It's the season for baking, but have you ever wondered what makes cakes and biscuits rise? It's all about the raising agent. This activity uses a basic cookie recipe and different raising agents to find out which works the best.
What is a raising agent?
A raising agent, also known as a leavening agent, is a substance used to create bubbles to lighten a mixture. Examples of raising agents are baking powder, yeast and steam.
If you’ve ever forgotten to add baking powder or baking soda to a cake, you probably didn’t get the light, airy mixture you were hoping for, and too much baking powder gives a funny taste. Baking is all about getting the amounts of each ingredient and the cooking time and temperature right for your bake.
It's a delicious, fun, festive baking activity for the whole family!
You'll need
Basic cookie recipe
225g unsalted butter at room temperature
110g caster sugar
275g plain flour/all-purpose flour
Chocolate chips - optional
Parchment paper
Baking sheet
Wooden spoon
Bowl
Potential raising agents to test
Baking powder
Egg white
Baking soda/bicarbonate of soda
Lemonade
Instructions
Preheat the oven to 180˚C.
Line a baking sheet with parchment paper.
Mix the butter and sugar in a bowl with the wooden spoon. Add the flour slowly until you have a smooth mixture.
Split the mixture evenly into four bowls.
Add a different raising agent to 3 of the mixtures and mix well.
The mixture without a raising agent is the control.
Add a handful of chocolate chips to each mixture.
Split the mixture into evenly sized-balls and spread them out on a baking sheet.
Bake in the oven for about 15 minutes.
Remove from the oven and compare each batch of cookies.
Remember to keep as many variables constant as you can.
- Use the same amount of dough for each cookie.
- Bake each batch for the same amount of time at the same temperature.
- Use the same amount of each raising agent.
If you liked this post, you'll love my Science Sparks Bake Off!
Last Updated on December 19, 2025 by Emma Vanstone
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