Technical Abstract: Chemical loss of sucrose, and formation of degradation products including color compounds, across a beet factory's five-effect evaporator were investigated. Kinetic samples of thin juice and evaporation syrups were obtained hourly, over a six hour sampling period. This sampling period occurred once in the 1995/96 and 1996/97 campaigns. Ion chromatography with integrated pulsed amperometric detection (IC-IPAD), an accurate carbohydrate analysis technique was used to measure directly sucrose, glucose, fructose and mannose levels. Conventional sugar factory analyses for monitoring sugar losses, i.e., changes in pol, purity, pH and color, were compared to IC-IPAD analyses; purity was shown not to be viable for determining sucrose losses across the evaporator process. Color formed across the evaporators in both campaigns, with a concomitant decrease in pH. Color formation is due to a complex of reactions: Maillard reactions are more dominant at the early stages of evaporation and alkaline degradation reactions of invert sugars and sucrose at the latter stages, as indicated by color Indicator Values, invert levels and the detection of mannose. Detection of mannose in the evaporator samples, confirmed that alkaline degradation of invert had occurred. Mannose can be used as a marker compound for invert losses. A complete mechanism of color forming reactions across the evaporators is described. glucose%sucrose ratios (as measured by IC), were shown not to be viable to determine sucrose losses in these samples, and are underestimates. Excellent correlations existed between polarizations measured at 589 and 880nm for the 1995/96 (r squared=.997) and 1996/97 (r squared=1.000) campaigns.