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How to make a food dehydrator yourself

How to Make a Food Dehydrator Yourself?

This is a simple and easy to follow guide How to Make a Food Dehydrator Yourself?

They are very fashionable in our modern kitchens, inspired by an ancestral technique and the solar dryer: food dehydrators are on the rise or rather hot air.

If their principle is straightforward, to slowly dehydrate and dry food, we can then ask: is it possible to manufacture a food dehydrator yourself? Do you have to be a tinkering and DIY whiz, or is it possible to do this just with a few wooden planks or an old drawer or box?

The process of drying food is not that complicated and only requires a closed space in which to place the food and to circulate a bit of hot air there for several hours to remove the water contained in fruits or vegetables, for example.

Of course, electric dehydrators like Excalibur use technology to improve this principle and save time and precision, but let’s try here to explore some ways to make a homemade dehydrator yourself.

homemade dehydrator yourself

The principle of the dehydrator

Let’s start by recalling the basic principle of a food dehydrator. The purpose is to circulate hot air around foods like fruits to release moisture slowly and dehydrate them, thereby preserving them longer, not using freezing and less power consumption, and keeping nutrients. Other benefits of dehydration you can find in our article here.

Generally, we, therefore, speak of a box or a closed container with one or more trays for placing the food and a circulating heat source for the food drying process.

Air circulation is an essential point because the hot air must constantly circulate through the dehydrator, in particular, to avoid condensation.

Suppose hot air naturally circulates from bottom to top. In that case, this drying process sometimes distributes the heat unevenly. It can be less efficient and precise than horizontal air circulation, for example, from edge to edge of the box or the dryer that we will build.

There are vertical and horizontal dehydrators, both types having their advantages and disadvantages.

Two types of heat can be used: heat from the sun, found in the traditional solar dehydrator or solar dryer, or electric heat, located in modern dehydrators inside the house.

Let’s see two ways to make a homemade dehydrator.

two ways to make a homemade dehydrator.
two ways to make a homemade dehydrator.

Build a solar dryer

The first idea for a homemade dehydrator is a DIY solar dryer. Obviously, in Quebec, it will be limited to the summer season since the sun’s rays will be the primary source of energy.

Suppose we simplify the principle, inspired here by what our ancestors were already doing using solar energy, instead of simply letting the tomatoes dry outdoors in the sun on a small tray. You have to make a box around them to protect them from insects and dust, then optimize the circulation of heat and air, possibly by adding a sensor.

We can, therefore, start by building a rectangular wooden box with a few boards, a drill and some screws.

The drawer trick: It is possible to use a drawer to make the primary container of the drying rack and build the box around this drawer to easily slide the interior of the drying rack and replace or move the food by example.

With or without a sensor?

The traditional dryer model includes a heat sensor to optimize heat capture and make the best use of solar energy to heat the air.

It is often an inclined plane, obviously turned towards the side where there is the most sunshine, made up of a black or silver background to capture the maximum heat, and covered with a glass or plastic window. Transparent plastic, with a space of just a few centimeters between the bottom and the window, concentrates the hot air that will rise naturally towards the drying chamber with the food.

Make a window or a door.

Drying with the sun’s rays remains subject to the degree of sunshine, therefore irregular in terms of temperature and consequently drying time: this is why it is essential to regularly check the stage of food dehydration.

Ideally, the top of the box should be transparent, often made with glass or translucent plexiglass, to already see the evolution and control the degree of dryness of the food and accentuate the greenhouse effect created to increase the heat.

The easiest way for this window is to attach a relatively thin transparent plastic panel with staples.

In simple and more minor, sensorless solar dryers, some will choose to tilt the transparent window to catch the sun better, which complicates the box’s design a bit but is still handy, with a bit of patience!

However, some make solar dryers without glass on the top, especially for larger dryers with an angled hot-air sensor, usually providing access to the trays and inside the dryer, such as a door in front or at the bottom rear, which still has the disadvantage of letting out heat when you open the door.

In this case, you will also need some hinges to build this opening. Models often see it as more significant than a simple rectangular box, looking more like a kind of cupboard a little higher, with either several trays inside or several supports to hang or hang the food to be dehydrated.

Interior: optimize heat retention

It is also essential to think about covering the inside of the box with a coating that will retain heat and help maintain a specific temperature.

For example, putting a black liner, why not a black plastic bag fixed with staples on the bottom of the box, or even with black paint to cover the inside of the box.

The good old aluminum technique will also work with good exposure to the sun or a silver surface that reflects the sun’s rays, although it can sometimes heat up quickly.

Ideally, the interior of a dehydrator should be between 40 and 50°C, which is not easy to control in a weather-dependent solar dryer.

Thermometer: Incorporating a thermometer is a good idea to constantly monitor the temperature and check, for example, that you are not too hot, not overcooking the food.

Airflow: vertical or horizontal

However, you also have to think about air circulation: the hot air must come in and out of the box, mainly to avoid condensation since making dried fruits or dried vegetables is to remove the humidity.

Several techniques exist for this, using the principles of vertical or horizontal air circulation as found in commercial electric dehydrators: the vertical ones are often more spacious because more trays will be placed there. The horizontal ones are more efficient at the level of the distribution of heat and the uniformity of the process, sometimes allowing better control of the drying time.

Vertical: If we stick to the principle of our simple wooden box, it will be pretty simple to drill or slit small openings in the box, below so that the hot air enters and above so that it comes out as warm air rises.

Horizontal: To make openings on the sides of the box so that the air circulates there on both sides, it is necessary to use a mesh fine enough for the air to pass but filter insects and flying debris to protect food: a mosquito net is often the ideal and inexpensive solution for DIY ventilation grilles!

If you are a little handier, some buy small round plastic fans, for example, to integrate on each side of the box.

How to make a food dehydrator yourself

Make an indoor dehydrator.

Suppose you do not want to embark on the adventure of the outdoor solar dryer, especially since, in Quebec, you will not be able to use it that much during the year. In that case, it is also possible to make a homemade dehydrator.

One of the most straightforward techniques will be to use the concept of the wooden box, more or less significant depending on the number of trays you want to be able to use, even if some sometimes use other materials with stainless steel or even plastic box.

Wood remains one of the best materials with ideal properties for food dehydration.

It is important to always respect the air circulation principle, with vents on one edge and the other of the container, depending on the size.

What will change here will then be the heat source, which will usually come from underneath the box.

To produce this heat, two solutions, depending on your time, means, configuration, and skills, are either an external source or an integrated source that you will build with the dehydrator.

We will previously choose an electric heat source without fumes, so no gas sources, for example, or with flames.

External heat source: electric food stove, hob, small electric heater, heat bulb, or even an oven: you can use an electric heat source.

The main thing is not to put your box/dehydrator directly in contact with the external heating element but to be able to raise it a little above it, ideally about fifteen centimeters.

Suppose you are using multiple trays in your box/dehydrator. It will be necessary to rotate because as hot air rises, as with any vertical dehydrator, the heat is not evenly distributed.

Also, be careful to have the bottom of your box or container thin enough so that hot air can penetrate and circulate.

Integrated heat source: if you are a little handier, it may be interesting to integrate an electric heat source directly below or inside your DIY dehydrator, which may consist of fixing light bulbs or heating resistors, such as those that can be found in pet stores for heating aquariums or terrariums.

Indeed, these bulbs or resistances are ideal for obtaining a constant temperature without being too high and keeping optimal stability to bring the most dehydrated foods, ideally between 45 and 50° C.

Also, practical, linear type resistors such as spiral wound resistors are ideal since they are often used in commercial devices, allowing good heat stability.

They can be found in some stores or ordered online.

The oven alternative: depending on the type of recipes and food to be dehydrated, and depending on the oven model, the low power of the thermostat, it is quite possible to use your traditional oven to dehydrate food. To learn more, you can read our article on the subject here.

To go further: plans and details.

There are several models and plans of solar dryers or dehydrators to build yourself; by searching the Internet, you can easily find ideas for plans of solar dryers or dehydrators to inspire you or to follow to the nearest centimeter!

Suppose some offer wooden dryers with a significant drying chamber closer to traditional and old solar dryers. In that case, others do not hesitate to provide modern and electric versions equaling some high-end dehydrators!