Want to bake a perfect cake? Then know your maths
TV cook and 'Kitchen Hero' Donal Skehan believes maths has a big role to play in good cooking
Published 17/10/2013 | 05:00
Next time you bite into a chocolate brownie or a fluffy sponge cake or when you sit down to tuck into your Christmas dinner, you should pause for a few moments to consider the maths and science that has gone into making them safe and tasty to eat.
I'm not just talking about how the sugar content in an overcooked brownie can be bad for your teeth or that an undercooked turkey can mean an unfestive visit to A&E!
Basic maths is hugely important when it comes to success in the kitchen. It wouldn't have been my favourite subject in school but I didn't realise how important it was at the time. There is a lot of science and maths in cooking. Every recipe I write is tested several times to make sure all the ingredients are in the right proportions, that the cooking times are right and so on. If everything isn't exactly right, it won't turn out properly.
When I hear people say a dish didn't turn out right, it is usually because they haven't followed the recipe, method or cooking instructions properly. I ask them if they put it in the right-sized tin, what temperature the oven was at and how much of each ingredient they used. You'd be surprised how often they get it wrong.
With baking, it's a question of weighing and measuring each ingredient and then adjusting for the number you want to make. Just divide or multiply the amounts to get it right. But you don't have to be too strict. You can throw in a splash of chocolate or whatever to flavour it as well. Baking is scientific but it's not that scientific.
The maths of the baking tin is important as well. People don't appreciate that if a recipe says to use a certain size of tin, then that's what they need. Too wide and the batter will spread too thin and cook too quickly and your cake will be ruined.
Maths is also very important if the recipe you're using happens to come from your mammy's cookbook or from a US website. Americans use Fahrenheit cooking temperatures and there is a big difference between them and Celsius – for example, 350 degrees Fahrenheit is equal to about 176 degrees Celsius. Forgetting to convert one to the other can be pretty disastrous.
Understanding temperatures can be absolutely critical in some parts of baking. If you're making caramel you have to be very careful with the temperature you are boiling the sugar at – 68 degrees, 76 degrees, and 86 degrees are three key temperatures. One will give you pretty rock-hard caramel and another will give you nice soft runny version.
And then there are pounds, ounces and grams. There are around 454 grams in one pound and 28 grams in one ounce.
Make sure to work out everything on a piece of paper before you start baking or you could end up with a very strange mixture. And then don't forget to work out the cooking time properly.
An unscheduled hospital visit may be the worst hazard of getting the turkey cooking time wrong, but it isn't the only one. There's probably nothing worse than your in-laws arriving on Christmas afternoon for dinner and finding that the bird has another three hours to go!
There's another very important use of maths in cooking: when you're shopping for food at Christmas, make sure to work out what you'll need and then shop around for the best value. Budgets are tight for everyone at the moment and doing the maths on the food supplies can save a lot.