When a phytase solution, soluble starch, and sorghum liquor wastes were mixed at the ratio of 1:1:10 (v/w/w), the residual phytase activities after 30 min of treatment at 70 and 80 degreesC were respectively, about 90% and 18% of that at 37 degreesC. After 10 min treatment, the residual activity was 67% at 80 degreesC and 10% at 90 degreesC.