I’ve loved to bake ever since I was a little kid. The smell of freshly baked bread sent me straight to my own little heaven. But there’s always been a nagging thought that I kept asking my mom. Aren’t we using the same ingredients over and over again? How are there so many varieties coming out from the same ingredients? Well, my inner foodie combined with science geek delved into food science and man, was I blown!
There are only six basic ingredients that go into the making of any bakery product – flour, fat, sugar, eggs, water, and leavening agents. Under the right conditions, you can make bread, pizza base, cake, macarons, bao, cookies, and even puff pastries! How? The secret is in the method of preparation. In this article, we will take a look at how cakes are made and appreciate the science behind the five essential steps of cake making.
The baking of a cake usually starts with mixing the fat and sugar. This process is known as creaming. When you mix fat and sugar at high speeds, air is incorporated, producing the high volume and low density that makes your cake super light and fluffy (Figoni, 2010).
Eggs are a rich source of protein, fats, vitamins, and minerals. The main role of the egg is to provide structure and stability to the cake. It does so by creating an emulsion. Fat and water do not mix, so eggs bind them together and prevent them from moving apart. Proteins in eggs coat air bubbles, adding strength and preventing collapse. The protein film is further strengthened when the heat in the oven causes the egg proteins to coagulate. Fat in egg yolk contributes to flavor.
Flour contains gluten. Gluten is a storage protein found in the seeds of cereal grains. It is a combination of two proteins: gliadin and glutenin. A unique property of gluten is the ability to provide elasticity and strength. This enables the cake to expand while wrapping tightly around air bubbles to prevent them from collapsing.
Adding Leavening Agents
Baking soda and baking powder are added to cakes to help them rise. Baking soda is technically called sodium bicarbonate. Baking powder is a mixture of baking soda, a weak acid (such as cream of tartar), and cornstarch. Baking soda is an alkali, so when it reacts with an acid, it produces a salt, carbon dioxide, and water. The carbon dioxide gas gets trapped in the cake batter and helps to lighten and further aerate the cake (Book, 2015).
We have finished preparing the cake batter! All that’s left is to pop the pan into the oven and wait. An entire network of events follows.
- Oven temperature rises
- Moisture turns to steam
- Gas bubbles expand
- Cake volume rises
- Gluten traps gas and holds the structure of the cake
- Egg and gluten proteins denature
- The protein film around the air bubbles gets stronger
- The cake takes on a permanent shape
- As the temperature increase, the cake turns brown due to Maillard reaction – A chemical reaction between amino acids and reducing sugars (Ellis, 1959)
- Maillard reaction produces complex baking aromas and flavors
You’re now left with a firm, moist, fluffy, aromatic golden goodness. Baking is not just an art but a complex scientific process. Science is obviously not limited to wearing a white lab coat and being surrounded by smelly chemical reagents. If you can bake a cake, you are a Scientist.
- Figoni, P. I. (2010). How baking works: exploring the fundamentals of baking science. John Wiley & Sons.
- Book, S., & Brill, R. (2015). Effects of chemical leavening on yellow cake properties. Cereal Foods World, 60(2), 71-75.
- Ellis, G. P. (1959). The maillard reaction. In Advances in carbohydrate chemistry (Vol. 14, pp. 63-134). Academic Press.