Freeze drying works by removing the moisture (water content) from your breast milk while it is in a frozen state. First, your milk will be placed frozen in a vacuum chamber. The chamber is then heated, causing the frozen water to turn into vapour and escape your milk. This process is called sublimation.
The vapour is then collected on a cold surface, where it turns back into ice and is removed from the vacuum chamber. This process leaves behind a dry, preserved powder which retains the nutritive components of your breast milk, and with a longer shelf life than your original frozen breast milk.
Freeze drying is often used for preserving foods, pharmaceuticals, and other perishable materials.
