Tapioca and farinha de mandioca starches were converted to glucose in a batch laboratory-scale process by the use of a jacketed, stirred-tank reactor. Liquefaction or thinning of the starch slurries was carried out with a thermostable, bacterial cu-amylase that is active and stable in starch solutions at temperatures above 100°C. The resulting 2-3% dextrose solutions were cooled to 60°C; the pH was adjusted to 4.8-5.0 and saccharified with low concentrations of a fungal amyloglucosidase. Yields of approximately 1OOg glucose/lOOg starting material were obtained after 12-24 hr saccharification for tapioca starch, and after 24-36 hr for farinha de mandioca starch. Rheological problems and potential industrial applications of the processes are discussed.