What's the Difference Between a Freeze Dryer and a Dehydrator?

When it comes to preserving fresh food for long periods, you’d want to remove the moisture. Moisture is what causes food to spoil without any preserving agents. In an ideal scenario, you’d want to reduce the need for preserving agents to maintain the natural flavor of food. When removing moisture in food, two things come to mind: Dehydrators and Freeze Dryers.

While they both preserve food by removing moisture, they differ in how each operates and the end product they create. If you decide on getting either machine, here are some points that will help you decide which is best for you



Dehydration Process

Dehydration is a simple process and is as easy as laying down your food material, such as herbs on a mesh screen and air dry to preserve it. By air drying it, moisture is eliminated, which prevents bacteria from developing inside your food.

Dehydrators take this concept up a notch and let your material dry faster at temperatures between 95 – 155 degrees Fahrenheit. The time and heat depend on your material, delicate ones, such as herbs dried at lower temperatures, while meat takes a hotter temperature.



The Freeze Drying Process

Freeze dryers are a little more complicated as it features three steps to remove as much moisture inside. Unlike dehydrators, freeze dryers take your material to a process called Lyophilization.

In Lyophilization, your material is taken to -30 degrees Fahrenheit to freeze the water content, usually taking around nine hours, depending on the Freeze Dryer. After that, the freeze-drying chamber gets sealed in a vacuum, expelling the ice as vapor. This process is repeated until moisture levels are below 5 – 10 percent.



Size and Weight


Freeze Dried Bananas vs Dehydrated Bananas


Dehydrators are smaller compared to freeze dryers. They easily fit in your kitchen and weigh an average of around 13 pounds. Some appliances like the air fryer also integrate dehydrator features.

On the other hand, freeze dryers take up more space in your home. Many freeze dryers in the market take up as much space as a consumer refrigerator. On top of that, some freeze dryers need a vacuum pump to facilitate the extraction of the oil required for the freeze dryer.




Dehydrators are relatively cheaper and can be had for as low as $100. Freeze dryers cost more, with the cheapest amounting to a little less than $2,400. This amount does not include the vacuum pump, which also needs oil.

Dehydrators cost less to use in the long term and need not run as long as Freeze Dryers. That translates to less power consumption.

Freeze dryers, meanwhile, need oil changes periodically, although there’s an option for an oil-less pump. And while they consume more power than a dehydrator, they have a larger capacity for processing.





Freeze Dried Apple vs Dehydrated Apple


Dehydrated and freeze-dried food must be stored in airtight containers with oxygen absorbers if you want to keep them good for longer. But there’s a difference when it comes to how long they stay good when left exposed.

Dehydrated foods take longer to rehydrate, which is why they can last longer when placed in a humid environment. Freeze-dried food, however, absorbs moisture faster, which allows them to rehydrate more quickly.

When it comes to shelf life, dehydrated food can last on an average of three years, depending on the food preserved. Freeze-dried food can last at least 20 years and around 15 years for high-fat content food.

When it’s time to prepare it, dehydrated food material gives you the option to eat it as it is, such as jerky and raisins, or rehydrate it with a lot of water and slow cooking, such as stews and soups. Dehydrated food is also smaller than its original form.

Freeze-dried food is lighter and needs less water to rehydrate. They often have a melt in your mouth feel, which is why you can have a meal ready within 10 minutes made of rehydrated freeze-dried foods.



Which one should you get?

A dehydrator is a good option for those on a budget and who do not have the luxury of space. It fits easily on your countertop and is sometimes comes included with other kitchen appliances.

A freeze dryer is a good option for anyone who has space to spare for a more massive machine and wants a longer-term solution for preservation. As freeze dryers are a hefty investment, it’s also best to be preserving large amounts of material to make the most of it.

Dehydrators and freeze dryers are welcome solutions for preserving or curing material that you may have. While they are designed for different users, they both achieve the goal of removing as much moisture from your material. Both machines have advantages and disadvantages, which is why you can’t say one is superior to the other. But with the pros and cons listed for each, you should be able to make an informed decision.