1 ) Temperatures in solar cookers
2 ) Duration of cooking
3 ) Cooking pans
4 ) While cooking
5 ) Preservation of foodstuffs
6 ) Drying of fruits and vegetables
7 ) Sterilising drinking water
8 ) Maintenance of the solar cooker
9 ) More tips for cooking...
The temperature inside a solar cooker can reach 170ºC but it is possible to cook already at 80ºC. To reach the maximal temperature the sky needs to be clear, the window clean and the position of the box and reflector needs to be corrected from time to time to capture the maximum of sunlight. Adjusting the cooker every 30 mins would be the most efficient but, in general, it is sufficient to keep it oriented towards South.
The best period to cook the meals is between 9:00 and 16:00. If there are clouds or the meal is to be consumed only after sunset, it is better to close the lid when the temperature sinks to 80ºC. The dishes can remain warm for 2-3 hours. The heat can be retained for even longer if the surface under the pan is covered with black stones or a layer of sand is placed on the inside walls of the oven. For the latter to work, the sand must be covered with a black-coated layer of aluminium of iron.
- 100 ºC: The water boils
- 85 ºC: The water is Pasteurised (sterilised)
- 82 ºC The dishes start cooking
- 71 ºC Pasteurisation of foodstuffs
- 49 ºC Most bacteria can not multiply
- 22ºC Room temperature
The duration of cooking depends on the temperature and the type of food being cooked. When the oven is very hot, one should count with double the normal time of cooking. A temperature of 80ºC is sufficient to simmer the food and cook it slowly. the cooking time is longer but the vitamins and nutrients are better preserved.
It is possible to use pans or pots made out of iron, aluminium or stone ware. Metal pans conduct the heat faster but the most important is the black colour on the outside walls (to better absorb the heat ).
They should be covered with a lid, either coloured black as well or then made of glass. If the pans available are light coloured, then can be painted with a non-toxic dispersion or black board paint. It is preferable to use two smaller pans or ots side-by-side, instead of a single larger one.
As soon as the pans are in the solar cooker, you can occupy yourself with other tasks. It is not necessary to take care to the oven while it is cooking. The dishes cannot burn nor overcook, and it is not necessary to turn the food since the heat is equal from all sides. To preserve the temperature inside, it is best to leave the lid of the pans and the window closed while cooking.
Some dishes are not suited for solar cookers: noodles that need to be cooked in hot water, such as spaghetti or macaroni, and grilled or fried dishes, which require an higher temperature. Otherwise, almost any dish can be cooked in a solar oven.
To prevent insects from developing in dried rice, beans or flour: place the food in a tightly closed paper bag and then leave the bag inside the (hot) solar cooker for a few hours.
The oven can also be used for drying. Spread the sliced fruits (e.g., banana or mango) or vegetables (e.g., tomatoes, peppers, green beans and so on) on one or two grids and place the grids inside the oven so that the hot air can circulate around the slices. Leave the window slightly open, with one or two small sticks, so the humidity can go out.
Water can also be sterilised with the solar cooker. Put the water inside a pan or black container and leave the water at 80ºC for at least 20 mins. This is sufficient to kill the bacteria and other microorganisms in the water.
To allow most of the sunlight to get in, the window must be kept clean. Use a dampened smooth cloth to clean the inside and outside of the window.
After use, the solar cooker must be sheltered from rain. In case it gets wet, it can be dried out in the sun; just leave the window a bit open so the humidity can go out.If there is condensed water between the two glass panes, the pane can be unscrewed and removed to dry. If the black paint is damaged, it should be repainted.
Nearly all dishes that are cooked with moderate heat can be done in a solar cooker with very flavourful results.
If nothing else is said, the pan should always be covered with a lid.
When cooking rice, place the normal amounts of rice and water inside a black cooking pot. Usually, one measure of rice and two measures of water are used but you can adjust it to make the rice drier or moister.