This is one experiment that we will have to try again! It sort of worked but not entirely. The aim is to make the water in the bottle freeze instantly.
First, cool a bottle of water in the freezer for a few minutes. Then, remove the bottle from the freezer and place it into a container of ice cubes. Add a generous amount of salt. After a few minutes remove the water bottle from the container of ice and salt and hit it against a hard surface.
If the experiment has worked ice crystals will form at the top of the bottle and make their way down through the bottle until you have a bottle of ice! Ours didn’t but from researching this process does take some trial and error. Next time I will have a thermometer handy to keep an eye on the temperature of the ice and water in the container as one source recommended getting the temperature to -8C before taking the bottle out and hitting it against the hard surface. I’ve also read that using purified water produces better results.
Watch this space for an update when we have attempted this again or give it a try yourself!