Chiwaya chicken and chips fried in transformer oil

3rd January 2010

Chiwayas street food vendors along the roadside in Malawi

It is Malawi’s favourite snack with fast service, convenient locations, and value for money. Those with extra notes in their pocket will line up at Hungry Lion, while others will take a short walk to their local chiwaya for probably Malawi’s most popular dish – chicken and chips.  A chiwaya is a portable makeshift stove – consisting of a flat metal sheet sunken in the middle,  with a compartment underneath for placing charcoal, and long metal stilts for legs. They are mobile and conveniently located during the day near office blocks, schools, and bus stops while at night at discos and bars. On the menu for the cheap price of anything from MK20 to MK100, you get greasy, soft (less than crispy), fat chips boiled (not fried) in cooking oil, a threadbare, hard (but tasty) piece of chicken and coleslaw (cabbage salad) packaged in small blue plastic bag (I don’t know why, but most of the time its blue).


There are all kinds of health and safety hazards associated with chiwayas – the less than sanitary cooking conditions, the source of the water for washing the potatoes, and the quality of the oil. I once went without electricity for two days because oil had been stolen from the transformer supposedly for use by chiwaya vendors . Being the curious person that I am, I sought to find out the possibility of transformer oil being used in the cooking process. Theft of transformer oil is common in Zambia, Zimbabwe and Tanzania costing the electricity supply companies millions of dollars to replace damaged transformers. Stolen transformer oil has three main uses, it is mixed with diesel and sold as fuel; it is used as fuel for industrial furnaces; or it is mixed with vegetable oil and sold as cooking oil. According to my quick research – oil that is used in transformers is mineral oil which helps keep the transformer cool and insulates it. Mineral oil is different from normal vegetable cooking oil as mineral oil is made from petroleum (fuel).  It is very stable at high temperatures making it better for frying but it can be toxic to your body and cause diarrhea. The advantage of mineral oil is it does not deteriorate as fast as standard vegetable oil and is extremely low in calories. Heat and exposure to light damages vegetable oil producing  harmful substances. Deterioration of the vegetable oil by constant reuse and poor storage results in poor quality oil that has a dark colour, altered flavor, harmful substances, and a reduced smoke point (temperature at which a oil begins to break down and release irritating smoke).

A study done by researchers from Bunda College in 2006 assessed the quality of cooking oil used by vendors in Lilongwe market. There study unfortunately did not look at the use of transformer oil in cooking but the authors were able to conclude that the oils being used were of poor quality and present health hazard to the consumers and the processors themselves. Most of the vendors used named brands like Kukoma and Superstar but had inadequate storage and often reused them for several days just topping them up with new oil. Chemical analysis of the oil obtained from these vendors showed high levels of harmful substances. These harmful substances fatty acids and free radicals have been linked with chronic diseases like diabetes, cancer, and heart disease.

It is not only the poor quality of cooking oil that worries me but the increasing daily consumption of this high fat delicacy. Diets high in fats not only cause weight gain but lead to complications like obesity (excess body fat) and chronic diseases like heart disease, stroke, and diabetes. So it is double trouble, because if the poor quality oil does not get you then the high fat will. The idea of medical conditions like obesity and heart disease becoming a problem in Malawi may seem laughable to you when we are currently grappling with severe infectious diseases like malaria, AIDS and tuberculosis but studies done by the World Health Organization suggest there is an invisible epidemic  of an overwhelming number of chronic disease cases in poor countries . The WHO estimates that 80 percent of chronic illnesses like heart disease, stroke, cancer and diabetes are in low-income or middle-income countries, contrary to a popular belief that these diseases largely afflict people in wealthy countries.

The answers does not lie in banning chiwayas but in the Ministry of Agriculture putting their National Plan of Action for Nutrition into action and educating consumers on balanced healthy diets, vendors on food quality and safety factors, and maintaining adequate public health facilities for street food vendors.

17 thoughts on “Chiwaya chicken and chips fried in transformer oil

    • No side effects, as far I know ,have been documented …but this probably is because no real study has looked into this.

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    • Chinese companies in Malawi are manufacturing cheap cooking oil which is replacing the need to steal transformer oil but it too is not very good. Malawi Bureau of Standards have shut down a lot of these companies for substandard products.

  6. Chiwaya chips is what most of us go for during lunch time because it has a reasonable price as compared to chips from Shoprite or Hungry Lion. I suggest fo sanitary issues the City Assembly should organize the Chiwaya vendors to have association which will among others look into the recommended cooking oil to be used ,and anybody who does not comply should be banned .

  7. Last month the Malawi Bureau of Standards published a list of companies that had been closed because of poor standards…on the list were several chinese companies that manufacture cooking oil. Its a step in the right direction.

  8. i haven steeling transforma oil and selling to big hotels in kenya and the oil has a very high demand on kenya so yes transforma oil is used in cooking

  9. I know we have good transformer oil which can still be used for transformers, and ‘bad’ ones which can no longer be used for transformers. Now, can this ‘bad’ one be used for frying chips and mixing with diesel too?

  10. I have just heard form a friend that my favourite fish joint in Eldoret;Istleigh uses transformer fuel.The only worry is if the transformer fuel contains heavy metal additives coz thiz might be poisoning scores of fish lovers.
    My favourite fish style is “kisumu style”.We are planning to storm the joint’s kitchen so that we can find out for ourselves.Perhaps transformers should move to using vegetable oil derivated oil to avoid such cases…Ahem…!!

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