The evaporation of sugar cane juice in a climbing/falling film evaporator was observed. Experiments were performed in a transient-batch, single-effect process with sugar juice concentrations varying from 15 to 40 Brix. In a traditional multiple-effect evaporator used in the cane sugar industry, this concentration ranges from that of the inlet of the first effect (15%) to that of the outlet of the third effect (40%). The variation in overall heat-transfer coefficient related to juice concentration was calculated, as well as surface-heat coefficients on the solution side and temperatures of the heating surfaces. A relative, more general, overall heat-transfer index was proposed. (C) 2003 Elsevier Ltd. All rights reserved.