How to Make a Solar Dehydrator

With a homemade solar dehydrator, you can make delicious, nutritious sun-dried foods.

A solar dehydrator harnesses the power of the sun to dry food. Removing the moisture from food stops bacteria, yeast or mold spoiling it. Not only does drying food make it last longer, it can improve the flavor. Fruits and vegetables that are bland in their raw state can taste much better once they are dried. Dried foods are healthy, tasty and convenient. You can eat them as snacks by themselves, or add them to your recipes. A homemade solar dehydrator can be built from readily available items and can cost next to nothing.

Things You'll Need

• Two cardboard boxes (one long and flat, the other taller and more square)
• Clear plastic film
• Fabric
• Clothes pins
• Non-toxic black poster paint
• Duct tape
• Box cutter
• Ruler
• Chair, stool or low table for support

Instructions

1. 

   The box for the collector should be long and flat.

   Remove one side from the longer box. This box will form the collector for your solar dehydrator. Make sure the part you cut away is one of the largest sides, because the collector needs as big a surface area as possible. (Retain the cardboard you've cut away as you will need it later.) Cut three or four large holes in each end of the box. Paint the inside of the collector black with the poster color. The black paint will absorb heat and make the collector work more efficiently. Cut a piece of clear plastic film big enough to cover the collector and tape it into place over the open side.

2. 

   Remove the top from the other box. This will become your drying box. Measure the width of your collector box. Cut along the bottom edge on one side of the box, then cut up either side of this cut. These cuts should be about the same length as the depth of the collector. You should be left with a flap of cardboard near the bottom of the box.

3. Tape the bottom of the collector box to the bottom of the dryer box, with the holes in the collector box facing the hole you've cut in the dryer box. Tape the collector box onto the dryer box at an angle, so the bottom edges are together but the tops are apart.

4. Cut two triangles from the spare cardboard. They should be about as tall as your collector box is deep. Tape these over the triangular gaps between the collector and the dryer. Tape the flap in the dryer box over the top of the gap. Air should pass freely between the boxes.

5. Cut a piece of fabric large enough to cover the top of the drying box. Place the drying box on the stool or table so that it is supported with the end of the collector resting on the ground. You may want to adjust the position by placing something underneath either the drying box or the collector.

6. 

   Sliced fruits can be dried in a dehydrator.

   Place the food to be dried inside the drying box. Cover the drying box with the fabric. On breezy days, you may want to secure the fabric with clothes pins.

Tips & Warnings

• Foods will dry fastest if you peel and slice them thinly. They will still dry if the peel is left on, but they'll take longer. Foods are dried when you can cut them without any moisture coming out.

• You can make fruit jerky by drying fruit pulp.

• You may want to improve the efficiency of your solar dehydrator by insulating it.

• Vegetables need to be pre-treated before drying or they will not be preserved effectively. Steam blanching and water blanching are both good ways to pre-treat vegetables.

• Store dried foods in small quantities, and check regularly for signs of spoiling.

References

• The Farm: Solar Food Dehydrator
• Scribd: Technologies Demonstrated at Echo: The Solar Dehydrator

Resources

• Mother Earth News: Build a Solar Food Dehydrator