You can supercool hot ice or sodium acetate so that it will remain a liquid below its melting point. You can trigger crystallization on command, forming sculptures as the liquid solidifies. The reaction is exothermic so heat is generated by the hot ice.
Make Your Own Salt and Vinegar Chips with Homemade Sodium Acetate
wk 3 Answer to Common Hot Ice Questions: This is a crystal of sodium acetate trihydrate, sometimes known as hot ice because it somewhat resembles water ice and because it generates heat when it crystallizes.
How to Make Sodium Acetate From Household Ingredients
How to make "vinegar powder" (Sodium Acetate). Otherwise known as the tasty sour stuff on Salt & Vinegar chips and popcorn. sodium bicarbonate (baking soda) - acetic acid (vinegar) - microwavable glass or ceramic containers - coffee filters - spoon
Hot ice, scientifically known as sodium acetate, is a liquid that will turn solid at the slightest provocation. Touching it with your finger or bumping it too hard will cause it to spring from a clear, water-like state into solid ice-like crystals.