Ice crystals that help ice cream maintain its structure begin to melt when they are exposed to temperatures above 0C. To prevent ice cream from melting, you must create a storage environment that is capable of maintaining temperatures below freezing. Dry ice and proper insulation will help you create a container cold enough to protect the integrity of your ice cream. This way, you can serve ice cream at a picnic or party without having to lug heavy bags of ice.
Remove the ice cream from its original container with a spatula and transfer it to a metal container that is deep and large enough to hold the ice cream when it is loosely packed. By packing the frozen ice cream loosely into the container, you create insulating pockets of cold air that will result in slower natural melting time.
Line the bottom of a large cooler with a towel. Put on a pair of thick leather or insulated gloves and place about one-third of the dry ice inside the cooler.
Gently tap the dry ice chunks with a hammer to break them into approximately 2.5 to 5 cm cubes.
Secure the lid on the metal container and lower it onto the crushed dry ice. Make sure the container is solidly seated in the dry ice.
Place the remaining dry ice in the cooler and break it into small cubes with the hammer. Pack the chunks of dry ice around and on top of the sealed metal container.
Cover the dry ice with another towel and close the lid of the cooler. Seal the lid with duct tape to prevent cold air from leaking out if your cooler does not have a secure latch.
Wear thick gloves when handling dry ice.