A method of treatment of substances containing cocoa butter, particularly chocolates, which is suitable for coating machines, wherein the material containing cocoa butter is first heated slightly above the highest melting point of cocoa butter, then subjected to a two stage cooling step whereby the material in first cooled to a range approximately 30* to 31* C. by a cooling medium having a temperature only slightly lower than this range and secondly cooling the mass to 28* to 29* C. by a cooling medium having a temperature only slightly lower than this range, and then heating the material to 33* to 34* C. and subjecting to further processing (i.e. coating). The material after this treatment is in a thermostable condition, has a substantially constant viscosity and may be stored indefinitely under stirring and when maintaining the temperature of the temperature of the material.