Abstract A study was made on sulfuric acid-catalyzed hydrolysis of lactose with the intent to neutralize with lime and thereby reduce the amount of soluble salts in the resulting syrup. Acid concentrations ranged from 1 to 3N while lactose concentrated varied from 5 to 40% (wt/wt). Hydrolysis by sulfuric acid was noticeably slower than by hydrochloric acid. The off-color that developed depended on the time of hydrolysis, lactose concentration, type of acid, and acid concentrations. In contrast to enzymic hydrolysis, no oligosaccharides could be detected during acid hydrolysis.