Why is liquid nitrogen (LN2) ice cream "creamier" than regular ice cream?
The secret to creamy ice cream is the rapid freezing of the fat and water particles. The faster the ice cream can be frozen, the fewer ice crystals that can form, the creamier the concoction.
Liquid Nitrogen boils at −321 °F. Which means, holy guacamole that is cold! You'll be want to careful not to expose your skin to it or hold your hand in it, unless you're trying to lose a limb. A drop on the arm isn't going to kill you, your body temperature will ensure that the LN2 rapidly boils off, but it will feel very cold.
Here's what you need to safely make LN2 Ice Cream:
One dewar (a super insulated flask designed to hold LN2). I do not recommend using a regular store bought thermos. It may hold the LN2, but will rapidly degrade and fall apart, frozen apart by the extremely cold temperature within. Dewars are expensive, so if you have a friend at a chemistry lab, check there first.
Gloves -- you can try oven mitts or household cleaning gloves that go up your arm
A strong wooden spoon -- a metal spoon will conduct the cold and make it really uncomfortable to mix your liquid nitrogen ice cream. Go with wood.
A giant bowl
Liquid Nitrogen -- the best part. This can be purchased on site at Air Gas or similar industrial gas outlets. Expect it to cost anywhere from $3 - $8 a liter.
Your delicious ice cream recipe (mixed together, but not frozen)
Got all that? Good! We're ready to make Liquid Nitrogen Ice Cream!