Freeze-dried food lasts a long, long time, which is why backpackers and those prepping for a doomsday disaster keep supplies of it. Freeze-dried cottage cheese, for example, keeps for at last 30 years unrefrigerated, according to the Mother Jones website. Freeze-dried foods last even longer than dehydrated foods, because the process removes more moisture. Camping supply stores sell freeze-dried food, but you may make your own. You can freeze-dry just about anything, including fruits, vegetables, dairy products, seafood and meat. Simply add water before eating.
Cut the food you want to freeze-dry into small pieces. Large pieces take longer to freeze dry.
Place the pieces of food in a single layer on a baking sheet. Space the pieces evenly and make sure they don’t touch each other.
Adjust the temperature in the freezer to the lowest setting. Put the baking sheet in your freezer and allow the food to freeze for a full week. Avoid opening the freezer door if you can during that time. If you plan to freeze-dry a lot of food, you might want to purchase a freezer to use for that purpose.
Remove a piece of food from the freezer after one week and allow it to thaw. If it appears black in color when it thaws, the food is not ready yet. Dispose of that piece of food and leave the rest in the freezer for two or three more days. Then take out another piece of food and let it thaw. The food is ready when it thaws without turning dark in color.
Put the freeze-dried food in freezer bags and use a vacuum sealer to seal the bags. If you do not have a vacuum sealer, press out as much air as possible before sealing the bags.
Store freeze-dried food at temperatures of 60 degrees Fahrenheit or lower.