Tuesday, October 22, 2019

Puking Pumpkin Experiment

As my kids get older (particularly my boys), I'm always looking for fun activities that they will think are cool.  Gone are the days of play dough and preschool crafts and here we are making  puking pumpkins - where has the time gone :)

Here's what we did...

1) Put 1 cup of hydrogen peroxide and a few drops of food coloring (optional) into a container that will fit inside your carved pumpkin.  We used 12% peroxide (also known as 40 volume developer) that I found for $2.99 at Sally Beauty Supply.  Add 2 tablespoons of dish soap. 

2) In a separate bowl mix together 6 tablespoons warm water with two packets of active dry yeast.

3) Pour the dissolved yeast mixture into the peroxide/soap mixture, put the lid on the pumpkin and get ready for a CRAZY FAST and fun reaction.

We did the whole experiment a few times with different colors and we just hosed the pumpkin out in between.

This was seriously so much fun and the kids talked about it all weekend.  It would be a perfect idea to file away for the day after Halloween when you're done with your jack-o-lantern!

A couple of notes....

- we used SUPER STRONG hydrogen peroxide in order to produce such an "explosive" result.  This also meant that the foam was warm to the touch when it came out.  I'd make sure that you avoid getting this in your eyes because of the peroxide.  Also, you could totally do this with the regular hydrogen peroxide you have in your house - the result just wouldn't be as dramatic.

- We talked about the chemical reaction that was happening to make this a fun AND educational experiment and here's the info that we talked about (source):

The foam is made as the dishwashing detergent traps tiny oxygen bubbles created by the chemical reaction that is happening inside the bottle. The thick foam oozes out of the top of the bottle and looks like toothpaste when toothpaste is being squeezed out of its tube. The activity is called ’Elephant’s Toothpaste’ because the large stream of foam looks like toothpaste that is big enough for an elephant!
Hydrogen peroxide is a molecule made up of hydrogen atoms and oxygen atoms. It can be expressed using the chemical formula, 2H2O2. Under the right conditions, hydrogen peroxide will undergo a chemical reaction to break down into two parts, oxygen and water.
We can write out this decomposition reaction as a chemical equation:
hydrogen peroxide --› water + oxygen
2H2O2 --› 2H2O + O2
When a chemical that is made up of only one molecule breaks down into two different, smaller molecules, it’s called a decomposition reaction. This particular decomposition reaction is also an ’exothermic’ reaction, meaning it gives off heat. If you feel the sides of the bottle, the plastic should feel quite warm.
Yeast contains an enzyme called catalase. The enzyme is called catalase because it works as a ’catalyst’ in this reaction. A catalyst is a substance that speeds up the rate of a chemical reaction without changing its products. The yeast is added to the hydrogen peroxide to speed up the reaction. The catalase in the yeast speeds up the process of breaking down the hydrogen peroxide and thus produces oxygen and water more quickly. The oxygen gets trapped by the dishwashing detergent as many tiny bubbles.
- the foam is often called "elephant toothpaste" in case you wanted to google other videos or images or info to show your kids

Happy Tuesday, friends!!!


  1. My triplet grandsons would have loved this a few years ago!

  2. This is awesome! I have older teenage kiddos and always looking for fun activities. Thanks!!

  3. Did this with my class and they loved it! The pumpkin was huge, though, and I should have doubled the recipe


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