AbstractThree crude glucoamylase preparations fromRhizopussp.,Chalara paradoxaandAspergillussp. K‐27 were used to determine the digestibility of raw starches from eight sweet potato varieties. Granule sizes and amylose contents were also measured. The average granule sizes ranged between 10.5 and 14.2 μm. The amylose contents varied between 18.2 and 21.8%. The hydrolysis rates for the raw starches by any of the three glucoamylases were similar. However, starch of the variety Hi‐starch had a slightly lower hydrolysis rate than other starches whenRhizopussp, enzyme was