Toast Challenge
By Prof Tony Greenfield
Your feature about toasters (March, 2005) warmed my heart, brought a sparkle to my eyes and a surge of nostalgia throughout my entire being.
I sat in my garret room in Chalk Farm, 55 years ago, a fork in hand with a slice of bread on its end, in front of a gas fire: a mining student trying to survive in a fierce winter. I had just read, in the evening newspaper, that a Harvard student had been awarded a PhD for his research into the shaking of hands. “If he can do that”, I thought, “then there must be something for me”.
I watched my toast and was inspired. The whole world will sing my praises, I was certain, if I could solve the problem: What is the optimal thickness of toast? Just think about it and list the many variables. What are the response variables, those by which you judge the results: brownness, crispness, taste, firmness, crumbliness, dental sensitivity, swallowability, the smell? What are your control variables: thickness, density, flour type (proportions if mixed), moisture content, temperature of the gas fire, toasting time, and distance from the gas tire? What are the concomitant variables, those covariates that you cannot control, such as ambient temperature and humidity (certainly not controllable in a Chalk Farm garret), fatigue and shakiness after a game of rugby and three pints of beer?
The research program must attract great funds from government and industry; it must lead to many published papers and, when the Swedish king heard the solution, a Nobel Prize.
I made some notes and wrote a brief essay about the mysticism of toast consumption, adding some remarks about the variations of marmalade. The dean of the school of mines was not impressed. He also said that I spent too much time playing rugby, running round tracks, drinking beer and enjoying the company of girls. I thought that was why I was there but he asked me to leave. Research facilities were no longer available.
Three lives later (technical journalism, industrial statistics, medical statistics) and retired, I make my own bread in a Kenwood home baker. It’s lovely: brown, malty and big. So big in fact that slices wont go in the toaster. Oh yes, the world has moved on. Students live in cushy halls of residence and not in garrets. They don’t have gas fires, or toasting forks. But they buy square pan baked white bread, sliced and wrapped, just like those illustrated in your feature of March 2005. And the toaster is made to match, just like the one you illustrated.
Slices from my home baked loaves are about 18 cm by 13 cm. This is the same size as slices from large loaves bought at the local bakery. So far as I can discover, there is no domestic toaster on the market that will take slices that size.
Apart from that, domestic toasters are generally unsatisfactory because they do not toast evenly, often one side is toasted more than the other, and the timing needs to be changed according to the moisture content of the bread. The toasting intensity scale goes from 0 to 8 but if you set it at 3 even the most moist of bread will burn. It’s like having a speedometer scaled to 200 mph in a car that is not permitted to go faster than 70 mph. Also, the scale is just a timer and the user must judge what setting is needed for the finish of the toast according to his assessment of the bread. The scale should have three levels: light, medium, dark. The toaster’s sensors should determine when to stop toasting to match the settings.
These are problems that could be solved with a little technical thought. I put them to Kenwood
who assured me that their toasters are made to take the size of a supermarket brand of loaf and that, since their toasters have central elements, the heat in this area will be more extreme than in the area around the outer element. When cooking only one slice of toast, the heat can not be evenly distributed and therefore it is possible for one side to brown darker than the other. ‘Can not’! This is not acceptable. It is a clear challenge to all good scientists and development engineers. There must be some of your readers who are able and willing to show these cavalier toaster makers what made Britain great.
