The reactive (hydrolysis) dissolution of a solid ester suspended in alkaline, aqueous solutions has been investigated with respect to the major operating variables, such as the agitation intensity, alkali concentrations, and, most significantly, the solid reactant's loading. The main objective of the study was to explore the effects of solid clustering on the conversion behavior of the system. It has been shown that the experimentally obtained conversions of the solid reactant can be explained by invoking the notion of a declining area for solid-liquid mass transfer due to the suspended particles forming clusters or agglomerates. A semiempirical framework, for analyzing the experimental data, which utilizes a power law type of rate expression for the loss of interfacial area due to clustering, is used to provide quantitative support for the proposed hypothesis. Further qualitative evidence of cluster formation has been given in images of the suspended particles as seen under an optical microscope.