A big misconception when it comes freeze drying vs dehydrating is that it’s the same thing. The truth is, these food preservation processing types couldn’t be more different.
Only one similarity exists between these two food preservation processes. Both freeze drying and dehydration removes moisture from food. From there, that’s where the similarities end. Everything about these preservation methods differs from the processing, to what food you can use, to the texture and taste. The biggest difference comes with the machines used and their costs.
I’m going to give you the details about the differences between these two processes and why I use both. In this article I give you enough information for getting your food preservation system started.
Freeze Drying vs Dehydrating
The most important understanding needed about freeze drying vs dehydrating is the differences in preparing the preserved food items. Each preservation method has different rehydration methods when adding to meals.
For me, I preserve food both ways, freeze drying and dehydrating; I love my freeze dryer because it preserves almost anything while maintaining the original flavor. Dehydrating, on the other hand, greatly changes the taste, texture, and appearance of food. But, there are a few things, like jerky and fruit leather you can’t get good results in a freeze dryer.
My loyal followers know I own a Harvest Right Home Freeze Dryer and how much I love it. The Harvest Right is an amazing machine and preserves almost any food. Read my in-depth Harvest Right Home Freeze Dryer Review, for some great information.
Now down to the nitty gritty. Let’s look at what each of these machines does and how you can start your survival preparedness pantry.
Freeze Drying vs Dehydrating Comparison Table
|Reduction in Weight||Removes 98% of Water||Removes 98% of Water|
|Shelf Life||20 to 30 Years Un-Refrigerated||5 to 10 Years Un-Refrigerated|
|Nutritional Content||Retains Almost All Nutrients. Similar Nutrient Content to Fresh||Keeps Some Nutrients Except Vitamin C|
|Retains Flavor||Little to No Loss of Flavor||Drastically Changes Food Flavor|
|Space Savings||Retains Shape and Takes More Room to Store||Considerably Smaller and Saves Storage Space|
|Rehydration Time||1 – 20 Minutes in Boiling Water||5-Minutes to 1 ½ Hours in
Freeze Drying Process
Freeze drying, also known as lyophilization, rapidly freezes food then vacuums all water from the food. Flash freezing and removing the air leaves food keeps its shape and flavor. You get a finished food product that’s compact, light, and will last up to thirty years.
Benefits over dehydrating:
- Food keeps its shape.
- Lightweight for better storage.
- Food keeps original flavor.
- Food takes less rehydration time.
- Has a shelf life of up to 30 years for some foods when properly stored.
You can freeze dry almost any food except for butter or anything that has a whole lot of oil. The freeze drying process and the rapid change from freeze to vacuum keep the shape, cell structure, color, and nutrients. Your food keeps the look of fresh food and most of the nutritional value.
The freeze drying process is simple, consisting of placing food on trays inside the vacuum chamber and setting the program. From there, the Harvest Right Home Freeze Dryer handles the rest.
Temperature lowers to -30° to -50° Fahrenheit then slowly raises. At this point, the vacuum pump pulls a full vacuum inside the sealed chamber. The food warms from a solid to gaseous state, changing the ice in the frozen food to vapor, while keeping the food’s structure and nutrients.
This chill to warm process continues until the moisture sensor no longer detects water vapor. Nine hours later, depending on the food type, the dryer unit singles it’s done with a beep.
Once you release the vacuum, always check for dryness using the thickest piece of food. If the piece center is cold, it’s a sign of lingering moisture. Place the food back in the machine for additional drying time with the options listed on the freeze dryer menu.
When comparing freeze drying vs dehydrating, the processes are both fairly simple.
With freeze drying, most moisture, about 98%, gets removed from the food. Since the main source of food weight is water, between 80% and 90%, freeze dried food weighs little. The freeze dried food’s light weight makes it the perfect outdoor meal and is easy for one person to carry.
Whether camping, boating, backpacking, or wherever you take your food along, freeze dried food provides a full meal or snack.
Freeze dried food is easy to reconstitute just add water and let sit until fully rehydrated. You can rehydrate food with boiling water or cold water, but using cold water takes almost double the rehydration time. Some freeze dried foods taste just as delicious without reconstituting.
Another advantage of freeze dried food is it’s much faster to rehydrate than dehydrated food, almost half the time. You can make a hot and delicious meal in less than 10-minutes by adding boiling water.
Perhaps the biggest advantage of freeze drying over dehydrating is the taste. Unlike dehydrated, freeze dried food retains not only its fresh, original flavor but also the appearance and most nutrients.
The retention of the food’s original qualities comes from the processing. Freeze drying removes moisture from the food without using much heat which locks in flavor and nutrients. No other food preservation method does this, whether dehydrating or even pressure canning.
Freeze dried food has a texture that’s light and airy compared to the leathery sometimes tough texture of dehydrated food. Some freeze dried foods have a texture that melts in your mouth.
However, freeze dried food is fragile and crumbles easy. Take care when handling food from a freeze dryer or you’ll have beef powder instead of fajita meat.
For food like eggs or dairy, powdering works great, for a meat dish, not so much. But for large, whole food pieces or freeze dried meals, take care when handling.
When it comes to freeze drying vs dehydrating for taste, my favorite lies with freeze dried.
With the dehydration, process food dries from applying heat. Like freeze drying, 98% of the water gets removed, but with dehydration, water leaves the food without cooking it. The dehydration process drastically changes the texture of the food making it withered and hard. When it comes to freeze drying vs dehydration freeze drying is the clear winner over close to fresh texture and taste.
Benefits over freeze drying:
- More compact saving storage space.
- Easily done at home with small countertop machines.
- Considerably less expensive to process.
The dehydrating process removes most of the water found in food by using heat and blowing air. The combination of heat and air helps preserve the food making it resistant to normal bacterial growth.
When properly dehydrated, food retains most of its nutritional value except vitamin C. Since vitamin C is air-soluble the air-drying process of dehydrating causes loss of the vitamin. However, most of the remaining nutrients remain intact. Other nutrients like vitamin A remain after the dehydration process. Foods high in vitamin A, like carrots, need special storage away from light to maintain the nutrient content.
Some dehydrated foods like fruits taste sweeter after dehydrating. However the calorie value stays the same. When water gets removed, the food’s sugar becomes concentrated, giving it a sweeter taste.
Besides keeping the food’s nutritional value, dried vegetables and fruits retain their carbohydrates and fiber. With these foods being naturally low in fat and calories and high in nutrients, they make the perfect snack food.
As with freeze drying, dehydration removes 98% of the water in food. However, drying shrinks the food making it more compact, much lighter, and easier to store than freeze dried food. Dehydration gives food a shriveled appearance which plumps back after rehydrating in hot water.
While freeze drying keeps its original shape, it takes up more room and is more fragile than dehydrated food. For storage and processed weight in freeze drying vs dehydrating, I have to go with dehydration. It’s lighter, making it a great take along for back packing and camping, with an easy to store compact size.
Freeze dried foods you can eat dry without rehydration while most dehydrated foods need soaking and cooking first. While some foods require more water for rehydration and some require less, a good rule to follow is a water ratio of 2:1. Two cups of dehydrated green peas, for example, need 4-cups of water.
I’ve learned from experience that vegetables like carrots need more water and longer soaking times. Mushrooms, on the other hand, take less water and soaking time. I soak according to look and feel of the food item. Normally, you can expect 5-minutes to 1 ½ hours of soaking time when using boiling water. Which brings me to another question; boiling water or cold water.
I almost always use cold water, because warm water is a breeding ground for bacteria. If you’re like me, you may have a habit of forgetting you have something soaking. If you have it in hot water and forget, you’ve set up a food bacteria zone. I just make a habit of always using cold water. While using cold water for rehydration takes longer than using boiling water, cold water rehydration is safe.
For dishes, like soups and stews, I just throw the dried veggies straight in the pot. No soaking. Since I slow cook my soups, by the time they finish cooking, the veggies are nice and tender. The temperature is far enough above the bacteria growth level of 140° Fahrenheit.
Rehydration is an easy process, just add your food to a large bowl and cover with water. Sometimes, your food may soak up all the water and is still dry and hard. Just add more water and let soak longer. You really can’t add too much water because if you do, just drain the excess.
With dehydration, the food texture changes dramatically with most items becoming chewy and leathery. Dehydration also drastically changes the food’s taste where freeze drying keeps the original flavor. While this can make a difference in the dishes, you use dehydrated food in, some dehydrated food gets a flavor boost.
Onions, peppers, and tomatoes are foods great for dehydration. They make a perfect addition to soups and stews and the change in texture and flavor enhances these dishes. Just add them to the pot at the beginning of the cooking process.
When it comes to the food’s taste with freeze drying vs dehydrating, for me both processes are winners.
No matter which process you choose, you have the perfect food preservation system for survival prepping.
Apple Chip Snack
My family's favorite snack. This is one food I can't stock enough of and put back for my family survival prepping. It's a perfect replacement for potato chips and cookies. When it comes to freeze drying vs dehydrating, nothing does apple chips better than the dehydrator.
- 3+ Pounds Tart Apples Granny Smith
- 2 Cups Bottled Lemon Juice
- 1 Cup Granulated Sugar
- 2 Teaspoons Ground Cinnamon
Wash apples and thinly slice, about 1/8 inch, and place in a non-metal bowl.
Mix together lemon juice, granulated sugar, and cinnamon and pour over apples, covering all apple slices.
Remove apple slices from juice and shake off excess then lay slices on dehydrator trays. You need to stir the lemon juice mixture frequently to keep the cinnamon mixed in.
Place apple slices close together leaving enough space so they don’t quite touch. Place trays in dehydrator.
Set dehydrator for 12-hours or overnight. Check an apple slice from the center and the edge of the tray. If they aren’t crisp, return to the dehydrator and run for another 4 to 8 hours or until dry.
Store in an airtight storage container in a cool dark place. No refrigeration needed if completely dry.
* The pounds of apples needed depends on the size of the dehydrator. You may need to adjust the amount up or down.