Well, this month's column isn't about tents, but it's about camping. In particular, it's about a cooking method we almost always use when we camp. It's about solar cooking. When most people think of solar cooking, they're probably remembering something they read in the paper years ago about elaborate reflector mechanisms that use complicated clockwork to track the sun. They think of the technology as expensive, bulky, and tricky to use.
The system we use is nothing like that. It uses a very simple cardboard reflector that anybody can make with a little tinfoil and some scrap cardboard ... but why make it, when you can buy the reflector for all of $20.00 retail? It also uses a black enameled-steel pot and an oven roasting bag like the kind you buy at the store to roast your Thanksgiving turkey in. It folds down into a compact shape (about a foot on each side and about an inch thick) that weighs about a pound and stores easily.
What can it cook? Practically anything a slow cooker can cook ... pot roasts, chicken, rice, casseroles, and just about anything else that uses low, steady heat. It can bake potatoes easily in about three hours, and can even bake breads and cakes if used in a bright noonday sun.
Although the cooker works better in bright sunlight, you can get acceptable results even in hazy conditions; cooking just takes longer. Our rule of thumb is that if there's enough sun to cast a shadow, you can use the cooker.
The biggest advantage of solar cooking is that once the food is cooked, it stays warm without overcooking. We put the rice in at around 2 p.m. and plan on eating at 6:00 p.m., but if things come up that change our plans, we know that the rice will be ready as early as 4:00 p.m., or will stay warm and eminently edible as late as 7:00 or 8:00. You can similarly prepare pot roasts, stews, and combination meat/vegetable dishes with the same flexibility in cooking time.
Solar cookers operate on the principle of the slow cooker. It typically heats up to around 200-250 degrees, which is plenty hot enough to cook most things. In areas where the water supply is contaminated, it's also used to pasteurize water for drinking.
To use our cooker, we put the food into a black enameled-metal pot. This pot goes into the roasting bag, with a little rack or trivet to keep the pot from touching the bag on the bottom. The bag is then sealed with a twist-tie, or clothespin, or whatever, and the whole assembly is placed into the reflector. The cooker is then pointed to that portion of the sky the sun is expected to occupy at about the halfway point in the cooking time. Due care is taken that, as the sun moves along the sky, it won't be eclipsed by a tree or a building during a major part of the cooking cycle. That's all there is to it.
Here's how it works. The oven roasting bag provides a still air pocket around the pot. The cooker's reflector directs the sunlight through the bag onto the pot, which absorbs the sun's heat, while the trapped air keeps that heat from escaping back into the outside world. Black enameled pots work better than cast iron pots because they take less time to come up to cooking temperature, and therefore end up transferring more of the collected heat to the food. And they're cheaper and lighter, too.
We also have a solar box cooker at home that operates on the same principle. The aforementioned black pot is put into an insulated box with a top made of two layers of glass. A shiny surface is so arranged as to direct a maximum of sunlight into the box. Cooking times are about the same. The only advantage of the box cooker is that it can accept two or three pots instead of one, so we can cook more food at a time.
One of the oldest and most active promoters of solar cooking technology is a group in Sacramento, California called Solar Cookers International. It was founded to promote the use of low-technology solar cookers in areas of the Third World where sunlight was abundant and fuel was scarce. To fund their activities, they sell solar cookers a modest profit. With the proceeds, they send teachers to countries where the cookers are needed most and teach the people there how to make and use them. When food came into the big refugee camps in Africa a few years ago, there wasn't much fuel to cook it, and solar cookers made a real difference. And you can imagine what a difference in life-style a family can achieve if they don't have to spend hours each day collecting enough firewood to cook their meals.
Of course, solar cooking isn't perfect. Some days, it rains. Sometimes you don't have the time to cook stuff slowly. But most of the United States, Australia, and other temperate-zone countries have enough sunlight in the summer months to stoke a solar cooker.
For more information, you can contact Solar Cookers International at 916-455-4499, or write them at 2400 22nd St., Suite 210, Sacramento, California 95818. Their web site is http://www.solarcookers.org/index.php. On their site, they've posted complete plans for making solar cookers and information on how to use one. Or you can buy a finished cooker, pots, cookbooks, and much more from them at the same site.