Potato and waxy-maize starches were separately modified for 1 h at 65" with 0.36% hydrochloric acid in methanol, ethanol, 2-propanol, and 1-butanol. All of the modified starches were readily soluble in hot water, to give crystal-clear solutions up to a concentration of at least 20% (w/v). The modified granules were studied by light-microscopy and iodine-iodide staining. All of the modified starches retained their granule appearance, although with various degrees of damage that progressively increased from methanol to 1-butanol. Both hydrolysis and alcoholysis occurred, but to different extents in the different alcohols. The highest proportion of alcoholysis occurred in methanol where 50% of the resulting molecules were glycosides, the lowest in 1-butanol where 6% were glycosides. The number-average molecular weights of the modified starches also progressively decreased from 126,670 for the methanol-modified waxy-maize starch to 4,750 for the l-butanolmodified potato starch. The methanol-and ethanol-modified potato starches were fractionated into amylose and amylopectin components. The 2-propanol-and lbutanol-modified potato starches gave only an amylopectin component. The amylose components were characterized by gel-permeation chromatography on Bio-Gel A-Sm, and the amylopectin components, on Bio-Gels A-150m and A-0.5m. The molecular sizes of the amylose and amylopectin components progressively decreased from methanol-to 1-butanol-modified starches. Furthermore, the polymodal composition of the amylopectin component was decreased to give a more homogeneous product. Waxy-maize starch was modified in methanol and 2propanol and gave products that were of lower molecular size and more homogeneous than the polymodal native starch. It is shown that the differential effect of the different alcohols on the modification of the starch granules is produced by effecting different concentrations of acid inside the granule, where hydrolysis occurs in the lO-12% of water contained in the granule. It is postulated that 2-propanol and 'Journal Paper No. J-12431 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa. Project No. 2416. To whom inquiries should be directed.