What is Freeze Drying?

What is Freeze Drying?

Freeze drying, in a nut shell, is removing water in perishable materials in order to preserve and extend the shelf life.  When food is freeze dried and properly stored, it will last for years.  Freeze drying has three phases, freezing, primary drying, and secondary drying.


Food is frozen below its normal freezing point, reaching -30 to -40 degrees Fahrenheit, to ensure that sublimation instead of melting will occur.  This preserves its physical form.

Primary Drying Phase

This is the second stage where the sublimation will occur.  Sublimation is when the ice turns into a gas without first becoming liquid. Have you ever seen steam or fog coming off of snow?  That is the snow (solid) turning into fog (gas), which is sublimation.  This is also the longest of the phases.  Approximately 95% of the water is removed during this process.

Secondary Drying Phase

The final phase of freeze drying occurs here.  Temperatures are raised in this phase, but do not go above 100 degrees Fahrenheit for any of Hoss & Duke’s Pet Food or treats.  Ensuring the enzymes are not destroyed by high temperatures.  This process squeezes any remaining moisture out of the product usually leaving less than 5% residual moisture.

Want to try the best freeze dried treats available for your dog or cat?  Go to my Shop Page and get yours now.