It’s been a busy and long weekend of solar cooking. I have many posts in the works but to tide you over, here’s a quick snack that is easy to make in your solar oven: Roasted chickpeas (aka garbanzo beans).
I start with dried chickpeas because they are the most cost and space efficient. (Obviously skip this step if you are starting with canned chickpeas.) Soak a few handfuls of them overnight in water (probably ended up about 1-1.5 cups of dried chickpeas). Drain the water and then cover chickpeas with an inch or so of new water. Cook in the solar oven until tender (took me about 2 hours) and drain. (Cooked chickpeas could be refrigerated at this point.)
Arrange the cooked chickpeas in a single layer on a cookie sheet like this:
Drizzle with olive oil and a sprinkling of salt and other seasonings. This day, I used a combination of curry powder and garam masala. Shake the tray a little to coat all of the chickpeas with oil and seasonings.
Place the tray in the solar oven and roast about an hour until they are golden brown and crispy on the outside, but still soft on the inside. They’ll look like this:
My tray fit about 2 cups of cooked chickpeas that are good for eating as a snack with a nice cold beverage! Note, I tried to store these in an airtight container for future use and they lost all of their crispiness, so I would not recommend storing these. However, in trying to restore their crispiness, I put them back in the tray after cooking a few slices of bacon and they almost fried in the bacon fat which made these taste almost like nuts, so don’t be shy with that olive oil (or whatever fat you choose)!
Thanks to everyone who stopped by our Maker Faire booth this weekend, especially those young whippersnappers who were able to educate me about how microcontrollers work (turns out they were not interested in the Boris sticker I had to offer but the actual BeagleBone Black! Who says the US is falling behind in STEM education?!).
We also had some great conversations about solar cooking/ovens, solar education, crowdsourcing, manufacturing, open source hardware, and of course, the genius of the Solrmatic. Here are some of my favorite comments:
If you have found this blog because you took a picture of our sign or took one of our cards but did not have time to talk with us, please check out our previous posts about solar cooking and the Solrmatic, which will likely answer most of your questions; but of course if that doesn’t do the trick, please leave us a comment (way, way) below or email us at info(at)solrmatic.com.
Thanks, Maker Media, for organizing this event! Maker Faire gave us new ideas for improvements in design, tests to be run, and new recipes to try, which once completed you’ll read about first on this blog, so stay tuned.
All talked out now…
The much anticipated text message alerts are now incorporated as an exclusive feature of the Solrmatic 2000!
Home solar cooks don’t really need taste testers because their market is so small and usually a pretty captive audience. But restaurant chefs trying to please the masses — or at least a few strangers — probably rely on some outside feedback more routinely. Likewise, if the Solrmatic is going to make it big, we need to make sure that it is useable and functional by other people besides us.
Meet Rick. To say that Rick is knowledgeable about solar cooking would be an understatement…he literally (co-)wrote the book on it! He also has an identical solar oven which improves the scientific rigor of our testing. So he is the perfect beta tester and conveniently lives very close by in case any technical support was needed. Here are his thoughts on his Solrmatic 1000 trial:
by Rick, guest blogger
Like most solar chefs, I’ve come to rely on experience and intuition to estimate how long it will take food to cook in my solar cooker. Every day is a little different, every oven is a little different, and every dish is a little different. There’s a lot of uncertainty involved, but after a while you get a feel for it.
Friends Belinda and Mike may have found a way to introduce some precision and certainty into solar cooking. When they offered me a chance to play with their solar oven controller, I jumped at it. It’s a computer-based control system that automatically rotates the oven to modulate the oven temperature, and it promises to open the door to a level of automation and control hitherto unknown in the world of solar cooking. Mike invented it, and he’s already built a second generation version with battery power and a solar voltaic charger. For my evaluation, he lent me his first prototype, the Solrmatic. With no on-board batteries, I had to plug the unit in to power its electronics and the stepper motor used to rotate the oven.
I can’t deny a bit of initial skepticism. One of the charms of solar cooking is its low-tech nature—what I like to call “appropriate technology.” A dark pot, a transparent heat shield to let the sunlight in, and (for a box cooker) some insulation—and it just works. But there are times when food can get overdone, which can ruin a meal, or underdone, which can lead to microbial food safety issues. True, after decades of low-tech solar cooking, I’ve never had an incident of food poisoning. But you never know.
Having set up my Sport Solar Oven and plugged everything in, I was ready to start cooking. On the Solrmatic, I set the cooking time for maximum duration, ending time for 18:00 (6 p.m.), and desired food temperature to 249F.
I moved the Solrmatic control switch from Setup to Run, and the oven automatically rotated to where it thought the sun would be, given the time of day and its knowledge of longitude. I calibrated it by rotating the base of the Solrmatic until the oven was dead on to the sun, and let the electronics manage the oven rotation from then on.
What to cook? I had bananas and nuts, and thought I’d whip up some banana bread. Oops. No eggs. But then I found a scones recipe that needed no egg. I threw it together and put in some blueberries and coconut (hey, why not?). I stuck the food temperature probe into the batter and closed the lid.
The recipe called for preheating the oven to 425F, so perhaps these scones weren’t really the best choice for solar cooking. But it was a sunny day, and already 1 p.m., so definitely worth a try. Besides, the main goal was to test the Solrmatic, and it didn’t matter much what I put in the oven.
One fun thing about the Solrmatic is that it can connect to your local wifi network and broadcast data to an internet site so you can monitor your oven temperatures from anywhere you have internet access. Here are curves for food and oven temperature for the whole afternoon.
At (1), the oven had been sitting in the sun while I set up the wifi link and whipped up the scone batter. Oven temperature had reached 237F, and the food temp probe was recording ambient temperature outside the oven (84F). The scones went in just after 1 p.m. (2). After an hour (2 p.m.), food temperature had reached 206. I figured it must be done, and I took it out (3).
The result of cooking at this lower temperature was a cakey scone, nicely browned. In the interests of science, I had to taste one with butter right away, but it was even better served as strawberry shortcake for dessert at dinner with a dollop of Greek yoghurt and a drizzle of vanilla.
The Main Course
Okay, so everything seemed to be working. Now, what to make for a dinner main course? It was 2 p.m., with plenty of sun left to cook, provided I could get the food into the oven soon. I had almost everything I needed to make lasagna, so I went for it, using the recipe from Cooking With Sunshine. In this recipe, you water down the sauce a bit and layer the noodles in without boiling them first—it’s a solar cooking classic. By the time I had run to the store to get the few missing ingredients and assembled everything, it was after 3 p.m., so I tilted the oven to its low-sun configuration and put the lasagna in at 3:10 p.m. (4).
I left the oven to do its thing and went about some other activities, checking the temperatures every once in a while. I noted an unexplained dip in food temperature around 3:54 p.m. (5). Since I wasn’t there to witness it, I can only speculate on what caused it. It could have been a cloud passing before the sun, but I hadn’t seen a cloud in the California sky all afternoon. I had set the food temperature to 249F, but, since the food temp at the time was only 68F, I didn’t think the Solrmatic had rotated the oven to moderate the temperature. Perhaps a data glitch?
Cooking was proceeding pretty much according to plan, so I once again devoted myself to other tasks. When I checked the on-line monitor at 5 p.m., I discovered that the temperatures had flatlined—I had lost wifi connection from the oven to my local network at around 4:20 p.m., with food temp at 106F and oven temp at 194F (6). The actual temperature was still increasing, of course, and the food temperature, as read on the Solrmatic’s readout panel, was over 200F.
Mike and I had seen this problem before when the oven was rotated all the way to the west to catch the late sun. Seems as though the position of the oven somehow interferes with the Solrmatic’s wifi antenna. I repositioned the antenna (the white dongle that looks like a thumb drive in the picture), and moved my network’s wireless router around (located on the windowsill of my office about 25 feet away, around a corner of my house). No success.
This is a bug that Mike and Belinda hadn’t seen at their house. Their wifi setup is necessarily different, and since they don’t get late sun in their back yard, their oven never rotates to this position. I’ll leave the debugging to Mike, but it can probably be cured by repositioning the Solrmatic’s wifi antenna—perhaps with an extension cable.
In any event, the sun had done its work, and the lasagna was cooked to perfection when I took it out at 5 p.m. We ate at 6 p.m. while the lasagna was still hot. We served it with a salad, and had the strawberry shortcake for dessert. Our tastebuds rated the afternoon a resounding success, despite the unresolved technical glitches.
I didn’t really exercise the Solrmatic’s ability to rotate the oven away from the sun to keep the food from getting too hot; it was late in the day, and I was going for maximum heat. I checked that the feature was working, though, and recognize that it would be valuable when there’s a danger of overcooking the food—mostly when cooking fish or chicken, which cooks quickly, or red meat that you don’t want too well done. And the food temperature probe is very useful for food like pork roast, where you want to make sure the center reaches a safe temperature.
Automatic control and temperature monitoring is great for unattended cooking—you can log in from work and see how dinner is progressing. It would be nice to be able to change the oven settings remotely (end time, duration, and temperature) as well.
Bottom line is that the ability to hold a preset temperature automatically and to monitor your oven remotely are useful and fascinating features. Of course, the Solrmatic’s ability to regulate temperature is limited to slowing the solar heat gain—it can’t produce sun on a cloudy day. But then, neither can I. I look forward to spending more sunny afternoons with the Solrmatic.
So far the cooking entries have been pretty heavy on the meat recipes. And because I’m sure Mark Bittman and Michael Pollan have been loyally reading along, they are shaking their heads in dismay at my cooking selections. It’s not that I don’t cook vegetables (though if Mike had his way, vegetables would never be allowed in the solar oven!) - I just don’t write about it, because it seems pretty mundane and not very adventurous, at least the way I normally cook them.
But if you’re new to solar cooking, vegetables can be the gateway foods to trying more ambitious recipes. I mean, vegetables grow outside in the sun already, and usually you can eat them raw, so there seems to be very little downside to putting them in a solar oven for an hour. I’ll admit with my first solar cooker, I was suspicious that the thing would even work or that I wouldn’t get food poisoning. I certainly wasn’t going to die trying, so my first few recipes were confined to brewing teas and cooking some rice. But once I’d cooked a pot of bean to complete mush a few times, eventually I became convinced that it really is hot in there and no critters could survive that environment. With the Solrmatic, the real-time temperature feedback also helps to confirm that everything is good and done; but prior to the Solrmatic, an oven thermometer and a food probe provided similar information. (For the record, I can’t think of a single instance of food-borne illness from eating solar cooked food at home, while I’ve had a number of unpleasant experiences from eating out at restaurants.)
One of my standard vegetables to cook in the solar oven is beets. I’ve tried eating beets raw before and didn’t care for them. But usually when you roast them you then have to let them cool afterwards so you can peel them. So beets are perfect for those days you don’t have time to be tending your oven and then they can be stored for eating throughout the week. Just cut off the tops and rinse, but don’t dry to let the residual moisture create a little steam.
I saw this recipe from Cooking Light for a kale salad with beets and roasted garlic dressing. Hmmm, I’ve never roasted garlic before in the solar oven. Could it be done? My second pot was already claimed, so I would need to multitask. Here is my solution (the pot is uncovered just for the purpose of taking the picture):
I didn’t want any of the beet runoff to color the garlic, so put the garlic in a small dish. After about an hour and a half, the garlic skins were still papery, so they hadn’t steamed too much, and squeezing the cloves created oozy garlicy goodness. I used the roasted garlic in the dressing as written, but omitted the bacon (really, Cooking Light?! plus I’ve already cooked bacon in the solar oven). The salad tasted better than maybe it photographs - need better lighting in the kitchen!
So what else can I use roasted garlic for? The possibilities are almost endless! Though, now I feel like I should go buy some breath mints…
The Solrmatic team will be LIVE at Maker Faire Bay Area 2014 in San Mateo, CA on May 17 and 18. We will have the Solrmatic1000 on display and you will also get a preview of the Solrmatic2000 that has been in development but yet to debut. Some new features in the 2000 model include a Beagle Bone Black instead of Raspberry Pi, a digital compass with magnetic variation adjustment, smaller and lighter form factor, and all-around improved design (i.e. more lights and switches). Come meet Mike and Belinda in person to see if we weigh 500 pounds from testing all of those solar baked cookies. Buy your tickets now.
In anticipation of this event Makezine, the organizers of Maker Faire (or otherwise affiliated), invited Mike to write a guest blog post about the Solrmatic, which you can read here. (If you have been reading the Solrmatic blog closely, you will notice that this guest post is quite similar to a previous post.)
We hope to see you in San Mateo in a few weeks!
Recently I had a full day of solar cooking planned and that morning I woke up literally having had a
dream NIGHTMARE that the whole day ahead of me was CLOUDY! Ack! If there is one thing that the Solrmatic does not have the power to do, it is to shoot laser beams at clouds to make it sunny. But I looked out the window and things looked pretty sunny. So after that crisis had been averted, my thoughts wandered to breakfast and the sad fact that with our sun exposure I can probably never have a solar-cooked breakfast…at least not during traditional breakfast time.
I thought about breakfast for dinner and remembered a recipe I had seen for baked eggs. I didn’t remember the exact recipe so I went online to look, and after typing in “baked eggs” Google so helpfully then suggested “baked eggs in avocado.” (Go ahead, search for yourself!) Hmmm. I’ve never heard of such a thing, but avocados are on sale this week and we always have eggs! There were multiple recipes and I ultimately relied mostly on this one for inspiration, well, because it uses bacon! And everyone knows that everything is better with bacon, so it would practically be foolproof.
Hmmm, but how would I cook the bacon? We’ve put bacon on trays in the regular oven before because it seems less messy and you can cook more at one time. Would it also work in a solar oven? This blog is supposedly about exploring the boundaries of solar cooking, so it seemed worth a shot.
Here’s the bacon (which I brought home myself):
And here’s the uncooked egg in avocado. This is the prettier looking one. I don’t think I scooped out enough avocado on the first one and it spilled over and was a little messy.
Based on the recipe, I was worried about tipping (especially with the spillage of the first avocado half), so I wedged the avocados between the side of the pot and a small bowl. Then I figured if I was putting the bowl in there for the whole time, I might as well cook something else. So I filled the inner bowl with 1/3 cup of brown rice and some water.
I covered the avocado pot with the bacon pan (save washing a lid! the bacon was left uncovered) and after 2 hours at full power, the bacon was nicely browned. You could actually see the bacon fat bubbling! (I took a video that did not turn out very well, but I will try to take another to post later.)
And the avocado egg also looked pretty good, too:
Garnished with some aoili, sprinkled chives, and crumbled bacon, here is Honest ABE himself:
I don’t particularly mind my eggs over hard, which is pretty much what these were after two hours.
If you want your eggs a little less well-done, you would probably need to start your bacon an hour before putting in your eggs (or I suppose take your eggs out an hour before the bacon).
Who says you can’t have breakfast after noon?
One of (or our only?) loyal blog readers requested that I make brisket. As a shameless ploy to maintain our blog following, I was happy to comply. (Note, there is now a comment section at the bottom of the page if other readers would like to come out of the woodwork and also make requests…though if I know you live in a 20 mile radius, I may suspect you of fishing for a dinner invitation.) And although brisket is a traditional Passover meal, Easter seemed as good a day as any. Last fall there was Thanksgivukkah, so why not Eastover in the spring?
I’ll admit that this has not been a bona fide food blog either, so this post will attempt to be a little more authentic, though still not up to the bar of Deb over at Smitten Kitchen. But the moral of this solar cooking lesson is that not everything needs to be cooked exclusively in the solar oven. There are certain things that cannot be done in a solar oven (or possibly in any oven), for example sauteeing.
Advanced planning warning: this recipe requires “marinating” the meat over night so might not be a good choice for an impromptu meal (if there is such a think as impromptu brisket that requires 4+ hours of cooking…).
Here are the ingredients that I started with based off of this recipe that I found online. The beef shown here was about 4 pounds (which is actually just half of the piece that we bought. I froze the other half, so stay tuned for how that one turns out - maybe I’ll go pure solar energy on that one).
Heat up some oil in a large skillet (I used nonstick, I don’t know how different it would be to use a traditional skillet, but in my experience, nonstick seems to caramelize the onions better.) and add three sliced onions along with some brown sugar and salt. Like this:
And eventually they will turn brown and the flour and tomato paste can be added:
Next add minced garlic:
And then finally broth (tip: solar ovens are great for making your own stock!). I had considered adding red wine instead of broth because we have so much (mediocre) red wine. But Mike frequently accuses me of taking too many liberties with recipes, so in the name of science, I tried to stay true to the recipe so we would have a control.
Meanwhile, while that is simmering, mix together the salt, onion powder, garlic powder, paprika, and cayenne pepper to form this rub:
I pricked the meat all over with a fork, but the pictures did not really come out, so you’ll just have to believe me. Then rub the rub all over, wrap tightly in plastic, and chill overnight.
The next morning, spread half of the oven mixture in my trusty glass baking dish along with some bay leaves and thyme sprigs.
Add the meat, and then smother it with the remaining onions. And don’t forget the temperature probe.
My impression of brisket is that it needs to cook forever, so I put this in the solar oven (with cover, of course) at 10am. I set the oven temp to 300 degrees knowing that it would never get that hot and the food temp to 175 degrees. But by 2pm, the internal temperature was already above 180 degrees!
So in went a tray of cookies ON TOP of the brisket and I upped the food temp to 200 so the cookies would bake and the brisket would keep stewing. And then when the cookies were done, I preheated a serving bowl, with minimal impact to the temperature of the main dish. I don’t know why it has taken me so long to figure out dual layer cooking, but this might be the solution rather than getting a second solar oven (and Solrmatic).
Finally it was time to eat. After seven hours in the solar oven, the brisket came out and the sauce was put in a skillet to reduce on the stove (remember this week’s moral?), though I forgot to add the vinegar to give it an extra kick. Oh well, next time.
Then sliced up and sauced:
I was worried that cooking to an internal temperature of 190+ degrees would mean that it would end up dry, but all of the onions and broth seemed to prevent that. And our (nominally) Jewish taste-tester declared it better than his mother’s!
So for the full Eastover meal, in addition to the brisket, but not depicted, we also had:
There were even some leftovers, except of course for the cookies.
Happy Eastover, everyone!
Time lapse cookies
Solar ovens are not just for making organic, fair trade, pasture raised, grass fed, shade grown, all natural granola. Sometimes you just want to eat some refined sugar and butter, which is best served warm out of the (solar) oven.
To avoid having to eat three dozen cookies over a few day while they’re still fresh, I wanted to see whether I could make all the dough, freeze cookie-sized portions, and then bake them in smaller batches. I wasn’t sure whether the lower temperature of the solar oven would be enough to bake cookies, but in my online research I found that supposedly this is the secret to Mrs. Field’s chocolate chip cookies.
I started small with just a solitary cookie on a black pie pan. And to help boost the temperature of the oven, I put an inverted cast iron pan under the pan.
In goes the probe and about 45 minutes later out comes a cookie!
One cookie turned out to be not enough for Cookie Monster (duh), so I had to expand to six:
See the post below to watch these baking in time lapse!