Video: The worst part about making your own ice cream is waiting for it to freeze. This clever DIY machine makes your homemade ice cream ready to eat in a matter of minutes. In this video from the DIY Perks YouTube channel, Matt Perks shows how to build an instant ice cream maker at home. To build your own, you'll need a metal tray of some kind with a flat bottom, a very large heat sink, a large pan filled with water that the heat sink can rest in and some thermoelectric Peltier elements. You'll also need a power supply unit that can put out at least 400w (an old PC unit will do).
Once it's all put together, the Peltier elements act like heat pumps, making one side of them very hot, but the other side very cold. The cold side, that's attached to the metal tray, will rapidly freeze your ice cream mixture so it's ready to eat in less than a couple minutes. The tray Perks uses in the demonstration is only large enough to make a single serving, but you could easily use a larger tray as long as you had more Peltier elements and a larger heat sink. You can find a complete build list at the link below.