Through the eyes of a delegate

I had only been teaching science for three years at our mixed government school when our head of science said an elderly Englishman wanted to spend a day with us and show us a way we could make some of our lessons even more interesting. He could do this letting us do experiments showing what happens to molecules in a coffee bean when made into a tasty drink. Strange idea! I had to find out more.

My colleagues and I wondered why Mr Rodney would want to come thousands of km from Britain with his wife Mama Janet to share his ideas. Perhaps it was too cold still in England in winter. It started to make sense when we learned that fifty years ago he had lived and taught in Bukoba on Lake Victoria for four years and even done his teacher training in Kampala before that. We heard that he had been so well treated by the Tanzanian government and people and been paid a lot of money for his work that this was his way of saying “Asante Sana” meaning “Thank you very much”.

I live several kilometres from our school but with a friend we got a “boda boda” motor-cycle taxi ride to be on time for the 9.30 start. Luckily the roads weren’t too muddy because the rains hadn’t started and I wanted to look smart. I’d only had time for a tiny breakfast so I was glad to know we’d break off mid-morning for coffee, tea mandazi, our delicious local doughnuts.

Some of the others had come from greater distances so Mzee - he liked us to call him that: it means “respected old man” or “elder” – had put photographs and maps round the room for us to look at. They showed him as a bachelor fifty years ago in Bukoba when the same age I am now, 23. He had plenty of hair then and it was black, not today’s liitle bit of white! Mama Janet was getting some special pieces of equipment ready like the hand mill (grinder) for us to use along with usual equipment we have here already in school. They had brought this kit in a suitcase from England. Mama also registered us delegates as we arrived. We wrote down our full names (needed for the certificates of attendance), email addresses, mobile phone numbers, places of qualifying, specialist subjects, and number of years teaching experience. I was willing to give them this information because I trusted them to use it well. Mama Janet said we could tell them at tea-time how we became interested in science teaching. They hoped to use our answers to find out how other people, perhaps some of our students, might be attracted to the job and stick with it, tough though it is.

When delegates from further away had arrived, Mzee introduced himself saying his name was Rodney Priest, but he was not a priest in the church. His father, now dead, had been a dentist and his mother was a map maker. He said it was his father’s work that first interested him in science and he threatened to show us his false teeth but Mama forbade him. “Priest“ was his father’s and grandfather’s family name, so could not be changed even if he wanted to. In Bukoba the boy’s had called him “mchungaji” which means “shepherd of the flock”.

Mzee then showed us an unusual picture which was a copy of a famous painting in a museum in Paris. It showed a little French boy watching one of those spinning tops that goes round so fast that it doesn’t fall over but stands up on its point. We make similar ones at home in our village. Mzee asked us why he believed that boy was not just going to be a scientist when he grew up, but that he already was one. Was it because he was mzungu (white) or tajiri (wealthy, as his smart clothes showed) or the son of a fundi (a famous French jeweller)? No! it was because he was doing the two essential tasks of every scientist - looking and thinking! This got us pondering how we regard our students, even those who struggle understanding our lessons.

Mzee then wrote a list on the blackboard of words telling how he and Mama would describe the Africans they have been meeting every February giving these workshops since 2016. They said that in the main we seemed to be fit, strong, optimistic, brave, patient, friendly, resilient, humorous, dextrous, respectful, hard-working, innovative, imaginative, considerate, unselfish, polite, playful, thoughtful, community-oriented, family-focussed and team-spirited. They also considered us fair-minded, while at the same time sceptical which means hard-to-convince. These character traits, they predict, are what gives give us black Africans a great scientific future. Mzee gave us as much time as we wanted to discuss this list, then we were invited to disagree with their assessment. We were not surprised when no-one contradicted them and that was not for fear of appearing impolite. This is genuinely how we see ourselves in the modern world.

It was time to start our first experiment. Although not directly about coffee, it aimed to show the proportion of oxygen in the air and give an example of the importance of practical work. They had brought a demonstration of steel wool rusting in contact with moist air trapped over water inside a big test tube, called a boiling tube. They had set this up in their hotel the night before and brought it carefully in the taxi so the water did not spill nor the tube fall over. In twos and threes, we set up the same experiment for ourselves, making sure the level of water inside and outside the tube was equal at the start. We needed all the dexterity of our fingers to get it right. What would happen now and why? Mzee refused to give us all the answers straight away but made us think. Instead. What reaction might happen and what is air, a compound or a mixture? And why had the water in their tube risen only part way up and then stopped even though it had had all night to rise up to the top. We were promised we would be able to work out the answers after lunch but meanwhile we could think about and discuss the questions during the hour for lunch. There would not just be beef stew to “chew over“!

Meanwhile, in the lab, after doughnuts, we acted out a puzzle. Two brown paper bags each held 250 g of coffee beans from the famous Tanzanian “Elephant” estate near Arusha. They were labelled “L” and “R” for left and right. Everything about the growing and processing of the beans in both bags was identical; soil, rainfall, time of harvest, cultivar (variety of bush), gradient (steepness of slope), aspect (N,S, E or W facing), cleaning and curing (removal of dust and fruit layer). All these factors were controlled

and the same. The only difference, the experimental variable, was that one lot was roasted and the other unroasted, called raw or “green”. Which was which? Each delegate in turn closed eyes, held out hands, and made a decision. We were not to tell anyone what we thought, even after our turn was over. We could put one bag down while feeling the other all over, but were not to sniff them which would have been cheating! Then with everyone’s eyes open again it was time to vote. “Hands up those who think Left bag was roasted and the Right was unroasted.“ “Hands up those who think it was the other way round.” All fifteen of us delegates got it correct. Had we worked out that roasting causes expansion of the bean because of hot gases blowing them up like a balloon? Was that why we could feel that the roasted bag was bigger although the contents of both bags had been weighed out to have the same mass? If the roasted bag had a greater volume, what of its density? We wrestled with these key concepts and consolidated our grasp of them and we thought hard about what a fair test is and how to vary only one factor at a time.

Next, in pairs, we put ten roasted beans together touching in a straight row and repeated with ten unroasted. It was a bit awkward to get each bean pointing along the row and not sideways to the line but Mzee and Mama went round helping us get it right and we helped each other, of course. Seen from above with its flat surface down on the bench, a bean is oval not round meaning it is longer than it is wide. We then measured the length of the two rows with little rulers and calculated the % increase in one dimension (length) which happens when the beans swell. What would be the % change in volume? And what of density? Our maths skills as learners and teachers were being stretched like the beans cell walls.

It was time to do some actual roasting ourselves and Mama issued us with clean, dry boiling tubes. We lit the paraffin stoves that must suffice until we can get some Bunsen burners and afford the bottled butane gas for them and heated a few “green” beans. We saw them change colour to yellow then brown finally to black with a cracking noise. What was that liquid on the upper inside wall of the tube? Could it be water? The beans before heating felt completely dry so where had that water come from? We were invited to consider changes in molecular size during thermal decomposition and what the breakdown products might be. We felt our minds being stretched again like the cellulose and lignin in the vegetable cell wall under pressure from the hot expanding steam and CO2 . Mzee challenged us to work out why a big piece of meat shrinks when roasted while these beans expanded, but once again he insisted we use our grasp of concepts, those big ideas of kinetic theory and cell walls and membranes, to work out the answers. We also saw dark oily drops on the cell walls and learned about the lovely flavours in coffee oil and how it stabilises the froth, “crema” and “mousse” that Italians and French love so much in their tiny pricey little cups.

“Why? Why? Why?” was on our lips and those of our wazungu visitors all the time. Like children we pestered them and asked each other “Kwa nini” , “pourquoi” –that international word of science whichever language you speak. Mzee played a joke on my friend, a big man, pretending to prove to him and the rest of us how feeble he really was,

not a tough guy at all as he failed to grind some beans using the hand mill, while the smallest woman delegate, half his height, could easily grind hers. Of course, the trick was to give her some roast beans while he had struggled with tough unroasted ones with huge molecules of woody lignin, cellulose and hemicellulose not yet broken down by heat. Seeing and performing these experiments and later brewing (percolating) with ground roast and unroast beans helped me work out and still recall those three reasons for roasting – Flavour Development, Embrittlement and Solubilization. I can remember what we found out far better than if I had just been told it theoretically. What did we learn in teacher training? What was it -- “I’m told and I forget; I see and I understand; I do and I remember.” We were finding out how true that really is for science teaching

Mama told us that their friends in England had paid for our hot lunch of local food We ate nyama na ndizi (meat and vegetables) then fresh fruit and drank “soda” from bottles. Back in the lab we gathered round to see a coffee bean being burnt (fully oxidized) in the open air. This was different from when we roasted our beans in glass tubes because no air could reach them, since the CO2 given off had acted like an extinguisher. We saw the burning bean’s oils burst into flame. It was balanced on a loop of heat-resistant wire. Then the charcoal burn until nothing was left but white ash. We were each given a piece of universal indicator (UI) paper for testing the ash and saw the UI turn deep blue meaning that strongly alkaline non-volatile products like sodium, potassium and calcium oxides were in the ash as was confirmed by some flame test colours. We all know and love litmus paper but admitted the advantage of UI for showing the strength of acid or base and not just their simple presence. Maybe we can ask the suppliers to get some for us.

There was still lots to do before tea time. We saw how the trapped air, which had been in contact with the rusting steel wool, extinguished a burning splint, so it must be nitrogen. I felt my grasp of the ideas of limiting reagent (oxygen) and excess reagent (iron) being strengthened. There was still plenty of shiny, springy iron in the top of the tube but the oxygen (limiting reagent ) had run out. Only some of the steel wool had turned to brittle rust.

We had a couple of non-science teachers among us delegates, “Senior” James is our economics teacher and Omari teaches business studies and entrepreneurism. They helped our discussion of the worldwide coffee trade and reasons for the poor return which farmers get for their crop, often less than 5% of the price paid for an expensive cup in Europe, can you believe. We realised that coffee has to be exported as green beans because once roasted, it quickly loses its freshness, quality and value. We learnt that the four “Enemies of Coffee” are air with its oxygen, moisture, high temperatures and too much time. If coffee is exposed to these, it will be spoiled. We saw and smelt some horrible old smelly coffee which was years old and had suffered from all four enemies. It smelt like a he-goat! Mzee called it his “Chamber of Horrors”! We learned a little bit with photos and description how “instant” (soluble) coffee is made and I was amazed to learn that much of the high technology equipment for making it is manufactured in Denmark in cold northern Europe which is far too cold to actually grow any coffee. The process engineers in Europe and North America who design, build and use this large-scale equipment along with the roasters, pocket most of the profits from the value added. Perhaps building up the market locally for better quality coffee for us Africans to drink ourselves here in the producing countries will improve the situation. Apparently, this is starting to happen in Ethiopia. As our nations become wealthier so we shall keep more of the profit but Mzee predicted that he and Mama could be 100 years old before there is much improvement! Perhaps local markets here for other coffee-based products, like that coffee-flavoured yoghurt which pupils at Nyakasura School in Toro, Western Uganda are developing, will help more profit stay here on the equator. We must dream and work for a better future for our children, even mine when my sweetheart and I marry.

I did enjoy making that model of a caffeine molecule. We used wooden sticks and coloured modelling clay. Mzee sang a song to himself , CNCNC=CNCN as he drew the structural formula so we built the two rings of atoms and fused them together getting the atoms and coloured clay balls in the right places . We saw how caffeine is similar to some neurotransmitters such as acetylcholine and understood why it stimulates the central nervous system whereas alcohol depresses it besides damaging and even killing liver tissue. Because I like teaching organic chemistry, I am looking forward to the chance to give my students practice in checking that each atom has the correct number of bonds – “four to carbon, three to nitrogen” etc. “Practice makes perfect” we are told.

We had a short simple piece of pedagogy (theory of effective teaching and learning) from Mzee when he showed us his Grasp => Hold =>Use idea for getting the attention of a class. He said it is not enough just getting their attention: you must reward them by putting their effort of paying attention to a clear worthwhile purpose. That made sense and perhaps I will try applying the idea in my lessons. It is easy to remember what to do. Just write the letters H U G round in a circle, clockwise or anti clockwise, either way it does not matter, and then go round starting with G.

I did find it quite hard understanding what Mzee would like us to do next to help our careers. I know our government wants our teaching to be more relevant to life here and now, more practical and useful and less purely theoretical. The ministry tells us it will be adjusting the syllabus to reflect this wish. Mama gave us each a list of another 99 industries other than coffee processing which have factories here in East Africa or whose products are on sale here. I realised my students and I would need help choosing the most suitable industry for us, one they are really interested in and which I can investigate myself and develop the experiments about. On the back of the list of factories was a choice-maker diagram showing a flower with eight petals representing eight different “abilities” which ought to be features of our project. Even if we are not certain about all 8 concerning our chosen industry, it should help us pick the right one. I especially thought about the “memorability” petal, wondering if finding out about bati (corrugated iron for roofs) for example can make those big ideas of reactivity of metals stick more strongly in my learners’ minds.

During tea we had a chance to fill in Mzee and Mama’s brief survey on why we became science teachers and who influenced us in that decision. They are also interested in what daily problems we encounter and what makes us enjoy the work. This is the plus and minus, the ups and downs of being a teacher, you could say. They are interested in why a person becomes a science teacher and why some teachers persist with it, even when the job becomes really hard, while others quit They promised to tell us the results of this research which they are conducting here and in other countries in East Africa. They tell us that, naturally, they will share these ideas with our government since the ministry of education has given them permission to come here for this purpose.

We all took photos of each other and I was pleased to receive my certificate of attendance at the end of a busy and useful day. If I think of trying for promotion sometime, I will definitely show the certificate as evidence of my continuing professional development, what we call CPD. The Head came to thank our visitors and they told us how much they had enjoyed being with us and thanked us for being hosting the workshop. They gave our school a small electronic balance accurate to a hundredth of a gramme for delicate experiments. Although they looked weary at the end, they seemed pleased with our response and we promised to keep in touch. We told them we hope they live long enough to come again but if not we reckon their sound ideas about good teaching practice must be their legacy. Kwa heri ya kuonana, “Goodbye and we hope to see you again.”

Clearly, this version of what we do in East Africa is fictitious in the sense that it is not put together by one actual delegate but by me. Perhaps it is a bit idealised, bordering on romanticised, even. Nonetheless, it is factual, truthful, and not exaggerated and based on spoken comments and emails we have received from among the teachers who have attended our workshops. In Burundi, for example, 15 schools are joining together to try out soap-making and find out about that industry. When we are registered with the UK government’s Charity Commissioners it will be easier for us to give some money to help this project.

We have had the pleasure and privilege of giving these workshops more than two dozen times in 5 different East African countries to many more than a hundred delegates in total, while building up some heart-warming friendships. We plan to continue doing the same while the blessing of health and strength allows.

R H P Colerne, Wilts, England 27 / 8 / 23

Through the eyes of a delegate

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