Does cooking oil expand in the freezer?

Cooking oil does not expand in the freezer. In fact, most cooking oils will solidify or become more viscous when frozen. This is because the fatty acids in cooking oils are typically unsaturated, which means they have double bonds between the carbon atoms in their chains. These double bonds cause the fatty acids to bend and kink, which prevents them from packing together tightly. When cooking oil is cooled, the fatty acids become even more kinked and twisted, which makes them even less likely to pack together tightly. As a result, cooking oil expands when it is frozen.

The only exception to this rule is coconut oil, which is made up of saturated fatty acids. Saturated fatty acids do not have double bonds between the carbon atoms in their chains, so they can pack together tightly. This means that coconut oil does not expand when it is frozen.