How Freeze-Drying Works

Astronaut ice cream
"Astronaut ice cream," the classic freeze-dried treat for kids. See more pictures of classic snacks.

­ Freeze-drying, or lyophilization, is like "suspended animation" for food. You can store a freeze-dried meal for years and years, and then, when you're finally ready to eat it, you can completely revitalize it with a little hot water. Even after all those years, the taste and texture will be pretty much the same. That's some trick!

In this article, we'll explore the basic idea behind freeze-drying, and we'll look at the different steps involved in the process. We'll also see how freeze drying is different from ordinary dehydration, and we'll find out about some of its important applications.