How Does Freeze Drying Work?
Freeze drying is a process that removes water molecules (in the form of ice) from a material via sublimation, which occurs when:
...a solid (ice) changes directly to a vapor without first going through a liquid (water) phase.
Source: SP Scientific: Basic Principles of Freeze Drying
There are three steps to achieve successful sublimation:
- The product is frozen.
- The product is placed under a vacuum that is below the triple point of water.
- Heat energy is added, this triggers the ice to sublimate directly into a gas.
This chart explains the scientific difference between sublimation and vaporization in a bit more detail:
The end result of this sublimation process is that a freeze dried material will be extremely dry, however, since the material hasn't been 'cooked' like a traditionally dehydrated material would be, it will also be remarkably well preserved. This is why freeze drying is widely used to preserve everything from pharmaceuticals to flowers.
Types of Freeze Dryers
The configuration of the machine that is used to freeze dry a product matters - a lot. Some machines are specialized for floral preservation, small scale pharmaceutical grade use, mass production of herbal products, etc.
In terms of producing freeze dried supplements, only the relatively rapid cycle 'food style machines' are used. Technically either an oil heating or an electric heating machine could be used. However, oil heating machines do not produce as high quality of an end product because it's harder to control the temperature during the drying phase (certain parts of the material being freeze dried can overheat). This doesn't really matter as much when freeze drying herbs but it can be damaging to glandular supplements.
All of the products we sell are produced via machines with electric heating elements.
Why Supplements are Freeze Dried
There are two main advantages to manufacturing supplements via freeze drying:
1. Freeze drying preserves delicate nutrients, proteins, enzymes, tissues specific factors, etc. Many of these compounds would be destroyed or damaged if the material was preserved using other methods.
2. Freeze drying radically increases shelf life without the need for traditional preservatives, additives, etc.
