Want the secret to brilliant baking? It’s all in the chemistry of cake…
Baking involves an abundance of chemical interactions. From air bubbles in the mix which expand and make the cake rise, to the stretchy gluten. Learn how all the science comes together to produce a tasty treat here…
1. Mix sugar, flour and butter/margarine
Sugar is added for sweetness while butter or margarine is added for moisture. Sugar and fat interact to create air bubbles which help make the cake fluffy. Refined white flour is usually used in cake mixture, because it is light and creates a better texture. The sugar melts into the flour at 186 degrees Celsius (367 degrees Fahrenheit), when in the oven.
2. Break the eggs
When the cake mixture is beaten, air bubbles are trapped and they help to make the cake light and airy. Eggs are critical at this point because unless beaten egg is added, the fat in the mix collapses and the air escapes during cooking. The egg white creates a film around the air bubbles, and as the cake rises during baking, the film forms a rigid wall which fixes the shape of the cake.
3. Add baking powder
Baking powder contains sodium bicarbonate, the acidifying agent cream of tartar, and a drying agent (usually starch). When sodium bicarbonate is combined with moisture and an acidic ingredient, it produces a chemical reaction so bubbles of carbon dioxide are created. The reaction starts as soon as you mix the ingredients, so you need to bake cakes containing bicarbonate of soda immediately.
4. Mix everything to a gloopy consistency
As you stir the mixture, the ingredients start to interact. The fat and sugar mix to create bubbles, and the baking powder is activated by the moisture from the butter/egg, releasing gas to make the dough rise. The egg binds it all together and starts to form a film around the air bubbles, while the spread ensures the cake remains moist.
5. Cook it
Spoon the cake mixture into a tin and place in the oven. The combination of hot air trapped within the mixture, egg white protecting the air bubbles, and baking powder releasing carbon dioxide into the mix causes the cake to rise. Don’t open the oven door too early because if you let cool air in before the egg has fixed the shape, then it will stop expanding and contract. As a result, the cake will collapse!
How to make different types of pastry
Various types of pastry have slightly different ingredients and preparation methods. To make short pastry, for instance, you should mix the fat and flour, add water, roll the paste and cook at 180 degrees Celsius (356 degrees Fahrenheit). To make puff pastry, meanwhile, the dough is layered with butter to form many layers of fat and dough. During baking, the water in the dough turns into steam and rises, creating lots of flaky layers. Flaky pastry is made in the same way, but unlike puff pastry doesn’t require lots of rolling and folding. Other leaved pastries are made from a paper-thin sheet of dough. Roll, stretch or press to create these sheets. Before placing them in the oven, you must brush with butter or oil.
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