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Do it Yourself Dehydrating
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Written by Dave Gillen
THE THEORY ABOUT DEHYDRATING
Drying food may make it light to pack but there's alot more to it than you might think. Nature has a way of dealing with food that goes unused for any length of time.
The Spoilage Triangle
Spoilage may look and smell ugly but it is nature's way of bringing the unused nutrients
back to the earth to be used again. Spoiled foods are in a state of being broken down by
micro-organisms, much like a composter. So long as these micro-munchers have enough air,
heat, and water, they will carry out their appointed duties.
Any method of preserving food breaks one of the corners away from the spoilage triangle.
So long as any one of the three are removed then spoilage can not quickly occur.
Freezing food takes away the heat from the triangle. Canning or preserving helps to kill most of the bacteria and also removes most of the air from the food. This also breaks the triangle.
Drying is another way to break the triangle. It is probably the least used method today
but at one time it was the ONLY way that you could preserve food. Natives used wood smoking
to dry fish and other mixes. Smoking meats imparts the flavor of the wood used in drying
into the food. Hickory and applewood are my two favorites for smoke drying. There are few
things tastier than smoke dried trout or beef jerky!
Dehydrating food is another form of drying that removes the water from the food using air
and low heat but does not add any additional flavor to the food. Flavor can be added
before drying to enhance the taste of the final product.
BUILDING YOUR OWN DEHYDRATOR
There's no secret on how a dehydrator works. Supply some warm air, some openings for
the air to flow in and out, a container to do it all in and voila! A dehydrator!
You've probably seen them advertised on television or seen them on the shelves at your local
discount retail store but whether you buy or build the results are always the same.
The Home Made Dehydrator
Here's the starting point for building your own dehydrator. The images are a little rough
but I'm working on new graphics for the future. As always you should check back often.
Dehydrator Dimensions
The size of the dehydrator shown below is roughly 24 inches wide by 20 in height. The
depth is roughly 18 inches. I made mine rather big because I was always dehydrating for
larger groups and this reduced my batches. The material used in the construction was 1/2" plywood.
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FIGURE 1 (Front View) 
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Figure 1 shows the dehydrator with the front door removed.
The heart of a dehydrator is it's heat source.
The dehydrator shown uses lightbulbs for the heat. They
should be covered over the top with a piece of sheet metal to prevent any of the food
from dripping onto the bulbs. You'll have to experiment with the size and number
of bulbs until you achieve an internal temperature around 130 to 140 deg F.
You'll also notice that there are openings in both the top and bottom of the dehydrator.
The bottom vents allow fresh dry air to enter and the top vent allows the moisture to escape.
A little experimentation can be done on the size of the openings. My dehydrator has
adjustable vent covers to adjust the air flow and keep the internal temperature correct.
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FIGURE 2 (Top View) 
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The trays were constructed from 2 inch trim and stapled at the ends.
The screening that the food rests on was made from plastic door screening stretched and
stapled to the frame.
The tray hangers can be simple nails or screws driven into the inside walls. I bought some
plastic 90 deg. edging from a hardware store and screwed that in as the hangers.
Notice that the trays are slightly less deep than the dehydrator itself. This allows for free
air movement within the dehydrator.
The front door is hinged on the bottom. I used a magnetic catch on the top but any type of holding system
will do the trick.
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Other Ideas
After some experimenting I installed a small fan installed inside the dehydrator to help
circulate the air. This improved the drying. Some areas in the dehydrator seemed to dry
better than others and this corrected the problem.
