The polymorphic behavior and thermal properties of cocoa butter have been investigated by means of programmed temperature x‐ray diffraction and differential scanning calorimetry. The relationship of this polymorphism to the technical problems of “tempering” and “bloom” development is discussed. Cocoa butter containing, respectively, milk fat and a bloom inhibitor, and some alternatives to cocoa butter have been studied. These results have provided information that will help determine process conditions for these particular fats.

The DTA (differential thermal analysis) cooling curves of fats are simpler than the melting curves because complicated effects due to polymorphism are not obtained. The cooling curves of some synthetic glycerides are presented. Fractions of defined glyceride composition are obtained from palm oil, cotton-seed oil and soya bean oil and examined by DTA. A number of other oils and hydrogenated oils are examined and the DTA curves interpreted in terms of their glyceride composition.