How do you dehydrate ice cream like for astronauts?

Answer 1

The process is called freeze drying and can be applied to anything, not just ice cream..

1. Freeze the material.
2. Place it in a vacuum chamber.
3. Pump the air out of the vacuum chamber.
4. Water sublimes from the material into the vacuum.
5. When fully dehydrated let air back into the vacuum chamber.
6. When back at ambient pressure, remove material from vacuum chamber.

The advantage of freeze drying over other dehydration methods is it retains shape, color, and texture of the material. The disadvantage is the cost.