Frozen gelatin gels were freeze-dried, then sliced, microphotographed and analyzed with image analysis software. A mean ice crystal size was determined at different locations inside the gel for many operating conditions and different gelatin concentrations with ol without ionic solute (sodium chloride). Ir was observed that the mean ice crystal size grew proportionally with the distance from the cold plate. Ionic solute addition had a great influence on the mean ice crystal size. A model based on the principle of the supercooling resulting front the maximum concentration difference in the interdendritic zone was able to justify the experimental relationship and to interpret quantitatively these data.