Self-Rotating Ice

Who doesn't want ice cubes that rotate as you drink?

Read on for an instructable that is almost embarrassingly easy...

You need ...

• A cylindrical ice cube mould - more on this in the next step.
• Coloured liquid - I used squash (cordial), but you could use any coloured, edible liquid, such as food colouring (you could use two colours if you want).
• A mixing vessel - jug, mug, glass, whatever
• Water
• A freezer
• Wide drinking glasses, such as whisky tumblers

For this project to work, your ice "cube" actually need to be a cylinder, longer than it is wide (so that it floats on its side).

I used a 35mm film cannister that I had left over from the days I took photos on actual film. Film may be scarce, but the cannisters are still available here, but you can use any cylinder that will hold water and not burst when the water freezes.

Prepare your coloured liquid as required (such as putting a few drops of food colouring in half a glass of water), and fill your mould just under half-way up.

Make sure you have a clear, level space in your freezer, lay your mould on its side, and leave it to freeze.

Once the first half is frozen, top off your mould with either plain water, or the water coloured with the other colour, and put it to freeze again.

So, this is the part where I tell you how to make the cubes rotate.

Are you ready?

Sure?

Check the next step...

OK, so the secret is, you put one in your drink!

That's it.

Most people don't realise that ice cubes naturally rotate, because they never melt evenly. Making the cube into a cylinder makes it easier for the ice to roll, and adding the coloured layers to the ice just makes the rotation visible. As the bottom melts away into the drink, the top eventually over-balances the cube and it turns.

The only real secrets are to give the cubes space to turn (hence the wide glass) and make the "cubes" of a rotatable shape - a round or square cross-section. A wide or flat piece of ice won't rotate.

This video is a time-lapse, one frame per second, so don't blink or you'll miss the ice turning over:

(Thanks to Connor for help with the timelapse - go see his stuff on Instagram, maybe give him a follow.)