This week we have been learning about thermal insulators (materials which stop heat from passing through) and thermal conductors (materials which allow heat to pass through easily). As part of our work, we wanted see thermal insulation in action and what better way than by baking ice-cream!
We made a Baked Alaska (cake and ice-cream wrapped in meringue). First we made a base of Madeira cake, then whipped the egg whites and sugar to make meringue. (We also tested the meringue was stiff enough by holding the bowl upside down over someone’s head)
Next, the we covered the sponge base with the sliced up block of ice cream and smothered over the meringue. After three minutes in a very hot oven, the meringue was golden brown.
But what of the ice-cream? We were all amazed to find that inside, the ice-cream was intact and still frozen!
It tasted pretty good too.
Meanwhile, we left some ice-cream out of the freezer (and didn’t even put it in the oven) and after just a few minutes, it began to melt – so we have proven that meringue is an excellent thermal insulator… but it’s probably not a good idea to try to wear it as a coat!
