The whole point of Incr-Edible science is that L10 learns the why of cooking, as opposed to the simple how. I want her to be able to take knowledge about one set of ingredients and apply the same principles to another set. I want her to understand substitutions and suggest some of her own. And eventually I would like to enable her to have the illusive gift of understanding food reactions well enough that she feels confident to experiment with her own recipes and create something entirely unique.
To this end I have been ‘testing’ their knowledge to investigate how much of the last two weeks of kitchen chemistry has actually sunk in and more importantly whether they were able to transfer their knowledge and apply it to another scenario. I did this by listing some ingredients on the white board and asking them to make an educated guess as to whether the ingredients would react with Bicarb. They needed to write a tick or a cross by each ingredient:
To be able to have an educated guess the children would each have needed to understand that to react with a bicarb it needed to be an acid. They obviously understood this but there were some items of food which they simply didn’t know whether they were acid or alkaline, for example Coconut milk. C10 came up with the great idea of looking at the ingredients on the back of the tin. That failed to be of any help – have you ever read the ingredients? Here was I thinking that coconut milk was, oh I don’t know, Coconut milk. It seems I’m wrong. It has many unpronounceable chemicals in it which confused more than helped the children. I asked how their guess could be a fairly sure statement of fact? T11 immediately said to test it, L10 shouted ‘universal indicator paper’ rather excitedly!! I asked what state each ingredient needed to be in, in order for it to be tested. C10 said liquid, with T11 being a little more accurate by saying in solution ie dissolved in water. Bingo! So they tested each one and rewrote their predictions in the table on the board:
I thought it interesting that they had different results for golden syrup and buttermilk. After it was over, I introduced them to the idea of contamination and how that might effect the results.
They then tested with Bicarb with the following results:
From their investigations, they found that Bicarb reacted and produced CO2 with Vinegar (very strong reaction), Citric acid, and buttermilk. I asked them what other foods might we cook which use Bicarb and the one reactive ingredient we hadn’t experimented with yet (buttermilk). I’m fairly sure they only knew the answer to this because we do so much cooking together, but they easily named pancakes, soda bread and scones. I asked what the acid/base reaction did in these cases. They knew it worked as a leavener. I asked which ingredients listed on the board could theoretically be used as a buttermilk substitute if they had none in the house and needed to make soda bread. L10 thought that milk with a pH of 7 could be mixed with an acidic like vinegar or lemon juice to make a buttermilk substitute. T11 asked if we could use orange juice which we always have in the house. I told them to make a hypothesis regarding all this and test it. Which they did.
To be continued…..