What kid doesn’t want to put something weird in the microwave and see what happens? Satisfy their curiosity with this fast, easy (and super clean!) science experiment with Ivory Soap.

Why Does it Need to be Ivory Soap?

It’s important to use only Ivory Soap for this experiment. When Ivory is manufactured, they whip a lot of air into the bar creating little air pockets. The method was actually created by accident when an employee mixed the soap for too long and it formed air pockets throughout the soap. That’s also the reason Ivory Soap floats!

When you heat the soap in the microwave, the air in those pockets expands and makes the soap grow and fluff up. Other soap bars will not have as much air and will just melt. And while it doesn’t actually explode, it does look like it might at any moment as the bar at least triples in size and becomes a fluffy flakey white cloud-like blob. And you can even use it for soap afterwards if you want to keep it.

Step One: Get Ivory Soap

The first thing I did was order a 3-pack of soap on Amazon for under $5, because if I can avoid driving to the store, I will. I also wanted to have a couple extra bars so we could do it more than once and compare different blob effects.

Step Two: Stick Soap in Microwave

Unwrap your Ivory Soap and put it on a plate. We used a paper plate, but it won’t harm a regular dinner plate. Also, I’ve seen some people cut the soap into smaller parts, but I went with the solid bar first.

Step Three: Set for Two Minutes and Then Watch it Grow

Next set the microwave for about two minutes and stick around to watch the transformation. It will just spin around at first, then you see a little piece fluffing up, then it starts oozing out and growing like crazy.

Our soap stopped growing just after one minute, but it depends on the strength of your microwave. You don’t need to worry about it actually exploding, as it stops expanding at a certain point on his own.

It’s really neat to watch it grow! When you first take it out, it will be a little hot. Let it cool down, then try breaking it apart with your hands. This is the cleanest science experiment ever! The soap is still good to use afterwards if you don’t want to feel like you are being wasteful. You could sit it in a dish and have the most unique original soap sculpture hand soap in the neighborhood.

We had a lot of fun with this one and it’s definitely the only science experiment so far that left the microwave smelling better than when we started!