Elephant Toothpaste Experiment

Written By Jemile Nesimi-Hobson

Ingredients

  • ½ cup hydrogen peroxide (6%)

  • 1 tablespoon dry yeast

  • 3 tablespoons warm water

  • Liquid dish soap

  • Food coloring

  • Clean 16-oz plastic bottle

  • Safety goggles

Yeast is like a tiny helper that makes bubbles. When we bake bread, yeast eats sugar and produces carbon dioxide gas and a little heat. The gas gets trapped in the dough, making it puff up and turn soft and fluffy. In this experiment, yeast does something similar but with a twist. It contains an enzyme called catalase that breaks down hydrogen peroxide into water and oxygen gas. The oxygen gas rushes out as lots of foamy bubbles, and the reaction also makes the bottle feel warm.

So whether it’s bread rising in the oven or foam shooting out of a bottle, yeast’s special job is the same—making bubbles!

Procedure

  1. Put on goggles and pour hydrogen peroxide into the bottle.

  2. Add a few drops of food coloring.

  3. Add a squirt of dish soap and swirl gently.

  4. In a separate cup, mix yeast and warm water for 30 seconds.

  5. Pour the yeast mixture into the bottle.

  6. Watch the foamy eruption spill over — do this on a tray or washable surface.

Explanation

  • Yeast acts as a catalyst, breaking down hydrogen peroxide into water and oxygen.

  • The rapid release of oxygen makes bubbles of foam.

  • The reaction produces heat, so the bottle will feel warm.

Why is this experiment called Elephant Toothpaste?

It’s called “elephant toothpaste” because the foamy bubbles that shoot out look like a huge, colorful squirt of toothpaste—big enough for an elephant to use! Of course, no elephants (and no real toothpaste) are involved. The name is just a fun way to describe how much foam is made in such a short time.

Jemile Nesimi-Hobson