SUMMARY— The relative dielectric loss factor in aqueous solutions of nonfat dried milk has been studied through chemical simulation of its major constituents. This study shows that milk dielectric loss cannot be predicted simply on the basis of its chemical composition. It does, however, provide a conceptual basis for milk modeling which leads to a more general understanding of food dielectric properties. The focal point in milk simulation was shown to be a complex relationship of solute-solute and solute-solvent interactions which reduce the dielectric loss factors to levels substantially lower than those predicted by considering only chemical composition. These include both binding and nonbinding interactions of the solutes. The binding effects are believed to result from the incomplete dissociation of milk salts in a saturated ionic environment and are reflected by a reduction of specific ion activities in solution. Nonbinding effects, on the other hand, are seen to result from the formation of hydrated ion complexes. These effects, in conjunction with chemical composition, are shown to completely determine the dielectric loss level in dried milk solutions.