So you have decided that you’d like to be able to make your own jerky, fruit leather, vegetable chips etc and have decided to buy a food dehydrator! Now, what one to get? There are various different brands and types on the market and in this guide we break down the technology and the features and explain exactly how they work so that you can figure out the best kind for your individual needs.
Air Flow – Horizontal vs Vertical
Most dehydrators are fan operated which means that a fan circulates the air around the unit which dries the contents. There are two common types: horizontal and vertical and as well as the mechanical differences in the way that they operate, they also affect the actual end result.
In a horizontal system there is a fan mounted at the back of the unit and this will distribute the heat evenly across each of the trays. This allows for a uniform level of heat across each tray and across all the trays in general. These types also tend to generate more heat in general than the vertical ones, which makes them more suitable for drying more robust items such as meat and chicken.
The vertical systems have a fan mounted either at the top or the bottom. They are usually at the bottom and the heat flows up through the trays. The problem with these types is that there is usually more heat on the lower trays than the bottom ones and to ensure even drying you generally need to spend some time rotating the trays around.
There is another type of drying method and that is the use of convection heat. Instead of using a fan to blow hot air onto the food, they instead have a heating element in the bottom of the unit that allows the heat to rise naturally upwards through the trays. The upside of this method is that they use less electricity and are much quieter (no noisy fan) but the down side is that they can take much longer to dry foods and for those living in humid climates, longer still.
Stackable vs Rigid Box Units
Many of the vertical air flow dehydrators are stackable and what this means is that you can purchase extra drying trays which stack on top of existing ones to give you more space. This sounds awesome but there are some drawbacks.
Firstly, if the dehydrator has a standard fan mounted at the bottom of the unit, due to the way the air flows from the bottom up as we described above, those trays at the top of the unit are going to take much longer to dry than the ones at the bottom that are nearest the heat source. You will need to regularly rotate the trays for even drying.
Also, the stackable trays are of a fixed height, very often around 1 inch tall. This is fine for items such as slices of vegetables or small fruits but if trying to dry larger or thicker items like larger fruits, chunks of meat, proving dough etc, you will not be able to fit these items on those kinds of slim trays.
With a rigid box system you cannot alter the size of the unit. The box will be fixed and have a fixed fan system in place to distribute the heat over the contents. These units come with shelves rather than trays and you can usually remove some shelves if you need more space for larger items.
These kinds of units use the horizontal air flow system described earlier and are generally much more efficient at drying and will allow you to dry larger, robust items like meat for jerky with much more efficiency than the stackable units.
You can also leave them unattended for long periods of time without having to mess around with the trays which is very convenient if you want to be able to setup the dryer and then leave the house for a while.
Drying Capacity, Time & Power
How much do you want to be able to dry at once? In fixed units (whether stackable or rigid box) you cannot increase the capacity in any way so you are limited in how much you can dry at one time. If you need to dry large quantities at once due to large crop harvests for instance, a larger capacity unit may be needed.
You should also consider the drying time. Smaller units are often less efficient and will take much longer to dry the same amount than one of the larger units. Again, this is usually not an issue unless you really need to dehydrate a lot of food in a short space of time.
Lastly, the power usage can vary greatly. If all you are doing is drying out a few herbs then you really don’t need much power and a compact and economical dehydrator will probably be fine. But if you’re wanting to dry out very moist items such as meat or large water-rich fruits and vegetables then you’ll need more power.
Making jerky is probably one of the most common uses for a home food dehydrator and for that you’ll want a unit that can run at at least 160 degrees Farenheight / 70 degrees Celsius.
Footprint (Counter Space)
If you are using the dehydrator for home use which most of our readers will be, you’ll probably need to consider the physical footprint of the machine. If you have a small kitchen and limited counter space, then a large rigid box unit may simply be far too big for your available space.
This is where stackable units can be very useful because you can add more trays vertically allowing you to dry more at once without actually taking up more footprint space. But of course, remember to investigate the air flow system used and see whether or you will need to rotate the trays around when using a particular stacking system.
Now that you know the basics of the dehydration technology and have decided on the kind of machine you need to buy, you can start looking at additional features that can be useful:
This is really a must for most people. As mentioned earlier in this guide, thicker and more robust items such as dense fruits or meats will need a much higher temperature than something delicate such as herbs. Being able to adjust the temperature according to what you are drying will give you much better results.
If you know that the drying is going to take a long time and you want to be able to just leave it to do it’s thing whilst you go and do yours, then you’ll need this feature. It will allow you to leave it overnight, or for the whole day while you go to work and come back and know that the drying is complete. Of course, this is more useful on the kinds of units where you will not need to be swapping the trays around.
One of the rather trendy things to use a dehydrator for these days is making fruit leather. This is where you make a fruit puree and then dry it on sheets until it has a leather-like consistency. Very popular with the kids! To do this you will need special non-stick mats that you can pour the puree onto, so not everybody will need them. Some manufacturers will produce these as an accessory that you can buy.
The main points to consider are what kinds of food do you want to dry, do you need to leave the dehydrator unattended for long periods of time or are you okay with some tray swapping shenanigans, and how much food do you want to dry at once? These main considerations will tell you what basic kind of unit you need, and from there you can look at the extra features to refine your selection.