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Elephant Toothpaste


Presented by: Dr. Ashley Day and Noelle Hoyle


  • 1 tbsp Dry yeast (The video incorrectly states 2 tablespoons)
  • Dishwashing liquid
  • 3% hydrogen peroxide
  • Empty plastic bottle
  • Warm water
  • Measuring cups 
  • Measuring spoons
  • Empty cup
  • Location for the activity that can tolerate spills – We suggest the bathtub, sink, or an outdoor location


More experiments


In this activity, you will be using chemical reactions to make elephant toothpaste.


Caution: hydrogen peroxide can irritate your eyes.
Make sure to handle with care and wash your hands after using.
While the result of this activity looks like toothpaste, it is NOT. Do not eat!
Place your plastic bottle on a tray or tub so that it is easy to clean up.
The chemical reaction gives off heat, handle with care.


  1. Place an empty bottle in a bathtub, tray, or on an outside surface.
  2. Measure 1/2 cup of hydrogen peroxide, and carefully pour it into the bottle. Hydrogen peroxide (H2O2) kills cells. So handle with care.
  3. Add a big squirt of dishwashing liquid into the bottle, and swirl gently to mix. Make sure to save a drop of dish soap for the Pretty Penny chemistry experiment.
  4. In a measuring cup, mix together one (1) tablespoon of yeast and three (3) tablespoons of warm water. Stir for about 30 seconds. 

    Yeast are single-celled fungi. Fungi are eukaryotic organisms that absorb nutrients for energy. These yeast are dominant and adding warm water rehydrates and allows them to function as active cells.

  5. Pour the yeast mixture into the bottle. Then quickly step back, and watch your reaction go!

Observations and results

  • What happened?
  • How long did the reaction last?

Yeast have an enzyme, catalase, that can quickly break down hydrogen peroxide in water and oxygen gas  (2H2O2 → 2H2O + O2). When the oxygen is released, it changes the soap to FOAM.


  • Wash the foam down the sink when you are done with the activity
  • Discard all materials in the trashcan