The last time I did science in the home with an 11-year-old, something happened that I can’t tell you about until the person whose chair it was has died. That is my abiding conclusion about the natural sciences: they stain, and don’t let anybody ever tell you they won’t.
Nevertheless, I have just undertaken science in the kitchen – nudged by a new book, The Kitchen Science Cookbook by Michelle Dickinson – because I have exhausted all the other ways of getting them to join me there. “This dish reminds me of evenings spent making bechamel with my mother, her apron brushing against my cheek as we spake of fat and its magical alchemy,” said every cookbook ever, but my parenting is much more in the Johnny Ball style: “Kids, you can’t teach them anything, but they learn everything from you.” I’m still in phase one: they will not touch my wisdom with a bargepole. C, 11, will enter the kitchen for anything that ends in a cake, but then we just end up with a load of cake. H, nine, will promise me the moon on a stick, then get distracted by a bee. T, 11, thinks it is emasculating to crack an egg. It wasn’t for the science that I tried a new tack; it was just for the company. Plus it was half-term, and you have to keep them occupied somehow.
Most of the ideas in Dickinson’s book are not edible, being designed to illustrate scientific principles: capillary action with kitchen towel and food colouring; transpiration, the process by which plants draw water upwards through their stems, with flowers and food colourings. Many of the experiments are also a bare-faced waste of perfectly good food, even sweets: catapults, to illustrate the transfer of different energies, potential to kinetic, from one object to another, are made with wooden skewers and marshmallows. You could eat the marshmallows afterwards, but that’s not your core business. There is a chapter called Edible Experiments, but unless you want to make a lot of slime – a viscosity experiment comprising condensed milk, chocolate syrup and cornstarch, for which “edible” is a strong word – you just have to commit to the science and forget the profligacy.
H and I started with “unicorn noodles” – a fancy way of saying noodles turned a kaleidoscope of pastel colours, purple, pink, a delicate turquoise, at least in theory. Enter cabbage, my undervalued old friend. When you boil up a red cabbage, you end up, predictably enough, with very purple water, pigmented by anthocyanin. It sounds more straightforward than it is; the colour is a sort of jolie laide, a beautiful jewelled violet from some angles, an evil swamp maroon from others. Curiouser, it looks like it’s morphing as you stare at it. To observe it in more stable conditions, use the water to boil up some clear noodles – glass or vermicelli – which will take about five minutes. Now you have purple noodles. But that is not all! Anthocyanin is only purple in pH-neutral conditions. If you add something acidic such as lemon juice, it will turn the noodles pink; if you add something alkaline (artichoke water, say), it would turn them blue and eventually green. We sprinkled acid over the noodles on a plate, to make a Jackson Pollock colour array. I had artichoke water, but it also had white wine and olive oil in it, which deadened the result a bit (the noodles went blue, but not a pretty blue). If you wanted something much tidier, you could dip them. This is mindblowing. It is an edible pH meter – if, that is, you like your noodles cold, doused in lemon, and a weird colour.
With T, I swallowed my parsimony and did some egg experiments, such as floating eggs (where you discover the principle of density by adding salt to a glass of water, and watching the egg float to the top. You can replicate this with stale eggs, but that would illustrate a different phenomenon, which is that air enters the egg over time, enlarging the air cell, which then acts as a buoyancy aid). There is a beautiful experiment with a boiled egg, where you light a candle at the bottom of a jam jar, put the egg on the lip and the air pressure sucks it in, spookily. Then there’s an eggs-and-vinegar stunt that takes four days, at the end of which the egg will bounce rather than break, which is, when you think about it, pretty incredible. I’m not sure what it proves, though: the book claims “chemical reaction”, but it seems like the average child could intuit that when you leave anything in vinegar for four days, it will be fundamentally altered at the end of it.
Finally, jelly worms with C, an experiment way too young for her, more suitable for a five-year-old, but she humoured me so sweetly that I felt like it was me being parented. Put jelly in some plastic straws. Leave it to set. Squeeze them out. Hey presto – they look like worms! It illustrates the protein chain of gelatine, which unravels when hot water is added, then coils back up as it cools. All jelly illustrates that; these just looked cool.
My grudging conclusion? The spirit of intellectual endeavour is its own reward, even when you can’t eat it.
