Cloud Soap Experiment

Cloud Soap Experiment, Wee Warhols, Ivory Soap, STEM, STEAM, Austin, science

If you are looking for a fun, easy, and cheap experiment…HERE IT IS!   It is so much fun to watch a bar of Ivory soap expand and cloud up in the microwave.  My boys were amazed.

All you need:

  • bar or more of IVORY soap
  • a comparison soap bar
  • a plate
  • a microwave



We started out testing if a bar of Dove soap and a bar of Ivory soap would float in water.  Baron predicted that they would both sink, since we usually use Dove around this house and had not used Ivory before.

Soap experiment, Wee Warhols, Austin, STEM, STEAM
Float or Sink?

The Ivory soap floated and the Dove bar sank.  Why is Ivory soap the only soap that floats?  And why does it expand in a microwave?  Well I will try to explain, but if you want an expert to tell you look here.

Then I wanted to cut the soap and look inside since Baron suggested that the Ivory soap may be hollow and that is why it floats.  (Good guess!)  I knew that my husband would not like us to use his fancy knives to cut soap, so I tried to break the Dove bar in half.  No way.  I tried to break the Ivory bar in half.  No problem.  Why was this?

soap, air pockets, Wee Warhols, experiment
Fluffy Air Pockets

As you can maybe see the Ivory soap is whipped when it is made and contains small air pockets.  This is why it floats!

Fun Part!- Put a bar of Ivory soap on a plate.  Microwave the soap for 2 minutes.  Watch it expand into a big cloud.  You will know when it is ready to take out.  (When using a microwave an adult should be present.)  When the cloud comes out, it will be warm.  I would advise waiting a minute before touching it.  My boys were not so patient, but no one got burned.

Wee Warhols, Austin, Ivory soap, experiment, STEM,
Growing Cloud of Ivory Soap!

So Cool!  They boys and I were surprised by the texture of the cloud.  You think it is going to be so soft, but it is more “papery”, as the boys described it.  Why is it so cool?  How does this happen?  Good ole Steve Spangler describes it like this- “This is actually very similar to what happens when popcorn pops or when you try to microwave a marshmallow. Those air bubbles in the soap (or in the popcorn kernels or marshmallow) contain water molecules. Water is also caught up in the matrix of the soap itself. The expanding effect is caused when the water is heated by the microwave. The water vaporizes and the heat causes the trapped air to expand. Likewise, the heat causes the soap itself to soften and become pliable.”

Well, of course I couldn’t stop there.  I had to bring that A into STEAM.  We got out our IKEA Ice Tray Molds and made some small soap forms.  -You have to do this when the “cloud” is pretty warm or it will all flake away.

IKEA, Soap, Molds, Austin, Wee Warhols
Formed Soap

One step further.. I had to bring Halloween into it, since I am obsessed.

  1. Heat the oven to 400 degrees.
  2. We put parchment paper on a tray.
  3. Find fun metal ghost cookie cutters
  4. Cook for 4-5 minutes
  5. Take out and pat down with something.  I used a set of chopsticks.
  6. Gently release.
  7. (They are not very strong.  FYI)
Halloween, ghost, soap, molds, Wee Warhols, Austin
Ghost Soap Molds

This is when I tricked one of them into taking a bath!

soap molds, Wee Warhols, Austin
SOAP that FLOATS

Oh yea, this post contains affiliate links, so I can send my kids to college or make 50 cents.

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