Does vegetable oil expand when frozen?
Very few substances do – they are characterized by the formation of open (usually tetrahedral) lattices as a solid. Water is the best known, along with the elements silicon, antimony, bismuth and gallium. “Vegetable oil” is a wide-open term, which could refer to a mixture of various oils, or to a category of substances from individual vegetables – sunflower oil, safflower oil, etc. Even the single-vegetable oils are not pure substances, and unlikely to meet the requirements for expansion – I can find no evidence of any that do!
