History of the freeze-drying process
Drying / dehydrating potatoes
Although nowadays techniques have improved, the principle of freeze-drying was first applied in South America centuries ago. The Incas used it to preserve their potatoes. After the harvest, the potatoes were removed of their skin and were left outside during the freezing cold night. Then during the day, the frozen potatoes were laid out to dry in the hot sun whereby the moisture evaporated. By repeating this ritual over several days, the potatoes could be kept for at least a year. And just to think that in Europe it would take another hundred years before the refrigerator was invented and food could be kept much longer.
Second World War
The Second World War brought about the development of the freeze-drying process in rapid tempo. The American Ministry of Defence saw freeze-drying as the ideal method for preserving blood plasma and penicillin longer. Several decades later, NASA also recognised the advantages. Up until today, the American Space Travel Organisation has applied the principle in order to keep food freight in space shuttles as light as possible. Since 1960, more than four hundred different types of freeze-dried food have appeared on the supermarket shelves. The most well-known of which is freeze-dried coffee.