For two years we have been adding food from our garden to our long term food storage with a home freeze dryer unit. Today we added some peeled cucumber slices to our long term storage. Considering these cucumbers do not have fat or sugar in them, they should have an expected shelf lift of 30 years with nearly zero nutrient value loss.
Our home freeze dryer unit is a large Harvest Right unit that uses zero low temperatures and vacuum pressure to remove water from food. In this picture you can see the rack which holds trays of food inside a long steel cylinder. That is the vacuum chamber. If you look on the side of the chamber you will see the accumulated water frozen to the outside of the drum.
Once the freeze dryer cycle is complete, the food is placed into a mylar bag with oxygen absorber and sealed tight with an impulse sealer. The duration of the freeze dry cycle can vary based on the amount of food, the water content of that food, the thickness of the food being freeze dried, and skin (such as blueberries) that slows down the water removal. We expect an average of 40-48 hours for a complete freeze dry cycle.
Here is a tray of cucumber slices right out of the freeze dryer. They are freeze dried and ready to placed into our long term storage. During the freeze dry process they have lost over 90 percent of their original weight, all water. They can later be eaten raw, just as you see them on this tray, or reconstituted in water.
Unfortunately a home freeze dryer is a significant investment. It took us a year to save up for ours. If you're interested in these units, check out the Harvest Right website.