What is Freeze Drying?
Freeze drying is the water removal process. The goal is to extend shelf life and in this case, up to three years. Freeze drying works by freezing the milk first, then adding heat to all the frozen water to turn into a vapor. We don’t ever use heat that exceeds natural body temperature. This is known as Sublimation.
The Three Phases
Freezing
The milk is frozen under atmospheric pressure.
Sublimation
This is the primary drying phase. The pressure is lowered and heat is added. The vacuum pump in the machine speeds this process up. About 95% of water is removed in this phase.
Drying, Adsorption
In this process the water molecules are removed. The bonds are broken between material and water. Most material will only retain 1-5% of its moisture
Is freeze drying healthy?
Freeze drying is the one of the best ways to retain nutrients, color, flavor, and structure. It’s also the most effective way to retain antioxidants. It stops the growth of bacteria, yeast, and molds due to the lack of moisture in the product. Freeze drying doesn’t affect the calorie count, fiber content, or the overall amounts of minerals. It can make a slight difference in vitamins such a folate and vitamin C