Anyone can cook but only the fearless can be great.
As a wise talking rat once said. But how to become fearless? Understanding the science behind cooking processes can go a long way in helping you banish any apprehension you might have about letting yourself loose in the kitchen.
I’ve decided to focus on baking for this blog because its precision, intricacy and general aloofness seem to rouse dread and fear in the hearts of many amateur cooks.
Aside from the extravagant decorations, baking is not nearly an art so much as a science. Understanding the processes behind baking (and, indeed, all types of cooking) can help transform you from a nervous wreck to a chef in command of the kitchen.
You can think of a recipe as a set of instructions for conducting an ‘experiment’ that others have repeatedly tested beforehand. A bit like many high school science experiments, perhaps. To become a real artist in your cooking, you must first think like a scientist, so you can understand the processes and then adapt them without disastrous consequences.
There are an infinite number of recipes I could explore, but I’ll start without one of the most basic and yet mysterious recipes: the classic sponge cake. Both the ingredients and the techniques are integral to a successful sponge, and I’ll examine both in the pursuit of a science-grounded recipe.
Cream together the butter and sugar
The first instruction for many cake recipes, this statement seems simple enough but can be fraught with difficulty. How do I know when to stop? What temperature should the butter be at? What type of sugar will give the lightest sponge? I don’t have all the answers but hopefully I can give you enough information to decide for yourself.
The aim of the creaming process is to trap gas bubbles in the cake mixture, which give the cake its lightness. The sugar crystals carry air on them and, as they are stirred, cut through the butter, so the air becomes trapped by a thin film of fat.
Creaming too much can destroy the structure of the trapped air bubbles, so the mixture becomes runny; you should stop once the mixture is noticeably paler or the texture becomes sloppy.
Caster sugar is the most commonly used sugar because it has small crystals compared to other types, so more air can be trapped on the crystals. Unlike granulated sugar, the crystals are small enough to dissolve so the mixture won’t become grainy.
Darker, softer sugars of varying hues like brown or muscovado sugar also work well, giving the cake a darker colour and less sweet taste. Their softness means they won’t cut through the fat quite as well, so less air will be incorporated in the creaming process, resulting in a denser cake.
The butter, or fat in general, gives the cake its rich texture, and makes the crumb more delicate. When the flour is later incorporated into the mixture, the fat surrounds the proteins in the flour with a thin film. This stops them from being further hydrated by moisture in the mixture, and so preventing the gluten strands from developing
Beat in the eggs
Eggs are used to give the cake moisture, bind the mixture and most importantly to stabilise bubbles created in the creaming process. The egg proteins encapsulate the air bubbles and coagulate during the cooking process to form rigid walls, permanently trapping the air in the cake’s structure.
Sieve the raising agents and the flour
Sieving itself only serves to evenly distribute the raising agents in the flour: it’s not strictly necessary but does help to distribute the air bubbles more evenly.
What’s the difference between all the different types of raising agents? Baking soda is pure bicarbonate of soda, an alkaline powder, NaHCO3 to be precise. Baking powder is a combination of bicarbonate of soda and an acidic powder, usually cream of tartar.
You can make your own baking powder by using one part bicarb to two parts cream of tartar, and it will be more powerful than a pre-mixed one. As baking powder sits on the shelf, the acid and alkaline powder can react slightly, reducing its effectiveness over time.
Self-raising flour already contains raising agents, but using plain flour and then adding your own helps you to control the exact ratio.
Gently fold in the flour
The proteins and starch in flour are crucial to the cake’s structure, and to give it its springiness. The starch reinforces the egg mixture, while the proteins join to form gluten. Gluten makes the cake springy but structurally sound, and allows it to expand during cooking.
High protein flour (‘strong’ flour) creates more gluten, which gives the cake a tougher texture. This is useful in bread-making, where a harder product is desirable, but is best avoided if you want a light cake.
Different types of flour such as wholemeal or rye give a different taste and also absorb more liquid. Substituting these in just means you’ll have to add some extra liquid, and the final cake will be slightly denser.
The folding process incorporates the flour into the egg mixture, while aiming to minimise destruction of the air bubbles. Overmixing can also join the proteins in the flour too much, forming more gluten so the cake is not as light.
Bake in the oven
Now all the hard work is done, and you can sit back and wait for the cake to cook. During the cooking process the gases in the trapped air bubbles expand and push out their floury walls. The starch in the flour absorbs moisture and the eggs coagulate so the cake’s structure sets, and the top of the cake browns.
If all that science and talk has made you hungry, here’s a Victoria sponge recipe, part of a series testing lots of different recipes to find the ‘perfect’ one. Its subjective of course, but I think its excellent inspiration to get experimenting and make your own perfect recipe.
The science behind why cooking makes things taste so good: https://theconversation.com/kitchen-science-from-sizzling-brisket-to-fresh-baked-bread-the-chemical-reaction-that-makes-our-favourite-foods-taste-so-good-58577
More details on the science of baking: