I'm going to break from fiber crafts this time, and write about something new we tried last week. We made some cheap homemade solar ovens and cooked our first 100% sun-baked dish! It was really fun! This was, in part, for an Earth Science homeschool lesson. What better way to study the sun, than with a hands-on activity like this one? I also see this as a great emergency prep option, for when the power goes out, in our hurricane-prone area.

Our first attempt didn't work out very well. We did the
pizza box solar oven on Tuesday, but only got so-so results (that oven only got up to about 175 F for us, though the designers on YouTube said it could get in the 200's F. But we noticed there was an open hole at the bottom back of the lid when the pizza box was closed, so there's one place where we could improve on the design so heat won't escape. We baked pizza for this one (what else?)... first the crust by itself, then later added the toppings (I used the pizza recipe from
New Vegetarian Epicure). The crust was still a little doughy by the time the sun started going down, so I finished it off in the conventional oven just to be safe, especially when I saw the temps starting to dip towards 150 F.) The pizza did taste good-- I just wish it could've finished up in the solar oven. I'd like to try cookies in this oven next, after we get the hole on the lid patched up. So I haven't given up on it yet!

While our first attempt sorta bombed, our second attempt went great! We had much better luck with the aluminum roasting pan solar oven (see
solarcookingnuts's videos on YouTube... there are 3 videos with tips, just for this design.) I adapted a favorite cornbread stuffing recipe for use in it. The oven got up to 220 F at its highest, though it may have gone up even higher if the roasting bag hadn't come loose at one point when I went to shift the oven back into the direct sunlight... I lost a lot of heat then, but it quickly rebounded back up to 220 F within a half hour, during the peak time of the day. If I remember right, the video said this kind of oven could get to 250+ F. We used a glass
2 qt. round Pyrex baking dish inside the oven, the bottom of which we painted black with
Folk Art Enamels Acrylic Paint (non-toxic paint from A. C. Moore). We left the lid unpainted so we could see inside. We looked all over town for suitable black pots, and they were either too expensive or too big for this size oven, so the Pyrex was a good solution (some cook in mason jars, painted black, too). We put black tiles on the bottom of the oven, just like the video said, to help absorb and hold heat, and we used a little baking rack on top of the tiles to elevate the baking dish for even heating (the
meat rack I used was the little round one that the Rival Crockpot people sell for their crockpots). From start to finish, the recipe took 6 hours to sun-bake. The stuffing was nicely browned on top, and there were absolutely no scorched areas at the bottom of the baking dish!

If you want to try this, watch those videos first. In fact, there are quite a few solar cooking videos on YouTube. Also, be sure to use an oven thermometer in the solar oven, and make sure food temps stay above the "danger zone" (i.e. between 40 F- 140 F... bacteria proliferate in this range). Another useful temp to remember: water boils at 212 F (remember that from your science days?) A solar cooker can be a pasteurizer, too. Heating water to about 150º F is sufficient to kill coliform bacteria, rotaviruses, enteroviruses and even Giardia. (For best pasteurizing results, heat to 160º F for at least six minutes.) Also, for safety: always wear sunglasses when working around a solar oven. Always approach the oven from the side or back (never from the front!) to reduce the chances of direct reflections scorching your retinas (yes, this is a real danger). And turn the oven out of the direct path of the sun if/when you have to stir the pot or add ingredients (generally speaking, you don't have to stir solar cooked food... treat it much the same as a crockpot, and expect temps to dip big time if you do open the lid). And of course, your pot will be hot, so use gloves or pot holders. Oh, and if you have to paint any part of the oven or cooking pot black, be sure to use one that says "Non-toxic when dry."
Here's the recipe we used:
Cornbread Stuffing by Curtis Aikens (this is my adaptation for solar cooking)
4 c crumbled cornbread (we used the
Moosewood Cookbook cornbread recipe... use your favorite)
2 c breadcrumbs (from homemade whole wheat bread)
2 c vegetable stock
3 celery stalks (including leaves), finely chopped
1 medium onion, finely chopped
2 large eggs, beaten
½ stick butter
1 t dried sage
Salt & pepper, to taste
Step 1: Place vegetable stock, celery & onion into a covered glass baking dish (bottom painted black). Solar-bake approximately 2 hours between 175-195 F.
Step 2: Add the cornbread, breadcrumbs, eggs, butter, sage & salt & pepper. Solar-bake for 4.5 hours, or until the dressing is set and nicely browned.
This was how the times/temps played out while baking the above:
10:45 AM: below 150 F inside oven-- 73 F outdoor temp -- We didn't preheat the oven first. We just put Step 1 in immediately (most people preheat first for 1/2 hour or so).
11:25 AM: 175 F inside oven--- 76 F outdoor temp
11:45 AM: 180 F inside oven -- 83 F outdoor temp
12:35 PM: 185 F inside oven -- 86 F outdoor temp
1:00 PM: dropped below 150 F because I added Step 2 of the recipe at this point -- 89 F outdoor temp
1:15 PM: 180 F inside oven -- 89 F outdoor temp
2:00 PM 190 F inside oven -- 90 F outdoor temp
2:40 PM: 160 F inside oven due to moving the oven and accidentally causing the plastic cover to come off -- 98 F outdoor temp
3:10 PM: 150 F inside oven due to shade moving over oven -- 103 F outdoor temp
3:45 PM: 220 F inside oven! 88 F outdoor temp (it must have been the peak sun time, because I really had a temp rebound here)
4:25 PM: 205 F, with the sun starting to go down, oven temps also started going down, though the oven was still in full sun. 83 F outdoor temp
4:50 PM: 150 F inside oven. 82 F outdoor temp. Stuffing was nicely browned at this point, and since the sun was going down, I brought it inside and called it done.
Verdict: the stuffing was yummy! The kids liked it, too. I see great potential in these solar ovens as an emergency prep option.
We plan to make either the
BYU Funnel Solar Cooker or its improved design,
Fun-Panel Cooker next.
Some other useful links:
Solar Cooker on Wikipedia (gives a nice overview of the different types of solar cookers)
Solar Cooking (an email list on Yahoo Groups)
Safe Food Handling by the USDASolar Cooking Recipes
Solar Cooking Archive