The history of freeze drying goes back to the ancient Inca’s, who preserved their food stuff by freezing it in the mountains in winter time. At the same time the frozen water is removed through the low vapor pressure of the water in the surrounding air at those high altitudes. Of course this process was rather slow, but during the drying process the quality of the food was maintained due to its frozen state. Once dried the food materials like potatoes and vegetables showed a remarkably increased quality over time. It is only since the WWII that this way of drying is converted into an industrial method for the preservation of materials.