreover, sorghum malts exhibit only low diastatic activities, resulting in long saccharification times.
From Sorghum: Origin, History, Technology and Production By C. Wayne Smith, Richard A. Frederiksen page 165,
Sorghum malt traditionally is prepared at the household level by soaking or steeping the grain for 16 to 18 hours, draining, and then spreading the grain on dampened mats. The mats are covered with damp sacks and the grain is left to germinate, preferably in a darkened place, with intermittent moistening of the sacks and turning of the grain. Malting is carried out in the open or on soil platforms bordering the house. Germination is complete within 3 to 5 days and the malted grain is ready for sun drying and grinding to powder on grinding stones.
Treating with wood ash page 166
In Uganda, a traditional process used to improve the palatability of high-tannin sorghums was reported by Mukuru (1992). Cleaned sorghum grain is mixed with a slurry of wood ash. The treated grain is soaked overnight, drained, and malted. Malted grain is dried, pounded , winnowed to remove the pericarp, and ground to flour.This traditional processing, involving the addition of alkaline wood ash, significantly reduces the adverse nutritional effects of tannin in the grain and malt, and improves both protein availability and digestibility.
Sorry if this is kind of long, but I thought it might be helpful...
FYI- apparently this cyanide problem is prevalent in a lot of other fruit and vegetables, but it is in such a miniscule amount and we are so used to it that it does not matter.
