Making Sun-Dried Tomatoes in a Solar Food Dehydrator

| 11/3/2011 10:22:53 AM

Tags: food dehydrator, drying food, dried food, solar food dryer,

Sun Dried Tomatoes BeginI love all forms of food preservation. I also love reducing my environmental footprint whenever possible. I’ve often thought about the energy involved in canning, freezing and using my electric food dehydrator to save my summer garden harvest for wintertime eats. For me, a solar food dehydrator is the best of both worlds: I can dry food using the free, renewable energy of the sun (unlike the energy needed to boil water for my canner or run my electric food dryer), and my resulting dried food can be stored without any added energy (unlike the frozen foods in my freezer). A solar food dehydrator would allow me to literally save a bit of summer’s sunshine for the short, dark days of winter.

I’ve studied and dreamed about the plans on our site to build a solar food dehydrator for a couple of years now, but I was always stymied by my lack of DIY skills. Luckily, I got the opportunity to try my hand at building a SunWorks Solar Food Dryer Kit. All the pieces came in one large box, I had step-by-step instructions at hand and a short list of other tools (all with names I recognized and could find at home) to help bridge my DIY-skills gap.  

All told, building this solar food dehydrator took me about 5 hours. (Let me be totally honest here: I had never used a staple gun, changed the bits on a drill or used a spline roller before, so it could take someone with these skills already under their belt less time.) I only had minor confusions while reading the instructions, which were easily cleared up by our resident DIY editor, Robin Mather, and Hank Will, Editor-in-Chief of Grit magazine and super-experienced handyman. I still swell up with pride just looking at the completed food dryer, a sentiment many of you DIYers are familiar with, I’m sure.  

Solar Food DehydratorAnxious to test out my handiwork, and hopeful despite the short, cool days we were already experiencing here in mid-October, we set the solar food dehydrator out on Oct. 24, at 10 am. Fellow editor Heidi Hunt and I halved a large bowl of cherry tomatoes (snacking on a few in the process), loaded the dryer racks, tilted the back vent open and left the food dryer facing South toward the sun and warmth. Within only an hour, the food dehydrator reached an internal temperature of 120 degrees Fahrenheit, a high enough temperature to start turning our cherry tomato halves into delicious sun-dried tomatoes. It continued to warm throughout the day, reaching over 140 degrees by 1 pm. The tomatoes were visibly drier at the end of the first day, and by the end of the second day we were well on our way to a successful batch of sun-dried tomatoes. 

The third day, however, rain, clouds and much colder temperatures set in, and by the end of the fourth day (still cold and somewhat overcast), we saw the beginnings of the end: mold spots.

I’m still excited to put our solar food dehydrator to work next summer, when the warmer, longer days with much more direct sunlight will kick our solar food dryer into high gear. Plus, the few bites of nearly sun-dried tomatoes that we snuck throughout the process were well worth the late-season attempt!

10/16/2013 3:33:36 PM

Howard Lee, do you raise the screens? How and how high? Do you place anything under the screens to catch any liquid that might drip? I have never done "drying" so know NOTHING. Thanks.

megan phelps
7/19/2012 7:51:38 PM

This is the coolest project!

6/9/2012 5:53:00 PM

We have been solar dehydrating our produce for a couple years. To assist in the deyhdration process my husband added a small solar panel hooked up to a couple reused computer fans to pull the moisture out of the unit. This cut the time needed in half for some items.

baruch atta
12/12/2011 6:46:32 PM

Howard: in a car, under the hood, you can cook meat or fish on the engine exhaust manifold. Just wrap the food in double aluminum foil.

leatha waldron
11/18/2011 3:01:23 PM

I like that idea Howard.

lynn snyder
11/16/2011 6:21:26 PM

Well, I guess whatever works.... But I've been reading about solar food drying and I've picked up a couple of notions. One, I would want the food to stay relatively cool as it dries (below 110 degrees) so that the enzymes of the food are preserved. Secondly, I would not want direct sunlight to hit the food to also preserve food value. All that's needed to dry food is to have contact with air that's dryer than the food and there are other food dryer designs that emphasize air flow rather than heat: I've tried and liked the screening material sold at for making trays.

k.c. compton
11/7/2011 3:04:26 PM

Love this! I want to build one next summer. A few summers ago I decided to dry carrots in my electric dehydrator. With my what-was-I-thinking cap firmly on, I sliced the carrots on the round and turned on the dehydrator. When I came back home after 8 hours or so at work, I discovered these itty bitty little carrot discs on the dehydrator shelves. They were bursting with flavor, I'll give them that, but were about the size of jumbo confetti. Still -- over baked potatoes, they were sort of fun while they lasted. >:=]

michael paraschos
11/4/2011 3:12:36 PM

put a light bulb in the box for an auxillary heat source. incandesent bulbs give off 90+ percent of their wattage as heat.

sunny garbarino
11/4/2011 1:36:39 PM

Could you have brought them inside and finished them in the oven?

howard lee
11/4/2011 1:03:08 AM

I've got a solar dehydrator that I've been using for years. It's called a car. A few small window screens in the back seat covered with apples or whatever dry out in no time with it parked in the sun.

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