Test Drive of a Solar Food Dryer

solar dried tomatoes

dried apples

I attended a totally awesome solar cooker festival the weekend before last in Sacramento. Building a solar cooker now tops my to-do list, but I haven’t had a chance to even look at plans, much less build one. However, I did discover that we have a solar cooker and a solar food dryer here at the community! Our manager, Chidambar, dug out the solar dryer, which he built (it’s wonderful!) and lent it to me. I’ve been having a blast testing it out this week. I dried apple rings first.

apples in dehyrator

The solar dryer works extremely well. It’s basically a wooden box topped with a glass window pane, with a hinged opening on the back, the whole thing raised on four legs. Inside the box sit two horizontal screens, which you can easily pull in and out of the back of the box. Under the screens sits a matte black piece of thin metal. A piece of wood covers most of the outside bottom, with a four-inch wide opening across one end, protected with window screening. That gap plus two small vents on the side help keep the temperature at an ideal range for dehydrating—and not cooking—food. I was amazed when I first noticed this baby had reached a temperature of 175ºF.

Now, I realize not everyone has a solar food dryer kicking around. If you want to build one, you’ll find many excellent plans online. Or, if you have a pilot light in your oven, or turn the heat on very low, these should turn out well (I haven’t tried that though).

apples and lemons

Ingredients

  • 6 medium apples
  • 3 medium lemons (I can count; I just needed a third after I took the pic)
  • water

Directions

apple slices1. Core apples and cut into 1/4″ slices.

submerge apples2. Combine 1 part lemon juice with 4 parts water. Submerge the apple slices in the solution for 10 minutes. If the apples bob up to the surface, weigh them down with a plate. Apparently, fruit can lose color and flavor if you do not pretreat it before dehydrating it. I wish I had tested this by drying some slices I hadn’t treated. Next time…

sliced apples3. Remove the apple slices and allow them to dry for 10 minutes.

apple thief

4. Arrange the apples in the dehydrator so that no slices touch each other, allowing the air to circulate. Place the dehydrator in the optimal position for catching the sun’s direct rays. You’ll have to adjust it every once in a while as the day progresses. I turned it a few inches every hour or two.

These shrink so much, I thought someone must have been eating them, they looked so sparse after just a few hours. I did catch one thief!

drying apple collage
Different stages of drying over the course of a day and a half

These dried apples are delicious—very sweet and chewy. Before this past Sunday, I had not seen apples at my farmer’s market. Ideally, when the market overflows with apples and the price plummets later in the season, I would dry a barrel or two of them, dehydrate them and store them in glass containers through the winter. They make a nice addition to trail mix, steel-cut oats or muffins. Apparently they keep for a year, but we ate this first batch.

This recipe is about as close to zero-waste as I can get. The lemons came from the yard, the apples, from the farmer’s market in one of my homemade cloth produce bags and the energy, from the sun.

20 Comment

  1. That’s awesome! How tasty and energy efficient and a great way to use a glut of apples!

    1. Thank you 🙂 In a couple of weeks I hope to dry many pounds of tomatoes when the farmer’s market stalls are bursting with them.

  2. chris says: Reply

    This seems so great! Do you think it would work just as well with other fruits, like plums or strawberries? Not that I have a solar food dryer anyway, but I think I’d be willing to invest some time making one if I could dry a bunch of different fruits. It’d be such a healthy snack! Thanks for sharing your experiments 🙂

    1. You’re welcome. Thanks for the comment 🙂

      It’s supposed to work for all sorts of fruits and vegetables. Apples seemed like the easiest thing to start with. I would also like to try herbs. I imagine it would be good for drying homemade pasta too. This site has some good recipes and tips: http://solarfooddehydrators.com/food-dehydrator-recipes-tips/

  3. They look great!

    1. Thank you! They were tasty 🙂

  4. Malar says: Reply

    Solar dryer, that is too good!! what a great way to save electricity and use the solar energy!!!

    1. It’s pretty cool. I have all this work to do today but I want to play around with the food dehydrator instead 🙁

  5. solar dryer sounds good and dried apple from dryer looks perfect and delicious. …

    1. Thank you! I’m looking forward to trying all sorts of experiments with the dryer.

  6. Dehydrators are quite trendy here at the moment, but they eat so much power I could never justify having one. A solar dehydrator makes perfect sense! I would love to make one. Another thing to add to the wish list : )

    1. I hesitate to buy any new gadgets or appliances, as they don’t seem to last long. This dehydrator can’t really break down though (unless termites get at it, in which case, it could be repaired). And I love, love, love that it uses zero electricity! I hope to make one too. This one is on loan and I suppose I will have to return it eventually 🙁

  7. Solar dryer sounds interesting and those apples are perfectly made:-)

    1. Thank you! It’s been fun trying different foods in it.

  8. Hilda says: Reply

    Thanks for posting this design. I have used the dashboard of a car, which works pretty well, but this looks a lot more reliable. And yes, now I have learned to dehydrate tomatoes, it is by far the best way to preserve them.

    1. You’re welcome. Holy cow, you made a dehydrator using a dashboard?! That’s impressive! I tried tomatoes also and they tasted incredible. I would like to get about 25 or 30 pounds from the market over the next couple of weeks for the dehydrator. Do you store yours dry? In oil? And what do you cook with them? You have such great ideas 🙂

  9. That’s fantastic! What a great way to dehydrate fruits without using electricity. Thanks for sharing!

    1. You’re welcome. I’m having so much fun experimenting with it. Thank you for checking out my post 🙂

  10. nice..they do it here but don’t know how..thanks for sharing. I do have a solar cooker..I don’t use it now as it has to be moved with the sun..and I am at work. My mum used it though..

    1. That’s so awesome, Jasmin. I love these ovens. Some of them do have to be moved often. I’m building a solar oven for a solar cooker festival I hope to participate in this July. Mine will be a box cooker and I plan to set that inside a parabola of tinfoil covered cardboard. The box cookers apparently require less moving around especially with reflectors or a parabola like I hope to make. I will write a post about my oven eventually…

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