The characteristics of L-ascorbic acid crystal growth in aqueous solution was studied in programmed batch cooling crystallization. Both seeded and unseeded experiments were carried out in a mechanically agitated double jacked vessel under appropriately controlled temperature. The final product size distribution was measured by laser analyser in the crystal suspension. The batch process was described by the moment equations model, and an indirect integral method was developed for the identification of the nucleation and crystal growth rate expressions. The principle of the method is that the model parameters are determined by fitting the final crystal size distribution computed from the model, by using the spline approximations of the programmed cooling curves, to the measured distribution.