250g cleaned raspberries
500ml liquid nitrogen
Pour the liquid nitrogen into an insulated container. Carefully add the raspberries and stir gently for two minutes. Remove the raspberries with a slotted spoon and place on a cutting board or in a large, shallow dish. Gently tap the berries with a heavy spoon until they break apart into individual drupelets. Store in an airtight bag in the freezer until ready to use.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.