We have a lot of fruit trees that produce far more than we can eat fresh. Preserving with canning or making jam or jelly, or baking heats up the house too much in the summer months when a lot of this fruit becomes ripe. It also takes a lot of time and energy to make jams and jelly. And so a lot of the fruit has normally ended up just falling off the tree, rotting, or otherwise “wasted” (I know, the fruit is not really wasted, just recycled and composted at the base of the tree in the circle of life).
The most simple and elegant way to preserve fresh fruit is to dehydrate it. And free summer sunlight provides the heat to do the job quickly. So I have wanted to build a solar dehydrator for a long time to capture as much of this fruit as possible for eating later in the year. But I have enough ongoing renovation and remodeling projections that I just never found the time to start another new project, especially one that required buying more supplies like plywood sheets. But then I realized I really had a lot of construction scrap and leftover pieces that I might be able to cobble together to make a dehydrator. So this is what I did.
I roughly followed these plants for a solar dehydrator, adjusting its measurements as necessary to match the scrap I had on hand.
I did not have plywood sheets, but I did have long boards that I knew I could cut up and stack together to make the sides of the dehydrator. And the fact that they were already stained black was ideal for the interior of the dehydrator.
Using an carpenters 90°angle square I cut the boards into four equal pieces for the end walls of the dehydrator.
Here is the board cut up and before assembly into the side pieces.
A little scrap 3cm x 5cm wood, glued and screws finished the end piece construction.
To let air flow through the dehydrator, I used a large key hole drill bit to make a series of spaced holes at the base and top of each end wall of the dehydrator.
One of the two completed end pieces.
The end pieces were then glued and screwed together with more scrap wood to form the main box body of the dehydrator. Normally, all the sides are made from plywood. But since I did not want to buy plywood, I just build up the sides as shown with scrap wood.
To protect the box and contents from the rain, I painted the dehydrator with some left over green paint on the outside and black paint on the inside. The dehydrator legs, trays and tray supports were constructed as per the plans from this link with leftover 5cm x 5cm wood for the legs, 3cm x 5cm wood for the tray supports and 2cm x 5cm wood for the trays. This photo shows a newly built tray being test fitted before it is also painted black. The only thing I bought was screen for the trays (I had some already, but not very much and what I did have was used to cover the round end holes at each end of the dehydrator box to keep out flies).
The plans called for building a lid, but I decided to make it more simple and just used a short length of nylon rope and a bungee cord (both I already had) to attach the plastic cover. The plastic was also a leftover item that wrapped some larger appliance delivery we had recently.
It takes about three days to dry a cherry. And the dried cherry should keep for months. And dried cherries have all their original sugar content, are sweet and delicious to eat. Almost as good as the fresh cherry.
Just about anything can be dried in this dehydrator. The half tray in the lower left is finished with dried white mulberries while the rest of the trays are fresh white mulberries just put into the dryer.
Except for the tray screen, everything I used to build this unit was from scrap or hardware I already had on hand. And I am very pleased with the results of this solar dehydrator. The only work I have is to harvest the fruit, cut larger ones up as needed to quicken the dehydrating process or to remove pits. All other work in dehydrating the dehydrator does passively on its own. I expect this unit to be in near constant use all summer as our various fruit trees start to ripen one after another from now through September. I will also try dehydrating tomatoes once some of mine ripen.
A passive solar dehydrator is definitely a tool anyone with a garden or fruit tress should consider having.