If you're an impatient ice-cream lover who likes to experiment in the kitchen, mathematician Matt Parker has the perfect recipe for you: instant ice cream. All you need (apart from your regular ingredients, of course) is a fire extinguisher and some extra-insulated gloves, and you can start mixing.
Assemble the ingredients
Make up your ice-cream mix of two parts cream, two parts milk and one part sugar. Add in any extra flavours such as vanilla and dump the mix into a cylindrical measuring jug. Get yourself a 1kg carbon dioxide fire extinguisher, a cloth pillowcase and some padded gloves to prevent frostbite.
Make dry ice
Loosely tape the pillowcase on to the nozzle of the fire extinguisher, to collect the dry ice. Start pumping the fire extinguisher repeatedly to discharge the carbon dioxide into the pillowcase -- dry ice will immediately start forming. It is -80 degrees celsius, so keep any bare skin well clear of the nozzle.
Set up the freezing system
Once you've got your pillowcase full of dry ice, rip it off the extinguisher and tip it into a large glass mixing bowl. Lower the measuring jug filled with the ice-cream ingredients into the bowl of dry ice, and start packing in the ice firmly around the jug, using your gloved hands.
Freeze your mix
Start mixing the ingredients in the measuring jug with an electric whisk, while it is submerged in the dry ice. "Don't mix too quickly, because it might all melt before the dry ice has done its work," says Parker. Once it's all frozen, carefully remove the whole jug (it's cold). Your ice cream is ready to eat.
Eat safely
Be very careful never to add any dry ice directly into the ingredient mix, because you might accidentally swallow it and then you run the risk of burning your insides. "And even if the dry ice is fully melted, it tastes fizzy and acidic, so it's best to avoid this," says Parker.
Bon appétit.
This article was originally published by WIRED UK
