Why Are Oils Liquid at Room Temperature While Fats Are Solid?

In general, if the majority of fatty acids in a triglyceride source are saturated, then it most likely will be solid at room temperature. Contrarily, if a triglyceride source contains a greater percentage of unsaturated fatty acids, especially PUFA, then this source will most likely be liquid at room temperature. Saturated fatty acids are straighter than unsaturated fatty acid. This allows them to pack closer together and to be more solid. Take a look at Table 5.2 and notice how the oils have a higher percentage of unsaturated fatty acids while the more solid fats (lard, tallow, etc.) have a high percentage of saturated fatty acids. Despite their names, palm oil and palm kernel oil are more solid at room temperature.