Key Points
The first freeze-dried meals came out of a NASA lab in the 1960s, but the first foods to ever be freeze-dried were potatoes, 700 years ago...
The low temperatures and low air-pressure levels at those altitudes were ideal for this preservation technique...
Freeze-dried foods remain shelf-stable at room temperature and retain much of the original textures and flavours when rehydrated...
Next, in the primary drying stage, air pressure is dropped and the food is heated slightly so that the water sublimates, leaving pores where it had been..
In foods where aroma plays a key role, such as coffee and herbs, the eventual flavour of the freeze-dried version is far superior to that of the air-dried..
