How to Freeze Dry Food (The 4 Best Methods)

If you’re looking for ways to preserve food, freeze-drying is an excellent method. Then, when the seasons change and your favorite foods get harder (or more expensive) to buy, you’ll always have some on hand.

There are many great reasons to use freeze-drying over other preserving methods, including the fact that it can be kept for decades, helps retain flavors better, and is a much more compact method.

In this guide, we will discuss four methods for freeze-drying food. These include using a freeze dryer, a freezer, dry ice, and a vacuum chamber. Hopefully, you have the tools available to use at least one of these methods.

Before we start discussing the methods, we want to advise you on how to prepare the food for freeze-drying and what the best foods to use are. Hopefully, this helps you get better results. 

What Is the Best Way to Prepare Food for Freeze Drying?

• Buy and use the freshest food available. This will help ensure its longevity when freeze-drying.
• Thoroughly clean the food. This will remove contaminants and dirt, ensuring your food tastes good when eventually eaten.
• Cut food into small pieces. This will help eliminate moisture which will ensure your food doesn’t spoil.

What Are the Best Foods to Freeze Dry?

The best foods to freeze dry are vegetables and fruit. However, many people have success freeze-drying food items like meat, dairy, cooked meals, and desserts. Always avoid food items like honey, peanut butter, and jam, as they are not suitable.

Method 1 – Use a Freeze Dryer

The first method for freeze drying we want to tell you about is the most obvious. It involves using a freeze-dryer. If you have this specialist appliance, the whole process of freeze-drying is much simpler. If you don’t have a freeze dryer, you can skip straight down to method 2.

Follow these instructions to freeze dry food in a freeze dryer:

1. Place the freezer dryer trays on your bench.
2. Place the food you want to freeze dry on the trays (the food cannot sit higher than the tray).
3. Put the tray in your freezer dryer.
4. Close the freeze-dryer door.
5. Set the temperature to between -40- and -50 degrees.
6. Leave it to freeze for 24 hours.
7. Once the process is complete, place the food into mylar bags and seal them airtight.
8. Store the bags of food in your freezer or pantry.

Method 2 – Use a Freezer

If you don’t have a specialist freeze dryer, you can use your home freezer to freeze dry food. This makes freeze-drying assessable to most people.

Follow these instructions to freeze dry food in a freezer:

1. Place the food you want to freeze dry on a flat tray (make sure it’s evenly spread).
2. Put the tray into your freezer. It’s a good idea to check your freezer temperature settings to ensure they are set correctly.
3. Leave the tray in the freezer for 2 to 3 weeks.
4. After the required freezing time, remove the trays from the freezer and place the food into air-tight bags.
5. Store the bags in your pantry or freezer.

Method 3 – Use Dry Ice

If you don’t want to wait 2 to 3 weeks for your food to freeze dry in the freezer, you can use dry ice to speed up the process. Dry ice works well because it removes moisture from the food very quickly.

Follow these instructions to freeze dry food using dry ice:

1. Put the food you want to freeze dry into freezer-safe bags.
2. Put the freezer-safe bags of food into a cooler (make sure you have enough space for the bags and the ice).
3. Cover the food bags with dry ice.
4. Leave for 24 hours before removing the bags.
5. Store in your freezer or pantry.

Method 4 – Use a Vacuum Chamber

The final method we want to discuss involves using a vacuum chamber. These devices can be expensive and not commonly found in residential homes. They are more likely to be on commercial premises.

If you do have a vacuum chamber, follow these steps to freeze dry food:

1. Place the food you want to freeze dry on a flat tray (make sure it’s evenly spread).
2. Place the tray into a freezer.
3. Once the food is frozen, remove it from the freezer and place it into the vacuum chamber. You need to set it to 10 degrees at around 120m Torr.
4. Leave the food in the chamber for 7 days.
5. Once complete, place the freeze-dried food into air-tight containers.
6. Store in your freezer or pantry.

How Do I Rehydrate My Freeze-Dried Food?

Now that you have successfully freeze-dried your food using one of the four methods above, we want to end by telling you how to rehydrate it. If you freeze dry food, like small pieces of fruit and vegetables, you can eat them straight out of the bag or container or sprinkle them with a small amount of water to bring them back to life. If you want to rehydrate a whole meal or other large items, place the bag or container in a warm place. After a few minutes, they should be able to be used.