based on the basic principles of these two food preservation processesis Removing water from food to extend its shelf life. But the difference is that freeze drying, which is drying food through freezing, can remove up to 98% of the water from the freezing process under vacuum pressure. Drying can remove about 80% of the water from food when it has less moisture. It is therefore not surprising that freeze-dried food can be preserved for a longer time without worrying about mold, bacteria, or decomposition over time.