Boiling pinto beans in a solar cooker

Yes, solar cookers really do get hot and cook food! My Sun Oven reaches 350°F easily. The boiling point at sea level is 212°F. The boiling point at 7,000 feet elevation is 199°F.

Sunny Side of Cooking Book Cover

Solar cooking garbanzo French fries and rice for lunch

At this time of year, the south-facing area in front of my front door and side garage door is the best location for solar cooking. In fact, it’s quite a bit hotter than the microclimate on my south-facing balcony in Flagstaff was, so everything cooks significantly faster and I am having to adjust some of my cooking times and adding extra liquid to the cooking pot.

I cooked garbanzo/chick pea flour (besan in Hindi) polenta in the Sun Oven, and then baked the French fry-like slices in my indoor oven after it cooled; I basted the slices with olive oil before baking. After cooking the polenta, I cooked some brown rice and wild rice to go with the fries. The “fries” were a hit with my wife, LynnAnnRose, a relatively new vegan.

Solar cooking in my Santa Fe backyard

Most of my new backyard faces west and north and is heavily shaded by trees. However, a strip of land along the northern side of the house receives plenty of sunlight between the morning and early afternoon during the couple of months on either side of the summer solstice. I’ve decided to use my solar cooker there, directly on the ground, for now. Monsoon clouds and rain tend to appear in the afternoons when that piece of land is shaded by the house anyway. I like this location because there is easy access to the kitchen through the patio door and the dining room. I am storing the cooker uncovered underneath the patio overhang to protect it from rain. During late fall, winter, and early spring, I’ll have to use the cooker in front of my house, which faces south; that location will require carrying food up and down half a flight of stairs, and through the front door and front gate, and storing the cooker in the garage.

Solar cooking forgotten lentils in the pantry

I’m in the process of packing for our move to Santa Fe, New Mexico. One thing I’m doing is cooking remaining foods in storage so that there is less stuff to move. I found this several-year-old jar of brown lentils in the pantry. Lentils last forever, at least in terms of human lifetimes, making them good for long-term/emergency storage.

I decided to cook the entire jar. Now that the summer solstice is fast approaching, the rod at the back of my solar cooker is adjusted so that the cooker face is almost horizontal to capture the most sunlight during the middle of the day when the sun is almost directly overhead. Lentils are quick-cooking legumes and don’t need pre-soaking.

Lentils are cool season legumes that grows well at high altitudes. In hot climates like the Middle East, Ethiopia and India, where they are staples of local cuisines, they are grown during the cooler months. In my climate, however, they are grown during the summer.

Solar cookers can cook anything

Adapted from The Sunny Side of Cooking: Solar cooking and other ecologically friendly cooking methods for the 21st century:

It is possible to use a solar cooker for everything from simmering to blanching, poaching, steaming, sautéing, braising, baking, roasting, toasting, grilling, barbecuing and pan frying. Most of these methods can be done in a box cooker. A few require the extra high temperatures only achievable with a parabolic reflector.

The foods above include chocolate tofu pie with a gluten free almond crust, baked kabocha squash, barbecued tempeh made with home canned barbecue sauce, minestrone soup with beans precooked in the solar oven, steamed corn on the cob, home grown rhubarb crumble, and whole wheat sourdough raisin bread. Enter “raynersolar” into my “Search Lisa’s Blog“ search box to see all of my original solar cooking blog posts (not reblogs). Use my Google search box to look up specific foods and dishes.

Nov. 18, 2015

Safe solar pressure cooking and canning


The only two types of canning that are considered safe by the USDA are boiling water bath canning and pressure canning. Do not follow directions for solar “air canning or “oven canning” in which the jars are surrounded by air, not water. Foods canned using this method are at risk for the growth of spoilage bacteria and fungi, as well as botulism bacteria.

The Kerr-Cole Large Solar Panel/Propane Hybrid Stove

Pressure cooking and canning can be done easily in a reflector-only cooker, such as a panel cooker or parabolic reflector.

Barbara Kerr was a pioneer in the solar cooking movement. In the 1970s Kerr and her neighbor Sherry Cole designed the first commercial solar oven kit, a cardboard solar box cooker. Later, her home in Taylor, Arizona became the Kerr-Cole Sustainable Living Center. I feel honored to have known her.

Kerr and engineer Jim Scott conducted experiments with solar pressure canning and medical sterilization. Barbara always saw the world as the world’s poorest people see it. She wanted her inventions to be buildable by ordinary people using cheap and preferably recycled
materials easily available locally.

This large panel-style cooker was built out of four 4’ x 8’ plywood sheets covered with aluminum foil. The panels heat a huge 46-quart All-American pressure canner that has been painted black. The sterilizer has an emergency metal/spring or neoprene disk for safety pressure release. Metal disks that melt as an over-pressure safety release do not work since they melt prematurely from the solar heat that falls on the top of the vessel.

For insulation, a chicken wire cage is wrapped around the canner,
leaving an air gap for insulation. A sheet of plastic, such as a
discarded piece of mattress wrapping, is wrapped around the chicken wire cage to act as a giant cooking bag. The trick is maintaining the right balance of heat retention and venting so that the canner remains at high pressure throughout the canning period. Because pressure canners have both a temperature gauge and visible vent steam, it is easy to see when the temperature and pressure is correct.

Most importantly, the system has a back-up propane heater
designed to kick in if clouds obscure the sun during the middle of a canning run. In order for the contents to be safely sterilized, the
pressure must not be allowed to drop.

Adapted from The Sunny Side of Cooking: Solar cooking and other ecologically friendly cooking methods for the 21st century solar cookbook and The Natural Canning Resource Book: A guide to home canning with locally-grown, sustainably-produced and fair-trade foods

A winter day in the life of an urban homesteader

I started my day by feeding my sourdough starter. I did some knitting. At 9:00 a.m. the outdoor temperature was around 22°F. I opened the solar oven to preheat it. After breakfast I put the beans in the solar cooker; the cooker reached 300°F at its hottest point an hour or so later; the daily high temperature was around 40°F. The snow on the ground reflected extra sunlight into the cooker. The air temperature had very little effect on the cooker temperature; the low angle January sunlight had a bigger effect on lowering the temperature.

After breakfast, I ground whole wheat flour by hand for 15 minutes (amount pictured) and fed the starter for the third time. I kneaded my bread dough, stopping to grind more flour as needed (a full loaf contains 16 oz of flour, including the flour in the starter). I left the loaf to rise for a couple of hours. When the bread was risen, I baked it at 375°F. I removed the cooked beans from the solar oven around 2 p.m. I let the bread and beans cool down on my kitchen counter.

In the afternoon, I spent some time weaving cloth and doing miscellaneous chores. I added the cooked beans to a stew with winter vegetables for dinner. I used my pressure cooker to make the stew. A pressure cooker is an enormous time saver at 7,000 feet; pressure cookers also save a lot of stovetop time, and therefore fossil fuels, too.