The chocolate tempering process based on seeding the melted chocolate with the solid chocolate grains is studied. A model is developed to enhance the understanding and the control of the process. This model aims to predict temperature field during melting and crystallization of the product. The heat transfer problem is simplified by using an effective thermal conductivity for modeling the mixing obtained with a newly designed stirrer. The parameter value is fitted on the experimental results. The heat conduction equation is solved using Comsol. The melting of cocoa butter particles serving as seeds is added to the model using a sink term having the form of a kinetic reaction whose parameters are identified from an adiabatic melting experiment. The resulting model gives an accurate prediction of the cooling rate and the temperature field within the melted chocolate seeded with small solid grains. (c) 2008 Elsevier Ltd. All rights reserved.