How Does a Food Dehydrator Work?

​Ever wonder how a food dehydrators works?

…in simple words, dehydrator produces the heat and removes the water content in the food item.

Dehydrators are very simple appliance which contains few items with the help of that it does it’s job (removal of water from food item). It’s very easy to understand. 

Let’s start with the Dehydrator Basics…

As I told earlier, A food dehydrator is an appliance that is used for drying food item like vegetables and fruits with the process of dehydration.

Dehydration is a method of food preservation that eliminates moisture from the food so that it can last longer. Due to the absence of moisture, the bacterial growth gets reduced which also leads to the avoidance of spoilage.

​However, the dehydration procedure makes the food items loose its original size, shape, weight and weight but it does not influence its nutritious content.

You might be wondering:​

how does a food dehydrator work? So, below in this article we are giving you the details regarding the working of food dehydrator along with the origin of this appliance.

​Origins of Food Dehydrator:

The technique of food preservation has been followed by the ancient time period when the food was left in outside in the blazing sun to dehydrate.

The procedure at that time might have possessed a little health as well as cleanliness issues but still, it worked amazingly.

Though, after some years inventive thinkers made some improvisation in this method of dehydrating foods with a procedure that is quicker, harmless, and effective. This is how the origin of a food dehydrator happens.

​In a food dehydrator, the combination of heat, as well as the movement of air, is used to dry foods.

A regular food dehydrator comprises of shelves which have open segments that allow circulation of heat and air along with a hygienic manner of handling and shielding the food. The pre-set temperature of this appliance allows the uniform drying of the foodstuffs.

The ​Working Process of a Food Dehydrator:

How does a Food Dehydrator Works

​In order to understand that how a food dehydration appliance works, you first need to know about its components which formed food dehydrator.

One of the main elements of this appliance is heat which is required for drying out the food items. Besides heat, the other significant parts are regulatorstraysfans, as well as air vents.

Every single part has its role and unanimously sum up to perform effectively as a food dehydrator.

So, below, we will break down the functions of these parts along with the complete internal mechanisms of the appliance.

1. Setting the Temperature – Where we tell dehydrator to how food has to be dry

temperature setting in food dehydrator

​The main step is the setting of the temperature in a food dehydrator as per the category of the food that you want to dry out.

It is very difficult to set an accurate temperature, but due to the presence of regulators you can do it easily.

A temperature regulator helps in adjusting the amount of heat that needs to be generated for the uniform drying of food and also for setting the speed at which the fans will work.

The guidebook that is provided along with the appliance guides you a lot regarding the temperature setting. So, you can also consult manual book which comes with the dehydrators for better understanding of temperature setting for each kind of food items. 

2. Place the food on the trays– Just arrangement of food on dehydrator trays for better drying

place food on food dehydrator trays

​The trays possess an exceptional design which allows them to be arranged in numerous ways in order to provide proper air circulation.

The food which requires more heat can be placed near the heating element and the foods which are delicate can be placed on the tray which is far from the heat source (Note: this is not applicable for all dehydrators).

This feature is not available in every appliance as several food dehydrators offer uniform drying and you cannot place two types of food at the single point of time. There are few units that also comprise of circular trays which rotate automatically during the process.

3. Releasing of Heat-Different dehydrators uses different ways to release heat in dehydrator

dehydrator heat and air distribution

​The next step is the release of heat through the heating element so that the moisture content of the food can be eliminated.

This might take few minutes to few hours. It completely based on food items or sometimes based on the dehydrator capacity. 

The construction of the dehydration unit as well as the trays is done in such a manner that food does not get burnt easily during the dehydration.

Some units contain transparent lid at the top/front/side so that you can check the status of the food and few of the appliances have inbuilt timers that turn off the dehydrators when the process completes.

4. Flow of Air – How heat and air is distributed inside the dehydrator. Place a major role in how well all the items dried inside the dehydrator

​I think I could have combined this step with the heat flow step itself, I guess. But still I kept this as a another point itself.

The air fans are situated either at the back or top of the appliance so that it can direct the movement of heat as well as the air inside the unit. This also benefits in regulating the temperatures at a preferred level. The fan blows the heat inside the appliance so that the food can lose the moisture which can also be sent out through the air vents.

Full working of Food Dehydrator:

​As a whole, Food dehydrator consist of few items as mentioned above to form a fully working dehydrator machine. 

In simple sentence… Dehydrator Trays hold all the food items which we need to dehydrate. A heater inside dehydrator generates heats, Fan inside the dehydrator circulates the even distribution of heat as well as air, which finally helps in removing of water content in the food items.​

Thermostats & timer is a like a optional unit in a dehydrator. Lower end dehydrator doesn’t comes with those option, but still you can use the dehydrator to dehydrate the food item without any issues.

On the other hand:​

You are going to lose little control over your dehydrator without thermostat and timer. If budget is not an issue, I recommend you to go with both options. ​


All the above steps shows that how a food dehydrator works for drying out the food items uniformly. Different types of dehydrators are available in the market which possesses varied features, for example, some of them have heating elements on the side walls instead of top or bottom so that fast dehydration can be performed.

But still, the working criteria of all the kinds of branded food dehydrators is similar and the ultimate outcome is the proper drying out of the food so that you can enjoy your food in a healthy and nutritious way.

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Hi there, I’m Linda, chief editor at Dehydrator Blog. We believe in Health is wealth. After struggling to buy healthy organic food for my family, I decided that’s not the right way to do. Still today many of them not aware of food dehydrators and uses of dehydrated food. That’s why my team and I want to solve this problem. That’s how Dehydrator Blog was born.. Our mission is simple. Trying to spread awareness of dehydrator to all. Join our hands if you believe in our mission.

Adnan Jaber - October 17, 2019

Dear Linda

Good job Linda

Kindly, I read your topic and your notes above, however, I have a question, when we use the dehydrator for example for dates, what is the least percentage of humidity remains in the dates or in the fruit in general; is it 1% maximum or below or above? I am asking because there is no reference to this point in the topic.

Your feedback is so much appreciated

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