The
process of freeze drying (lyophilization for the hi-tech
crowd) involves harvesting the plants at their peak.
They are then washed in fresh spring water and sprayed
clean.The cleaned plants are immediately frozen to
provide for the necessary conditions for low temperature
drying. The plants are then placed under a vacuum.
This enables the frozen water in the herb to vaporize
without passing through the liquid stage, a process
known as sublimination. Low temperature condenser
plates remove the vaporized water from the vacuum
chamber by converting it back to a solid. This completes
the separation process.
After the vacuum has been introduces
there is about 4-5% of moisture left in the plant
material. To reduce this final moisture content, low
temperature heat is applied to the frozen material
to accelerate sublimation and pull off the remaining
moisture. |