The effects of method of hydrolysis and source of sorghum sprout (sorghum cultivar) on the nitrogen and mineral contents of acid digests from three commercial malting varieties of sorghum were assessed. The mineral and nitrogen contents and constituents of the digests varied significantly (p < 0.05) with respect to the method of digestion, sprout source and the pair‐wise interaction of the two factors. Higher digest nitrogen, in both ICSV 400 and SK 5912, was supported by acid digestion in the autoclave while reflux digestion produced higher nitrogen in KSV 8. Of all the digests, those from ICSV 400 (both reflux and autoclave) displayed the best balance of yeast‐essential acids as well as superior growth‐promoting activity. In their growth‐producing activity, the digests also compared very favourably with seven commercial nitrogenous bases used industrially for yeast cultivation. Results suggest that sorghum sprout acid digests are good alternative sources for nitrogen and mineral nutrients in media for microbial cultivation.