Supercooled Water

What To Do

If you have a freezer then you will just need a couple of small still mineral water bottles. If you do not have a freezer then you will need a bucket, water supply, two bags of ice, half a tub of salt and a couple of still mineral water bottles.

If you are using your freezer, put the mineral water in the freezer for between one and two hours (depending on how cold your freezer is). If you are using the other method, then fill the bucket no more than a quarter full of water, stir in half a tub of salt, and place two bags of ice cubes into the bucket. Leave the bucket to stand for 15 minutes undisturbed and gently sink the mineral water bottle into the ice. Leave it in the bucket for about an hour and a half. With either approach be very gentle with the water. If you are too rough you may ruin the experiment. Once the time is up, gently take out the bottle, if the water is frozen then it has been disturbed or left in there for too long. If it is liquid then pour the carefully open the bottle and pour the water onto an ice cube on a plate. Watch as an amazing tower of ice appears before your eyes. If you are using your freezer and it didn’t work then try leaving the bottle in for longer..

The Science

For water to freeze it needs something for the ice crystals to form around. Mineral water is pure so there is nothing for the water to freeze around. The mineral water should be liquid but below zero degrees, it has been supercooled. As soon as you pour it onto an ice cube it instantly freezes. The bucket of water is a great way of doing this experiment and using salt in the water reduces its freezing point so that the mineral water can cooled down to below freezing.