Freeze drying, also known as lyophilisation or cryodesiccation, is a low temperature dehydration process that involves freezing the product, lowering pressure, then removing the ice by sublimation. This is in contrast to dehydration by most conventional methods that evaporate water using heat.

Freeze drying results in a high quality product because of the low temperature used in processing. The original shape of the product is maintained and quality of the rehydrated product is excellent.