A baking soda and vinegar volcano eruption or a fizzy potion are classic childhood science experiments and a great way to introduce the concept of chemical reactions. Washing-up liquid ( dish soap ) is often used to make the foam thicker and longer-lasting, but we recently discovered that egg white is a good alternative!
This Halloween themed investigation compares dish soap, egg white and extra water to discover which combination makes the best fizzy foam!

Egg White or Washing Up Liquid Investigation
You'll need
- 3 small containers
- Food colouring
- Water
- Tablespoon
- Teaspoon
- Washing up liquid/dish soap
- Bicarbonate of soda
- Vinegar
- Decorations - optional
Instructions
Pour a small amount of food colouring into each container.
Add the same amount of water to each container so the total amount of liquid is about one-fifth of the container.
Add a tablespoon of washing up liquid to one container, water to another and egg white to the third.
Add a heaped teaspoon of bicarbonate of soda to each and stir well.
Pour about 25ml of vinegar into each container and observe the reaction.
The amount of each substance isn't important, but you should add the same amount of each to each container to make it a fair test.



Results
We found that the foam without washing up liquid or egg white was thin and didn't last long. The egg white foam was the most foamy and thicker than the washing-up liquid version.

What's happening?
Baking soda and vinegar react to neutralise each other. Baking soda is an alkali, and vinegar is an acid. Carbon dioxide gas is given off, which is why the mixture fizzes upwards. When just water is used, the bubbles pop quickly, resulting in thin foam that disappears quickly.
Washing up liquid contacts surfactants, which lower the surface tension of water. They create a thick, stretchy skin around the bubbles, allowing them to last longer. Surfactants in washing-up liquid help break down grease and make the mixture more foamy.
Egg white is about 10% protein. When the mixture containing egg white is mixed, the proteins unfold and surround the bubbles of gas to form a stable network around them. This leads to the foamy mixture you see.
Learn more about egg white
Discover why egg yolks are left out of meringue with a fun science challenge!
Find out how to bake ice cream in an oven without it melting. A Baked Alaska is a delicious science based dessert!
Fun Facts about Egg White
Egg white is 90% water and 10% protein.
Egg whites give lift to foods such as soufflés and meringue, as when they are whisked, the proteins unfold and trap air bubbles!

Egg whites contain over 150 different proteins.
Egg white is cholesterol and fat free!
Science Concepts
Chemical reactions
Last Updated on October 19, 2025 by Emma Vanstone
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