Product Description Vacuum freeze-drying is one of the most gentle drying methods available. It is based on the principle of sublimation, in which a solid phase transitions directly into a gas phase. The material to be freeze-dried is placed in a vacuum drying chamber, and the water vapor produced is condensed into ice by the cold trap, effectively removing moisture from the chamber. A vacuum pump evacuates the air from the drying chamber, excluding water vapor. The baffle