This is probably one of the quickest science experiments you can do, while receiving one of the biggest “WOW” factor from your kiddos!

Basically, all you need is a bar of Ivory brand soap and a microwavable plate!

As with a lot of our experiments, we like to do a sink or float test. Ask your child to predict whether the bar of soap will sink or float, then put it in a bowl of water to test it out.  We tested another brand at the same time:  the Ivory brand floated while the other brand sank.

Exploding Ivory Soap Experiment

Sink or Float Test

Check out some interesting facts we found on Ivory soap and and the history behind why this brand of soap floats!

Now, let’s prepare for the fun experiment!  Place your Ivory bar of soap on a microwavable plate. With a knife, cut the bar of soap into pieces. Then pop the plate into the microwave for 1-2 minutes and see what happens!  (Note: Microwave ovens vary, so keep an eye on it. We left our soap in for exactly 2 minutes.)

Exploding Ivory Soap Science Experiment

Cut bar of soap into pieces before putting in the microwave

Take it out of the microwave, and get ready for the “Whoooaaaa!” from your kids!  The boys were so excited to see the soap explode! They could not stop giggling!  (Warning: the soap is quite hot to the touch when you first take it out, so be careful. The good news is that it cools down rather quickly so the kids don’t have to wait too long!)

Exploding Ivory Soap Science Experiment


This happens because the bar of soap has air bubbles in it.  When heated up, it expands! Scientist Steve Spangler explains this experiment in detail and even has a great video that goes with it.

Exploding Ivory Soap Science Experiment

So fun to touch and feel!


We tried the same experiment using Olay brand soap, and as you can see, we did not get the same result!

Exploding Ivory Soap Science Experiment

The boys were scratching their heads a bit here…

And there you have it!  Isn’t that so much fun?!  A quick, simple, and super fun science experiment — and all you need is a bar of Ivory soap!



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