Creaming
This video loop shows the waves breaking at Glenelg Beach. As the waves break, they trap air bubbles in the water, making the white foam that rolls onto the shore.
The same thing happens during creaming - the first step in making a cake, where butter and sugar are beaten. Just like the breaking waves, the beating brings air into the mixture. The roughness of the sugar crystals helps draw the air in. The butter surrounds the air to form small bubbles. These air bubbles help make the cake light.
Coating
This video loop shows a surface being painted. This layer of paint can protect the surface from being damaged and make it stronger.
In cake making the eggs act like a paint. When the eggs are mixed in with the butter and sugar, they form a layer around the fat covered air bubbles. This egg coating protects the air bubbles from collapsing, especially when the cake is baked. When the proteins in eggs are heated they form bonds that make a rigid wall around each bubble preventing them from bursting.
Rising - stage 1
This video loop show the chemical reaction of an acid (cream of tartar) with an alkali (bicarbonate of soda) and water to produce, amongst other things, carbon dioxide gas. The video shows what happens when water is added to the two powders. The powders mix in the water producing a fizzing mixture. The fizzing is carbon dioxide being released.
Cream of tartar and bicarbonate of soda are two ingredients in the self-raising flour that is folded into the cake mixture. Even though the two powders are mixed together in the flour, they do not react until the cake is in the oven, where a combination of water and heat gets things going.
Rising - stage 2
This video loops shows balloons being blown up. The rubber of the balloon is made of many strands that can stretch out as the balloon is inflated.
Flour is made up of starch and proteins. Some of the proteins combine to create a mesh known as gluten, which acts just like a balloon. In the oven as the cake batter is heated, water becomes steam and carbon dioxide is formed. As these gases are formed, they expand the stretchy gluten and the cake rises.
Setting
This video shows an animation of a house being constructed. We can see the strong frame being assembled that hold the walls and roof in place.
As the cake heats further in the oven, at around 80 degrees Celsius, the proteins in the eggs and the expanded gluten become rigid, through a process known as denaturing. Just like the house frame, the cake now has a structure, which gives it a light and fluffy texture.
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