Freeze-drying (also known as lyophilization) is a process where frozen raw materials are placed in a refrigerated vacuum chamber and without thawing the material it is dehydrated – the ice is sublimated into water vapor and extracted. 

During the freeze-drying process the cell structure of the ingredient remains intact, and because little or no heat is involved in the process, the product retains its natural nutritional values, color, flavor, odors, and it rehydrates better, than in other drying methods.