Cover Image
close this bookSolar Cookers in the Third World (GTZ, 1990, 228 p.)
close this folder3. Conditions of Acceptance for Solar Cookers
View the document(introduction...)
View the document3.1 Preliminary Notes
View the document3.2 Solar Radiation
View the document3.3 Energy Demand
View the document3.4 Social Situation
View the document3.5 Dietary Patterns
View the document3.6 Eating Habits
View the document3.7 Cooking Habits
View the document3.8 Use of Stoves, Fireplaces and Hearths
View the document3.9 Solar Cooker Technology
View the document3.10 Economic Efficiency
View the document3.11 Direct and Indirect Impacts
View the document3.12 General Conditions of Acceptance
View the document3.13 Summary

3.5 Dietary Patterns

Solar cooker projects can hardly be expected to change people's dietary patterns, but they must at least be suitable for use in cooking most of the main dishes.

Staple foods: The staple foods of a population can differ quite substantially, depending on the country, region, local traditions, crop harvests, availability, season of the years, etc. No solar cooker project should be implemented without a good working knowledge of the prevailing staple foods. Five examples:

- India: Rice and wheat are the two staple foods. Most rice is cultivated in the southern part of the country, and most of the wheat is grown in the North. Legumes, chick peas (grams) and various vegetables are also eaten. Meat plays a subordinate role. In the poorer households, millet (panic grass) is eaten in place of rice and wheat. Eggs, milk and other cereal products are eaten more in well-to-do households than among the poor.

- Kenya: The principal food in Kenya is corn (maize), followed by beans, various leafy vegetables and tubers. In some areas, goat meat and poulty, potatoes and eggs, cooking bananas and various vegetables are eaten when available. The Nomads in northern Kenya live on milk, meat, corn meal and little else. They eat mostly meat during the dry season and milk (products) during and for a while after the rainy season. Due to lack of infrastructure, corn is not always available. Corn consumption is concentrated mostly in the interseasonal months when lactation has not yet begun, but the consumption of meat already has to be reduced.

- Mali: Millet, corn and rice are the principal foods in Mali. To the extent available, and depending on their ethnic background, people also eat vegetables, meat, fish and cabbage, the latter seldom. In southern Mali, millet and rice are preferred, along with peanuts, ocra, sweet potatoes and fish. The leaves of the fiber plant hibiscus cannabis are widely used in preparing sauces. A fat traditionally extracted from the fruit of the shea butter tree is used as cooking oil. In the central area, squash, tomatoes, sweet potatoes, rice and onions are very popular. The Nomads in northern
Mali live chiefly on milk products, meat and fish.

- Pakistan: In this country, the two staple foods are rice and wheat. Lentils, beans, various vegetables, herbs, and meat are prepared together in stew fashion. While fish is an important source of nutrition for people living in Karachi and other coastal areas - particularly on the "meatless' days prescribed by the government - many people in the mountainous regions live almost exclusively on fruit, vegetables and grain. Families with above-average incomes also consume eggs, salad, fruit and wheat products. Afghan refugees in northern Pakistan have bread, vegetables, meat, and tea as their primary foods /184/.

- The Sudan: The staple food is durra (primarily sorghum plus some millet), in addition to tomatoes, broad beans, potatoes' lentils and vegetables, usually in the form of stew, which may also contain mutton and goat's meat. Due to sinking income, a bean dish called foul is gradually disappearing from poor people's menus.

- Conclusions: People have to be able to cook their staple foods in solar cookers. As long as the staple foods are rice, cereal, grain, noodles, vegetables, potatoes and mixed dishes, e.g. stews, solar cookers can serve well, though care must be taken to differentiate between the various types. A low-temperature cooking box, for example' may be just right for social groups whose main foods are rice and vegetables, but it would not be of much help when the cook needs temperatures hot enough to simmer cooking oil or to bake crispy bread. The utility value of a particular solar cooker is more or less limited by the relative importance of cooking, boiling, steaming, roasting, baking or grilling.

Meals: The most important thing is that the main dishes with the staple foods can be prepared using solar cookers. To judge this properly, one must give due consideration to the people's morning, noon and evening eating habits, i.e. to the time of day when the main meal is taken:

- Breakfast: In rural communities, breakfast may well be more important than the midday meal (lunch). In India, to the extent that breakfast is not eaten cold - and this is where solar cookers come in - it may consist of chapatis (a pancake-shaped unleavened bread, usually made of wheat flour and baked on a griddle, and which is common in northern India) milk or milk products, and sometimes tea. A typical breakfast in Mali consists of millet gruel with milk and sugar and salt. Bread (naan) left over from the day before with tea and milk is the basic breakfast in Afghan refugee camps in Pakistan. Urban families in Pakistan often have fried eggs for breakfast. Pakistanis of Indian descent often supplement their breakfast tea and chapatis with a boiled stew consisting of vegetables, potatoes and meat. In Kenya, breakfast consists of tea with milk and sugar and a thin mush cooked in milk or water. As in all other countries, there are important differences between various social groups: The Nomads of northern Kenya eat a soup of milk, corn meal and sugar (uji) and drink tea with milk. In the Sudan, a typical breakfast consists of millet gruel, vegetables or warmed-up foul, a fresh batch of which is prepared twice a week. Tea with milk is normally drunk for breakfast. Bread is sometimes eaten as a side dish. Well-to-do families add tomatoes, vegetables, eggs, cheese or liver, while poor families make do with millet, milk and an occasional piece of jerky. The useful effect of solar cookers depends a lot on the importance of fresh-baked bread at breakfast time.

- Lunch/supper: The noonday meal often differs only insignificantly from the evening meal. That being the case, the expediency of using a solar cooker when the sun is at its highest has both advantages and disadvantages. Many poor people eat little or nothing for lunch, saving what they have for supper. In Pakistan, for example, most people eat a modest lunch consisting of a vegetable stew, meat with chapatis and/or rice. Pakistani families of Indian descent often content themselves with a snack of breakfast leftovers. Some farmers and farm workers take "lunch boxes" to the fields. Frequently, though, farm hands buy their lunch from the landowner - at exorbitant prices. Mulach, a stew consisting of meat, onions, vegetables, garlic and oil, is often eaten for lunch in the Sudan; kisra, a kind of sorghum bread, is eaten with the stew. Many poor people have only tea and milk for supper, but others eat the same dishes as for lunch. Such diverse conditions naturally have an impact on the use of solar cookers.

- Main meal: Knowledge of what is required to prepare the main meal - or the "national dishes" - is of special importance, since solar cookers will be expected to have what it takes in that connection. If the dish in question is boiled, e.g. foul, a bean dish popular in the Sudan, or dal, an Indian dish based on legumes, then solar cookers are just what is needed; the same applies to kitheri, a stew consisting of beans, tomatoes, cooking bananas and squash that is popular in Kenya, and to khichadi, an India stew made up of rice and legumes. Obviously, it would be impossible to assess the acceptance of solar cookers without knowing how the staple dishes are cooked.

Cooking staple dishes: The preparation of main dishes differs according to local tradition and the type of cooking facilities used. Additionally, the cooking temperatures and manner of cooking
(boiling, roasting, baking, grilling) also differ from case to case. Some examples:

- Mali: Tot is prepared by putting a thick flummery in roughly three lifers of boiling water and stirring steadily to obtain a firm mass. The stiffness can be increased by adding powdered baobab leaves. Couscous, by comparison, is a more complicated dish to prepare: a coarse-grained, dry noodle substance made of corn or durum wheat (semulina) is put in a perforated bowl and allowed to swell and cook in the low steam heat over a pot of simmering water. Once in a while, it has to be loosened up by hand. In some places, the semulina is cooked directly in boiling water until finished. Rice is prepared like couscous or in boiling water. The sauces are made by searing vegetables and meat in hot cooking oil, quenching with water and then cooking until finished. It takes about 60 minutes to cook tot and sauce and between 80 and 90 minutes to prepare couscous. In northern Mali, meat and fish dishes are roasted, fried or smoked.

- The Sudan: The bean dish foul is easy to make, because the beans need only be cooked slowly without stirring. Mulach, by contrast, is more complicated in that the onions are first seared in hot oil, after which meat, salt and water are added and left to boil; after a while, vegetables, tomatoes or alimentary paste are added, after which frequent stirring is necessary. Aseeda, a millet pudding, also has to be stirred frequently. Sudanese "pancakes" (kisra), made of fermented millet powder, are usually cooked on a griddle-like sheet of metal.

- Kenya: Ugali is prepared by placing coarsely ground corn meal in boiling water and stirring vigorously for a few minutes. By comparison, it takes up to three hours to cook kitheri stew. The ingredients for a meal are frequently cooked in succession, with the finished ones kept warm by placing them on top of the hot pot.

- India: The unleavened bread chapati is baked on a griddle or in a skillet over a hot fire for several minutes and then roasted briefly in the open flame.

- Pakistan: The stew (vegetables + meat), as well as the rice, is stirred steadily. Indian families use a lot of fat for cooking. All ingredients (except the rice) are first fried briefly in cooking fat and then boiled in water. Baratta is prepared on a very thin sheet of metal called a tawa. The dough is baked ahead of time and then fried in lots of fat. Chapatis are either also prepared on a tawa or baked in a tandoor (a built-in adobe oven). The dough is slapped onto the inside of the very hot oven from the top and turned after a minute or two. Some families in one compound have communal tandoors in which several families can bake their chapatis together. In the larger towns, however, people often buy their chapatis in bakeries.

- China: The staple foods require boiling, steaming, roasting, etc. for preparation. This means that high temperatures and high thermal power are necessary. These requirements are easily met by reflector cookers, while in this case cooking boxes do not perform satisfactorily.

- Conclusions: The above examples clearly show how solar cookers have to "adapt" to how the main dishes are traditionally prepared. Consequently, most people tend to use a solar cooker for just a few of the more appropriate dishes. Indian ATRC cooking boxes, for example, are used mostly for cooking rice, legumes and vegetables; in the relevant Project, among the users, 20% make use of their solar cooker only for certain dishes, and 60% use it only for one meal a day.

Bread: Most solar cookers are of little use in areas where baked bread is the main staple. While solar cooking boxes will bake breed, at least in principle, they cannot produce a crispy crust.
Afghan refugees in Pakistan, for example, eat large amounts of nan (unleavened bread made of wheat flour) practically for every meal. According to a 1983 survey of 498 households, the average family consumes 20 loaves of unleavened bread per day. Half of the women interviewed said they bake twice a day, and one in five bakes a full day's supply at once. Most nan is baked in traditional tandoors. Past attempts to replace wood with other kinds of oven fuel, e.g. briquettes or rice hulls, failed due to slight discoloration of the bread. Unleavened bread has to be baked at a very high temperature and requires heat distribution on relatively large surfaces; the cost of the technical necessities would very probably surpass the low solar-cooker price limit for poor social groups. On the other hand, some baked goods turn out especially good in solar cookers, as substantiated by reports from the Sudan.

Side dishes: In some countries, Mali for instance, the usefulness of solar cookers seems to be restricted to the preparation of entremets and sauces/gravies, as opposed to main dishes. That is surely an impediment to their acceptance. Solar cookers really should be well-suited - or even better-suited than traditional means - for cooking at least certain kinds of food, or people won't try them in the first place.

Taste: Indian housewives contend that unleavened bread loses its typical flavor if baked in a solar cooker. Indeed, they say, other dishes also come out tasting different if they are cooked in, say, an ATRC cooker. Under such circumstances, solar cookers can hardly be expected to find acceptance. The extent to which the taste of Sudanese food is altered by cooking in a solar cooker is a point of controversy.

Beverages: At first glance, solar cookers appear to be just the thing for preparing beverages, above all tea. In some cultures, however, the men like to spend lots of time preparing and drinking tea around an open fire - in the shade. In Mali, where the practice has taken on a nearly ritual character, this has had a definite limiting effect on the use of solar cookers. The same is true in the Sudan, where the low efficiency of the most commonly used type of solar cooker makes it unsuitable for brewing tea quickly - and tea is taken with all meals as well as at dawn and dusk.