What is freeze-drying?
Floral freeze-drying is a method of preserving flowers by removing the moisture from them through a process called sublimation. Sublimation means to transform moisture directly from a gaseous state to a solid state, without ever becoming a liquid. This requires a special machine called a freeze-dryer. The flowers are rapidly frozen at sub-zero temperatures in a large vacuum chamber in the freeze-dryer. The moisture is then turned into ice crystals, which are extracted by a vacuum pump, and collected in a smaller chamber. Floral freeze-drying is relatively new, although the U.S. Army developed it in the 1900s as a method to preserve food supplies. It was first introduced in 1989 and has gained much popularity as a method of preserving flowers as techniques and pre and post treatments have been developed. Other methods of preserving flowers, such as pressing, air drying, and drying using silica gel, do not produce the natural results that freeze-drying produces.
