Why doesn’t ice cream melt in a very hot oven?

This week in our Science club we were looking at why we can put ice cream in the oven without it melting. To prove this we made some baked Alaska.

First we made some meringue by whisking up egg white at high speed until they formed stiff peaks.  We then place a few scoops of ice cream on top of a slice of cake and completely covered the ice cream.

We then baked it at 220oC (very hot) for 10 minutes.  Normally ice cream would melt completely at these sort off temperatures, but when we served it the meringue was hot and the ice cream was still very cold. How is this possible?

When we whisked the egg whites we trapped millions of air bubbles in the mixture. Air is not a good conductor of heat and therefore the meringue mixture acts as an insulator protecting the ice cream from the heat of the oven. This is why fabrics that trap air keep us warm and why igloos provide people with shelter in polar regions.

As well as being a great insulator, meringue tastes great with cake and ice cream.