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Salty Freezer

Oliver Wallace

ice cream crystals wideBy now you may have heard of Professor Bonker-Lonkas incredible portable ice-cream maker – the Wernham Salty Ice-Cream Tester Tumbler – which can freeze ice-cream using just SALT and ICE. But how on earth does this salt and ice thing really work? We got hold of inverntor April Wernham so that she could explain it to you.


“So we all know that ice cubes can make things a bit colder but even though the ice cubes are very cold (maybe as cold as -18 degrees Centigrade!) they are actually not very good at making other things freeze because they absorb heat too slowly and they can’t absorb very much heat before they melt.

This is where the salt comes in. When you add salt it acts like a little chemical engine that drives the melting process to happen much quicker than normal and forces the ice to suck much more heat in from the things near to it to help it melt.

In the Wernham Salty Ice-Cream Tester Tumbler right next to the ice is the cream, which sends its heat over to the ice and promptly freezes itself – into Ice-Cream!”


icream crystals little


Perfect but why do we need to tumble it about? To answer this we turned to Professor Bonker-Lonkas:

“Well when the cream freezes it turns into ice crystals – if it just sits still it will turn into a few big crystals which will be really hard and lumpy like ice cubes

But if you keep turning it about the crystals will keep breaking as they grow so you will end up with lots of tiny crystals and it will be super smooth and silky.

Mmm smooth silky ice cream…….”

Find out how to make your own Wernham Salty Ice-Cream Tester Tumbler here…

and to visit April in her inventors shed go here…