AbstractThe glycerides, 2‐oleopalmitostearin and 2‐oleodistearin, which are important components of confectionery fats, were synthesized, and their melting behavior and dilatometric properties were determined.Each glyceride was found to have four melting points: 18.2, 24.5, 33.0, and 37.4°C, for 2‐oleopalmitostearin; 22.8, 30.0, 37.7, and 42.8°C, for 2‐oleodistearin. The rate of transformation of the thermodynamically unstable polymorphs at temperatures just below their melting points was found to vary from a few seconds to more than eight days.For each glyceride, expansivities were determined for three polymorphs and melting dilations for two polymorphs. Mixtures of the two glycerides were examined dilatometrically and found to behave in some respects as single components. The mixtures were readily tempered so that both components were in the same polymorphic form, and expansivities and melting dilations were obtained for mixtures in three polymorphic forms.Dilatometric data also were obtained for a sample of cocoa butter and a sample of sweet milk chocolate of the coating type.