Cooking out of the box
Glass, aluminum and wood are the ingredients of the solar oven, which both saves energy and produces surprisingly succulent foods.
Sometimes, when people want to describe a sweltering summer day, they say it's hot enough to fry an egg on the hood of their car. Channeling the sun's heat for cooking, however, is nothing new to Ruthie and Yaakov Dorot of Netanya.
"We want to tell you about the oven we built by ourselves," they wrote me, following a recent article in these pages ("Delayed gratification," September 7) on the virtues of slow cooking. "Since 1996 we have been cooking a variety of tasty, healthy foods at low temperatures. Our oven uses energy from the sun, and of course is more efficient in the summer."
The letter was accompanied by a photo of an intriguing wooden box with a transparent cover. I contacted the Dorots, asking for more details (and hinted that I would like to see the oven myself).
"The oven is actually a wooden box with a double-glazed cover," came the reply. "The inside of the oven is lined with aluminum, painted black. The ingredients for cooking are put into black enamel pots, to absorb the heat better, but covered Pyrex dishes can also be used. The cooking is done at 100 degrees Celsius. We put the food in the oven in the morning, when we leave the house, and when we come back at lunchtime, the meal is ready."
The letter ended with an invitation for lunch on the roof, where I could taste the results (they had gotten the hint).
The Dorots first encountered the idea of harnessing the sun's rays for cooking purposes during their seven-year sojourn in chilly Switzerland, where Yaakov, an engineer, served as an Israel Military Industries emissary in the late 1980s and early 1990s. A Swiss friend invited them for a meal and served ratatouille prepared in a solar oven - a box that works on the same principle as solar panels used to heat water.
It turns out there is a Swiss company that manufactures and sells solar ovens in build-it-yourself kits, for people who care about the environment and energy conservation. The kits also have a humanitarian purpose, and are distributed in hot countries, in underdeveloped regions with no electricity.
"I immediately liked the idea," recalls Yaakov, whose professional sixth sense identified an interesting technical challenge. "I asked my friend for the assembly instructions from the kit, and brought them back to Israel."
One of Dorot's first projects after returning here became the collection and improvisation of the necessary materials, he says. "For the lining of the oven I used discarded metal plates from offset printing; the clasps that hold the bar that keeps the oven's lid open are recycled from an old car hood; a carpenter friend helped me build the box itself; the nontoxic black paint is honey-based and was bought for me by friends abroad. Little by little I reconstructed the oven."
When this was done, Dorot borrowed a thermometer from an automotive electrician, set the oven on his roof, in the sun, and tested the device. To his disappointment, the temperature inside the oven did not exceed 96 degrees Celsius (the goal was to reach 100). Dorot did not give up. He fitted the lid with a rubber insulation seal, and tried again. This time the inside of the oven got hot enough to boil water.
"We use the oven almost every day, from May through September," says Ruthie. "I prepare the food in the morning, before we leave the house, and when we come back tired in the afternoon, our meal is ready - tasty and healthy, like in a restaurant. Apart from the ecological considerations (we did not build the oven for economic reasons, but rather to save energy and reduce pollution), it is simply very convenient to use a solar oven. The food stays succulent and tasty, and doesn't burn or dry out. It doesn't matter if we come home an hour later or an hour earlier.
"We cook mainly stews, rice and lentils, legumes and vegetables, but also chicken, meat, fish and patties. Sometimes I saute the onions or other vegetables first, on the gas stove, add seasonings and then set everything to slow-cook in the sun. Sometimes we even cook enough for several days, and use the solar oven for reheating. The food comes out delicious."
After all the explanations (and the first course: stuffed eggplant a la Moussaioff, prepared on the stove and served cold - a secret family recipe that Yaakov revealed to me and which will be published here soon) came the main event: The lid of the box was opened and out came pots of delicious rice with vegetables and lentils, sumptuous chicken patties in tomato sauce with fresh za'atar (wild hyssop), and a festive pot of chunks of chicken breast with red apples. Ruthie happily gave me the recipes and apologized for not knowing the exact quantities of all the ingredients.
If you do not have a solar oven, these dishes can be made in a regular oven, set at 100 degrees Celsius.