a vacuum chamber where the drying process takes place. Here the product is brought to a very low pressure at which ices can sublimate, or transform directly from solid to gas without "thawing;" that is, by bypassing the liquid state. "We discovered that one of the keys to freeze drying most health products is selecting the appropriate freezing technique." says Walt Pebley, Technical Manager at Oregon Freeze Dry. "complex materials do not freeze like pure water, but pass through a variety of transitional states. An optimum freezing process is developed by measuring the multiple freezing, or eutectic, points of the material, and applying this knowledge to the overall rate of cooling and freezing."

The company monitors all processing operations with statistical quality control (SQC) and operates fully equipped QA labs. Batch-to-batch consistency is assured by microprocessor controls on each drying Chamber to continuously monitor heating, cooling and vacuum states, and product temperature.

Oregon Freeze Dry operates more that 40 freeze dryers at six manufacturing plants in the US and Europe, and runs the only three cryogeic drum freezers in the US today. It also operates three FDA-registered processing facilities; two of which are also approved by USDA, while the third operates under FDA Type 1 Drug Master File.
Freeze-drying sensitive material isn't new," Pebley says. "What we've done is make it feasible on a large scale."

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