This hot ice experiment may look cool, but it’s hot to the touch! Learn all about the science behind hot ice below

What you need:
4 cups of vinegar
4 TBSP baking soda
Medium pot
Liquid measuring cup
Plate

How to make hot ice:
Pour 4 cups of vinegar into a medium pot and slowly add 4 tablespoons of baking soda to create a sodium acetate solution.
When the solution starts to fizz, keep stirring until it stops producing bubbles and all of the baking soda has dissolved.
Boil the solution over medium-low heat until you can see crystals on the side of the pot. Then, pour the concentrated solution into a liquid measuring cup and let it sit in the fridge to cool.
Scrape some of the solid sodium acetate off the bottom of the pot and put it on a plate.
Slowly pour the solution on top of the solid, and watch crystals form!

What’s going on?
When you create, boil down, and cool the solution, you’ve dissolved way more sodium acetate than you could mix into the same amount of cold water. In other words, you’ve made a supercooled solution. That’s the scientific term for a material that is cooled down past the point where it would normally become a solid.

A supercooled solution will begin to crystalize with the slightest movement or addition of crystals, which is exactly what you saw in this experiment. All the extra sodium acetate in the solution crystallized very quickly and became solid, which is what created the pillar of “ice” on the plate. This crystallization process releases heat, which is what makes the crystals warm to the touch.