The objective of this work was to determine the effect of cold storage of milk on selected functional properties of micellar casein. The cold storage of milk was found to modify the molecular state of casein, changing its functional properties. The time of enzymatic coagulation was lengthened and the amount of chymosin-released peptides increased. The modification of molecular state caused the formation of milk gels of a changed structure. The changes induced by low temperature did not reverse on balancing the protein system of milk by stabilization (22724 h) or termization (65°C/15 s).