What is Freeze Drying?
Freeze Drying in a nut shell is the process of freezing foods in a very cold (-20F or more) chamber, then heating the trays while the machine pulls a vacuum. The machine will pull until it consistently can hold the chamber below 500mTorr’s which isn’t a perfect vacuum but about 99.93% (yeah, I looked that up). This can take a long time depending on how much water is in your food and how hard it is for the liquid to escape its placement (skins on fruit for example are hard to sublimate through). As the trays warm the water in the food doesn’t melt, it sublimates and goes from ice, to vapor and then accumulates as ice on the drum. It is science so this is my best cliff notes understanding.
When the food is done, it is checked to make sure there are no cool spots in the food. I’ve had really good luck and not needed to add extra time but I usually add extra time into math to start as I really want to make sure it had that extra dry time. We package the food in mylar bags or jars depending on the usage of the product with an oxygen absorber right away and we are done!
The food will keep in the jars in dark, cool storage for a year or two. The mylar bags up to twenty years!
This past spring, 2026, I made a few videos for eager friends that I have posted that explain the process. I walk you through doing ground beef with two extra videos of some of our other foods as they are coming out of the machine. As I grow this page, I will hope to do better and produce better photos and videos.
