Freeze-Drying

Freeze-drying, also known as lyophilization, is a method of food preservation by which frozen items are dehydrated in a vacuum. During this process, foods are placed in a pressure chamber and undergo sublimation, whereby ice converts directly from a solid to a gaseous state. Moisture quickly escapes as vapor, and the dried items are left with a porous texture. Unlike many other drying approaches, freeze-drying allows the final product to largely retain its shape, size, flavor, and nutritional makeup.