Elephant toothpaste is a favourite experiment at STEM Camp! But you don’t have to wait for summer camp to make it. Here, we’ve included the recipe and instructions for Elephant Toothpaste, as well as an explanation of the STEM behind the fun.
Explore the difference between chemical and physical changes while learning about the properties of yeast and catalysts with this activity.
Get ready for a super cool experiment that can be conducted over and over again!
Elephant Toothpaste Recipe and Materials
- 12-16oz plastic bottle
- 20-volume (6%) hydrogen peroxide liquid (also called developer)
- Active dry yeast
- Tablespoon
- Dish soap
- Warm water
- Safety goggles
- Mixing spoon
- Baking pan (or sink)
- Small cup or bowl
- Peppermint oil (optional)
- Food colouring (optional)
- Funnel (optional)
How to Make Elephant Toothpaste
Step 1
In the small bowl, mix 1 tablespoon of active dry yeast with 4 tablespoons of warm water. Use a spoon to mix the solution. Workout any clumps!
Step 2
Squirt about a tablespoon of dish soap, then a few drops of food colouring and peppermint oil into the plastic bottle. You can use a funnel to make this step easier! (Note that the peppermint oil and food colouring are optional but will make your elephant toothpaste look and smell minty fresh!)
Step 3
Add a ½ cup of the 6% hydrogen peroxide to the plastic bottle solution. Give the bottle a swirl to mix the solution.
Step 4
Put the bottle in the middle of a baking pan or sink. This will help control the mess.
Step 5
Make a prediction: What do you think will happen when you add the water and yeast to the solution in the plastic bottle?
Safety first! Make sure to put on your safety goggles before completing this step! Pour the yeast and water mixture into the plastic bottle. We recommend using a funnel so that you can pour quickly. The reaction will happen immediately so make sure to remove the funnel right away as well!
Step 6
Once the reaction slows down, touch the bottle!
STEM Q for You: Touch the bottle. What do you notice about the bottle? Why do you think this happened?
The bottle will be very warm! This occurred because as the hydrogen peroxide was broken down into water and oxygen, it released heat as a product. A reaction that produces heat is called an exothermic reaction!
Step 7
It is completely safe to touch and play with the elephant toothpaste, just make sure not to eat (ingest) it!
What is the Difference between a Physical change and a Chemical Change?
A physical change occurs when matter changes form (ex. ice melting to water) whereas a chemical change occurs when a new substance is produced.
Is this experiment an example of a physical change or a chemical change?
That’s right: A chemical change!
What Reaction Happens in the Elephant Toothpaste Experiment?
The hydrogen peroxide was broken down to produce water and oxygen.
In this experiment, the yeast acted as a “catalyst.”
In chemistry, a catalyst is responsible for accelerating a chemical reaction. In this case, the yeast helped hydrogen peroxide breakdown into water and oxygen very quickly.
Yeast acts as a catalyst because there is a certain enzyme in yeast called catalase. Enzymes are proteins that act as catalysts, thus quickening the speed of reactions. Catalase is very common and can be found in almost all living organisms when exposed to oxygen.
What Makes Elephant Toothpaste so Foamy?
The dish soap traps the oxygen from escaping and as a result creates the “foamy” bubbles.
