exploding soap experiment

• Skip to primary navigation
• Skip to main content
• Skip to primary sidebar

Last Modified: Jan 7, 2024 by Tara Gerner Leave a Comment

Exploding Ivory Soap - An Easy Kids Science Experiment

You know how something can be super fun and exciting until someone tells you that you have to do it? And then it loses all its luster and seems like something that is boring and hateful?

That's what happened to Super Science Summer.

My kids love science, and they begged me to let them do experiments all the time.

And then I decided to do a super cool 11-week series of summer science on my blog, and they balked. By week three, they were all like, " Do we have to do science again? " and " I would rather just watch tv, Mom. "

So Joe and I did a few experiments on our own and then quickly petered out, and that's why there hasn't been anything new for a while now. No involvement on the part of the people who were meant to enjoy all this sciencey summer fun made for a big zero.

Go with the flow, right? What else can I do?

I did, however, turn the tv right off. They haven't quit complaining about that, and it's been a couple of weeks.

So anyway, I have snuck in a couple of fun science activities in the weeks since they began boycotting all things interesting. They each went to science camp for a whole week (two different weeks, for their respective age groups), and they have done some vinegar and baking soda explosions out on the back porch in the evenings. Other than that, though, it's been a summer of doll houses and American Girl dolls and lots and lots of Usborne books.

Back to this particular science experiment . This is an oldie but goodie that I have seen over and over again in different books and on different websites.

• Ivory soap - Must be Ivory name brand, no other will work. Also, you will want at least a 6-pack because once or twice simply isn't enough.
• Microwave-safe plate

Instructions

• Unwrap soap.
• Place soap in the center of plate.

• Let the soap cool for a minute or so. Be careful for any hot spots. If there is any un-exploded soap chunks, they will be super hot. We removed those and tossed them back in the microwave to re-explode them.
• Remove soap from microwave and marvel at its shapes.

The Science

Microwaves make water molecules get excited, vibrate, and move really fast. Molecules that are moving really fast bump into each other a lot and move really far apart.

When the water molecules start moving fast and getting further apart, they stretch out the spaces in the soap and make it expand in all sorts of fun and interesting ways, as you see below.

Extend the Experiment

I asked my girls how we could change the experiment, and Allie's suggestion was to cut the soap into little pieces. I expected this to totally ruin the experiment, but the results were pretty cool.

I'm not going to tell you what happened. You'll have to do it and find out for yourself.

One last thing. I cannot get the smell of Ivory soap out of my microwave. It's not a bad smell, but it is odd to smell mingled with the scent of yummy food cooking. Just thought you'd want to know ahead of time.

More Elementary Aged Kids

Reader Interactions

No Comments

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Privacy Overview

Exploding Ivory Soap | Because Science Should Be FUN!

By: Author Charlene Hess

Posted on Last updated: July 15, 2024

This article may contain affiliate links. Please see our disclosure policy for more details.

Looking for info on how to do the exploding Ivory soap experiment? Check out this complete write up!

This exploding Ivory soap is a great example of a fun exploding STEM experiment . Preschoolers especially will love this engaging science activity.

Ivory soap is one of those classic household items that almost everyone has used at some point in their life. But have you ever stopped to think about what’s really inside of it?

Believe it or not, Ivory soap is made up of mostly air! In this blog post, we’re going to take a closer look at the science behind Ivory soap and find out why it explodes when you put it in water.

So are you ready to have some fun with science? This STEAM activity for kids is a great place to start!

Let’s go!

Easy Navigation

What Is Ivory Soap Made Of?

Ivory soap is one of the most recognizable brands of soap on the market. It has been around for over 140 years and is known for its characteristic white color and simple, clean scent.

But what is ivory soap made of? The answer may surprise you.

Ivory soap is actually made from a couple of different kinds of oil – palm oil and castor oil. These oils are combined with sodium hydroxide (lye), water, and a few other inconsequential ingredients(magnesium for example) to create what is called “soapstock.”

This soapstock is then mixed with air and passed through a machine that transforms it into the familiar bars of Ivory soap.

Finally, the bars are stamped with the Ivory logo and packaged for sale. So there you have it – the next time you reach for a bar of Ivory soap, you’ll know exactly what’s inside.

Now the question is what can we do with this information?

What Are Some Other Fun Science Experiments For Kids?

Before we dive into the exploding Ivory soap science experiment, be sure to take a look at these other fun science experiments and STEM activities for kids!

• STEM activities for preschoolers
• STEAM activities for elementary
• The Ultimate Collection of STEM Activities

If your kids like science,they are sure to love some of these amazing activity ideas!

Scientific Method Worksheets – Free Download

Before you move on, we’ve got some free scientific method worksheets for you to download and enjoy. These printable worksheets are useful for any science experiment, science project, STEM challenge, or STEM projects your students might be engaging in.

Turn every science project and STEAM activity into a thought-provoking STEM challenge. Plus give left brain and right brain kiddos alike a chance to utilize their strengths and improve their weaknesses. Get yours now!

About The Exploding Ivory Soap Science Experiment

Whoever decided to put soap in the microwave is amazing! Putting Ivory soap in the microwave will be an experiment that you and the kids will talk about as it’s simple and exciting to watch.

If you aren’t sure you have any Ivory brand soap around the house a quick way to check is by putting it in a bowl of water. If it floats, you have Ivory soap. 

How To Make Ivory Soap Explode

Your kids are going to love this quick and easy science experiment!

• Ivory Brand Soap
• Microwave Safe Dish

Instructions

• Unwrap soap and place it on a microwave-safe dish.

• Watch the soap as it “explodes!” You will see this start to happen within the first 10 seconds or so.  

• If you want to touch the soap be careful, it is warm, especially underneath all the “fluff.”
• When we were done with the soap “fluff” the kids used them in the shower, it was fun and they were squeaky clean.
• We looked at Ivory soap and how it was different from other soaps by putting it in water first to see if it floats compared to other soaps. Ivory soap floated while the other soap sank.
• After we had the Ivory soap in water we put it in the microwave to see if a wet Ivory soap would “explode” more compared to a bar of dry Ivory soap. We notice the wet Ivory soap grew faster and larger than the dry Ivory soap. 
• The soap is brittle and fragile to touch after it comes out of the microwave so if you are wanting it to stay whole be gentle.
• You can stop the microwave and move the soap “fluff” if it is getting too big or about to fall off the plate.

Recommended Products

As an Amazon Associate and member of other affiliate programs, I earn from qualifying purchases.

Did you try this yourself?

Please leave a comment on the blog or share a photo on Facebook

Follow-Up Questions And Activities

Use the following questions and activities to keep the learning going!

•   What would happen if we microwaved other types of soap?
•  What happens if you microwave wet or dry soap?
•  What is so different about Ivory soap than other soaps?
• Learn about the soap-making process and make your own soap. Consider exploring a lesson on entrepreneurship.
• Look at Ivory soap and how it is made, try and recreate it. 
• Measure the height and weight of your soap before and after the microwave.
• Conduct an experiment using the scientific method (and these free scientific method worksheets ) where you compare and contrast various brands of soap. Compare things like explosion rate, short-term effect on the skin, long-term effect on the skin, smell, effect on hair, etc.

Why Does Ivory Soap Explode In The Microwave? The Science Behind Exploding Ivory Soap

Ivory soap is made with air bubbles therefore it is lighter than other soaps and reacts differently when heated up in a microwave.

Since Ivory soap has all of those air pockets when it is heated up in the microwave, water molecules inside the air pockets cause it to expand or “explode” and make this amazing project!

Free Printable Exploding STEM Project

Want a free project sample? Sign up to have one of the projects sent to you so you can get an idea of the type of experiment guides you’ll get in our STEM Made Easy Digital Subscription!

• Recent Posts

• Mad Libs Word Lists: Funny Adjectives, Adverbs, Nouns, & Verbs - December 9, 2024
• 44+ Whole Family Experience Gift Ideas For Christmas (or Any Time!) - December 6, 2024
• Exploring the Symbols of Christmas: A Free Unit Study and Lesson Plan - December 6, 2024

• Science Experiments
• DIY Projects
• AI Learning Hub

Exploding Soap Science Experiment

• October 5, 2018
• by ItsySparks
• ItsySparks , Mini Scientists

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.

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.)

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!)

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.

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

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!

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

Related Posts

8 Reasons Why Kids Should Science More [Infographic]

• October 9, 2018

Summer Fun Activities: Let it Snow!

• June 5, 2014

Easy Crafts for Kids: DIY Lava Lamp

Itsy Sparks

Dedicated to Igniting Young Minds, ItsySparks provides knowledge to foster learning, creativity, and exploration!

• Skip to primary navigation
• Skip to main content
• Skip to primary sidebar
• Skip to footer

Happy Hooligans

Crafts and Activities for Toddlers and Preschoolers to Tweens

Microwave Ivory Soap Experiment

Last updated on March 24, 2022

• Facebook 6.4K
• Pinterest 18.4K

Put a bar of soap in the microwave and watch it expand to 6x its size right before your eyes! The  Expanding Ivory Soap Experiment  is a classic science activity that will fascinate kids and grown-ups alike. 

The Microwave Ivory Soap Experiment is one of my favourite science experiments for kids because it’s so quick and easy, and it yields such fascinating results.  There’s almost no prep required, and you don’t need any fancy supplies.  All that’s required is a bar of Ivory and a microwave oven.

What happens when you put a bar of Ivory soap in the microwave?

Because of the high volume of air that’s whipped into it, when you microwave Ivory soap, it rapidly expands into a huge, fluffy cloud in a matter of seconds.

Who would’ve ever thought to put a bar of soap in a microwave I wonder?

I have no clue, but I’m glad they gave it a try because they discovered one of the best-ever science experiments for kids!

Can I do the Microwave Ivory Soap experiment with other brands of soap?

No, this expanding soap experiment should only be done using Ivory soap. The high air content in the Ivory brand is what makes the experiment work. If you use a different brand, your soap may not expand, and could even smoke and burn and ruin your microwave.

There’s no fear of that happening if you use Ivory bar soap.

Let me show you how you can do this experiment at home or in your classroom, and at the end of the post, I’ll suggest a few ways to use your fluffy, soapy results.

You’ll need 3 things to conduct the Ivory Soap Microwave Experiment:

For your convenience, this post contains affiliate links.

• bar of ivory soap (do not try this with any other brand of soap)
• microwaveable dinner plate
• microwave 

Getting started:

Before you begin, you can take a few minutes to let the children examine the bar of soap.  Use descriptive words as you take turns holding it, feeling it and smelling it.

Did you know that Ivory soap floats ?  It really does!  That’s because of the high air content I was telling you about earlier.

If you have an extra bar of Ivory, you could drop the spare bar into a bowl of water to show the children how buoyant it is.

Note: I wouldn’t wet the bar that you’re putting in the microwave.  I’m not sure how that would affect the science experiment.

Instructions:

Time needed:  3 minutes

How to Microwave Ivory Soap – Experiment

Unwrap your bar of Ivory and place it on a microwaveable plate.

Put your plate of soap in the microwave.

Run microwave on high for 1-2 minutes.  Today I set my microwave for 1:20.  You can’t really overcook your Ivory, but it will eventually reach a point where it stops expanding.

You’ll want to pull up a chair or stool for your child to stand on so they can watch the ivory expand right before their eyes.

It happens so quickly !  It’s fascinating!

The Ivory will start to expand at about the 15 second mark.  To see it rolling, writhing and expanding as if it were alive is really exciting!

When your microwave stops, remove the soap and examine it.

Caution!   The plate and the soap will be quite hot for a minute or so after being removed from the microwave.  They cool down quickly, but give the soap a few minutes before letting your children handle it.

Doesn’t your kitchen smell amazing?

Don’t worry, that smell should leave your microwave quickly, and it will not affect the flavour of any cooking you do.

You can always microwave a cup of water with vinegar or lemon juice added to get rid of the smell.

I personally love the smell of Ivory soap.  It takes me back to my childhood.  Ivory was the gentlest soap back when I was a kid, so we used it for years as children.  Because the scent brings back warm memories, I don’t mind that my kitchen smells like Ivory after doing the experiment.

If you think the soapy smell might bother you, open a window before microwaving your bar of soap.

Examining your fluffy Ivory soap cloud:

Once your soap has cooled off, it’s time to have some fun!

Let your children investigate how the soap has changed: what started out as a hard bar of soap is now a fluffy, crumbly powder.

Today, to let the children really explore the results of our experiment, I placed our puffed up soap in a large baking dish and the girls chopped it all up with paté knives.

They also rubbed it between their hands to crush and crumble it.  This is such an amazing sensory experience.  The soap is so smooth and silky.  It feels lovely, and it smells incredible!

Be sure to warn children not to put the powder in their eyes, nose or mouth.  It IS soap after-all, and it would sting the eyes, and taste horrible.

What can you do with microwaved Ivory Soap?

We usually do this experiment when it’s time to make a new batch of Homemade Laundry Detergent.   I make it with Ivory, Borax and Washing Soda.

The kids love helping me make laundry soap, and it’s a great way to use the results of this experiment.

Our favourite way to use our crumbled soap though, is for sensory play!

We grab a roll of toilet paper and some water and the hooligans whip up a clean mud, also known as  ghost mud or fairy mud.  It’s a moldable dough that smells wonderful and keeps the kids entertained for hours.

Why does Ivory Soap expand in the microwave?

To find out the scientific reason why the Ivory Experiment works, h ead over to Steve Spangler Science , and he’ll explain the science behind it.  

More easy, inexpensive experiments:

• Crystallized Beach Rocks
• Giant Homemade Bubbles
• 2-Ingredient Cloud Dough
• 2-Ingredient Ghost Mud
• 3-Ingredient Puffy Paint
• 5-Ingredient Homemade Watercolours

Get my latest e-book: Fizz, Pop, Bang!

40 hands-on, learning activities for kids ages 3-8. Recipes, experiments, art projects, printables and play ideas with links to 80 activities not featured in the book.

Download your copy today for just 9.99

Follow the Hooligans on Facebook

for FREE crafts, 

activities & recipes!

Jackie is a mom, wife, home daycare provider, and the creative spirit behind Happy Hooligans. She specializes in kids’ crafts and activities, easy recipes, and parenting. She began blogging in 2011, and today, Happy Hooligans inspires more than 2 million parents, caregivers and Early Years Professionals all over the globe.

Reader Interactions

jennifer Dyer

April 30, 2014 at 9:04 am

I absolutely love your web page! I’m always reposting! Keep up the great posts and pictures! I’m a mother of an 8 yr old son who has a form of autism, and I cannot say enough wonderful things about this group!!! But a huge thank you!

happyhooligans

April 30, 2014 at 1:33 pm

I’m so glad you’re enjoying my posts, Jennifer. I love that the things that I do in my small home-daycare are inspiring moms like you to get creative with your own hooligans! x

April 30, 2014 at 9:42 am

Could you put food color in it

April 30, 2014 at 1:31 pm

I imagine you could, Taylor.

May 2, 2015 at 10:21 am

Yes, drop the food color on the bar before you expand it and watch the magic!

May 3, 2015 at 8:26 am

Oh! That sounds cool. We’ll have to give it a try!

April 30, 2014 at 9:28 pm

I have found with kids, food coloring is dangerous! As it stains everything and anything. I stay clear of it since I made snake bubbles outside last summer with the kids wearing garbage bags over their clothes. Little did I realize it would take a couple of weeks to get the food coloring off their feet and the bubbles that blew onto the patio stained that too. No more food coloring for this grammie! (esp since the patio was not mine but their dad and moms! Yikes!)

May 1, 2014 at 2:03 pm

A couple of weeks? That’s some strong food colouring, Xubie. We use food colouring at least once a week here, both liquid and gels, and we’ve never had staining like that. My hands usually get the worst of it because I do most of the hard-core mixing, and they’re always clean by the end of the day. A few hand washes, and it’s gone.

April 30, 2014 at 9:52 pm

May 1, 2014 at 5:48 pm

Is there something special about Ivory soap? I’m in Australia and I have never seen it but would love to try this with my grand kids 🙂

May 1, 2014 at 8:39 pm

Yes, there’s a link near the bottom of the post that takes you to Steve Spangler Science’s website, where the scientific part is explained, Lizzy. It all centres around the Ivory soap, and why it’s different than other brands.

May 4, 2014 at 10:39 am

Be careful doing the ivory soap in the microwave. We had this done at an in-service training and the fumes coming from the microwave bothered those of us with asthma problems.

May 4, 2014 at 8:32 pm

Thanks for mentioning that, Faith. No one here has any respiratory problems, so I hadn’t thought to mention that it might be a problem for those who do.

Julie samples

May 14, 2014 at 10:22 am

I love love love your posts!

May 15, 2014 at 4:19 pm

is there a reason you can’t use any other type of soap, I wanted to know if I could try it with dove ?

May 15, 2014 at 5:13 pm

It’s the high air content that makes this work, Terrie. I can’t say if it will work with other brands. It could just burn. I really don’t know first-hand.

May 19, 2014 at 2:18 pm

I want to go home and do this experiment right now… my little one is only 9 months old, but I’m putting together an activity book with all of the experiments / activities I want to try in the future. This will be a favorite, I am sure.

Sheena Crain

May 27, 2014 at 12:15 pm

Sounds fun. My daughter will love this since she loves to be in the kitchen with me. I shared this to my page because pretty much all of the women in my family are into kids activities. Thanks and keep them coming!

May 30, 2014 at 9:54 pm

We did this experiment and loved it!!!! However it did bake my microwave stinky…would there be any advice on how to get the smell out? Did I over microwave the soap??? Yikes! !

May 30, 2014 at 10:11 pm

You might’ve, Michelle. My microwave has never smelled for more than a few minutes after doing it. How about microwaving a coffee cup filled with water and vinegar for a minute or so after Leave it to sit in there for a half an hour. Vinegar is good for absorbing odours. Then give the microwave a wipe, and maybe the scent will be gone.

June 3, 2014 at 10:53 am

Thanks for the advice!!!

July 4, 2014 at 2:01 am

HOW LONG DOES THE SOAP STAY FLUFFY???

July 4, 2014 at 7:16 am

It will stay that way until you crumble it up, Amy. Although it looks fluffy, it’s actually hard and solid, but can be crushed to a powder easily just by squeezing it.

Ann @ Such a Mama!

July 21, 2014 at 9:34 am

I microwaved just a few small pieces at the and of the soap’s life. It made a nice small cloud that was perfect to toss in the kids’ bath!

August 5, 2014 at 11:21 am

my soap didn’t expand that much so wonder if it made a difference if you let the bar sit out to harden or if maybe the soap was too old? I did use ivory soap.

August 5, 2014 at 7:45 pm

I would give it a try with a newer bar of soap, Jenn. I wouldn’t let it sit out to harden or dry out. I’m thinking the moisture in there would be a good thing.

September 6, 2014 at 7:51 pm

hola!!!! alguien sabe si para si funciona el experimento con el jabón blanco común para ropa? no conozco otro parecido en Argentina. Gracias.

September 7, 2014 at 10:45 am

Ivory soap suds was what my mom used to decorate the Christmas tree when I was little. It created a wonderful snow effect. It is a treasured memory now that brings a smile each time I think of it!

September 7, 2014 at 11:12 am

Ohhh, and it would smell so good too!

September 25, 2014 at 11:28 am

we always used Ivory soap on the Christmas trees too! But, you can only make snow for the trees with Ivory soap flakes… When they stop making those, that tradition died.

July 4, 2016 at 1:23 pm

I have never heard of it! Would you please post the recipe? That sounds great! (And we love the smell of Ivory too. My children and grandchildren are grown but I have some great grandchildren that would think Nanny is pretty special if she could do some of these things! I just found this site today and will use it often. Thank you so much for the easy and safe things to do with kids!

September 17, 2014 at 2:18 pm

I am doing a science experiment in my college physical science class for elementary teachers and I cam across this and I thought it would be a good thing to use for measuring also! You could measure how much foam it makes and I am also doing the experiment with Dial soap so I will let you know if other soaps do this also! Thank you so much for this it gave me wonderful ideas and all the links to other things you did I absolutely love those I so love being creative and doing crafty things and since I found your website and all your pages I will always just come here and find some fun things to do!!! Thank you so much again! 🙂

September 17, 2014 at 7:07 pm

I’m so glad you’ve found us, Becca! I’m so glad you’re enjoying my site! Do be careful using Dial. In fact, I actually wouldn’t recommend trying it with any brand other than Ivory because the air content isn’t as high. I’ve heard other brands can smoke and burn and actually ruin a microwave.

September 25, 2014 at 6:52 am

Okay this is a mediocre experiment at best. I agree that the effect is cool and I plan to do this with myself when I get home. But the whole point of a science experiment is to explain why something happens not just that it does. Do a little research and find out why the soap expands in such a way. The experiment itself is pointless unless you can teach your children something.

September 25, 2014 at 8:31 am

Gosh, i hope you’re teaching your children to be a little kinder and less critical of others, Aaron, but anyway… regarding your point: that’s the reason I’ve provided the link, near the bottom of my post, to Steve Spangler’s Science page – so you can find out the scientific reasons for the soap expanding. Perhaps you didn’t read far enough through my article to see the link, and just jumped to conclusions. In any case, even if I hadn’t provided the link, a parent could certainly research the science behind it themselves, before doing the activity at home. Gee, hope your day gets better, Aaron. Sounds like you’re off to a cranky start.

September 25, 2014 at 9:29 am

It’s a wonderful experiment! Nothing mediocre about it at all!! Love seeing the excited faces and squeals of delight screaming ” it’s magic!”. I love your posts ! Ignore the negativity!!

September 25, 2014 at 10:08 am

Thanks Julie! It’s a shame that some people are just so darn unhappy that they feel the need to pass their negativity on to others. I love your exuberance and zest for life! Thanks for lifting others up instead of knocking them down. x

September 27, 2014 at 2:00 pm

Science begins with curiosity. Science “magic” leads to science exploration. If you begin with hard core experiments you can lose the wonder. Keep exploring and sharing. This looks like a great place to start.

September 27, 2014 at 2:12 pm

Excellent point, Karen. Thank you!

Karen Carroll

October 1, 2014 at 1:11 am

According to Merriam-Webster.com, the definition of Science is as follows: sci·ence noun ˈsī-ən(t)s : knowledge about or study of the natural world based on facts learned through experiments and observation : a particular area of scientific study (such as biology, physics, or chemistry) : a particular branch of science : a subject that is formally studied in a college, university, etc.

Precious children learn as much from the loving care of the person who spends time helping them enjoy life as they do from a rigid set of steps toward a focus that does not hold their interest. This Ivory experiment has exciting factors that enhance the learning and the desire to seek further knowledge about the children’s observations. Impressionable minds remember what truly interest them. When education is bathed in genuine care and concern for the educated, questions will arise that prompt even more learning. Thank you for your “Clean Fun” suggestions, and for your comments on the reasons that we should use Ivory. True Science has qualities often unseen to the closed heart and mind, and, as with most of life’s lessons, there are appropriate levels of explanation. Your little ones are blessed to have you.

November 2, 2014 at 9:11 am

I agree with MJ – sad that Ivory Flakes are no longer made. When I couldn’t find any, I improvised by making my own. I used a vegetable peeler on bars of Ivory soap to make my own flakes. It whipped up pretty good and my daughter and I were able to make a small snowman. This microwave method sounds a little easier so I can’t wait to try it.

December 14, 2014 at 3:28 pm

Can you use imperial leather ivory soap or only the brand ivory soap

December 15, 2014 at 8:22 am

It’s the brand soap that you need, Julie. The one pictured in the post.

February 16, 2015 at 2:56 pm

My kid had a great time taking this project for science week at school.

February 16, 2015 at 4:46 pm

Cool! What a great one for science week!

May 6, 2015 at 1:07 pm

Hi can you use any soap or does it have to be ivory soap? Thanks Emma

May 6, 2015 at 1:54 pm

You definitely need Ivory for this experiment, Emma. It’s the high moisture content that make the expansion possible. Other soaps may just heat up and burn, and ruin your microwave.

June 14, 2016 at 2:54 am

This is amazing! Can I use any version of Ivory soap of does it have to be the original version?

June 15, 2016 at 10:55 am

I’ve only used the original, Sel. I imagine it would work with the others, but I’m not endorsing that as I can’t speak from experience. 🙂

Paul Callomon

March 26, 2017 at 9:15 pm

Ummm…my kid did this experiment and now my microwave stinks of soap. I cleaned it thoroughly, but apparently some of the soap-laden steam condensed in the vent and I will have to dismantle the microwave to get it completely clean.

March 28, 2017 at 11:17 am

I wouldn’t advise dismantling your microwave unless you’re qualified to do something like that. We’ve never had a problem with the scent lingering, but to neutralize any odours in a microwave (my son once microwaved a chocolate chip cookie for 3 minutes, and our microwave smelled like a bonfire), just put a cup filled with vinegar in, and microwave it for a minute. Let it stand in there until completely cooled. That worked for me with the cookie fiasco. 🙂

PATTY PARSONS

January 13, 2018 at 11:05 am

Love all your get ideas!!! Wondering if you can do cement objects like you do the beach stone?? Thank you!!

January 16, 2018 at 8:45 am

I’m assuming you’re talking about the Borax Crystal experiment and not this Ivory Soap experiment, right, Patty? You could try crystallizing a cement object. I think it would work. I’ve seen others use sea shells and those worked nicely.

Connie Behrens

March 13, 2018 at 10:03 pm

Does the ghost mud keep for a while in a covered container?

January 19, 2020 at 10:29 am

I do this when “making” diy laundry soap! Take fels naptha or zote soap, microwave as described here, then follow directions on WellnessMama or other sites for making homemade laundry soap. (Special tip: don’t want to lose your favorite laundry soap but don’t like the price? Mix the two! Same scent but much stronger!) Enjoy!

Patricia Fry

March 31, 2020 at 8:19 pm

caution: if you use an old bar of ivory soap it will crack and burn only. So disappointing but our bar was close to 10 years old.

December 21, 2021 at 6:22 am

Just stumbled on this idea and can’t wait to try it with my boys. I don’t usually but happen to have a large pack of this soap and the reason for having it is why I wanted to post! Another great use for the soap after it’s microwaved is to spread around in a garden or area being eaten by deer. We bought it to shave around our two baby trees to prevent these beautiful animals from tearing up the young bark. They deter them because they are very potent “human” smells!

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

This site uses Akismet to reduce spam. Learn how your comment data is processed .

Join My Private Support Network!

Our Most Popular Posts

• March 2021 3
• February 2021 15
• January 2021 12
• October 2020 34
• September 2020 17
• August 2020 16
• July 2020 30
• March 2020 5
• February 2020 13
• December 2019 14
• November 2019 21
• October 2019 15
• September 2019 3
• August 2019 21
• July 2019 5
• June 2019 18
• April 2019 6
• March 2019 14
• February 2019 18
• January 2019 7
• December 2018 12
• November 2018 8
• August 2018 3
• July 2018 17
• April 2018 17
• March 2018 15
• February 2018 2
• January 2018 3
• December 2017 7
• November 2017 5
• August 2017 2
• July 2017 3
• April 2017 3
• February 2017 5
• October 2016 1
• September 2016 2
• April 2016 1
• February 2016 1
• June 2014 4
• February 2014 4
• December 2013 1
• November 2013 2
• October 2013 1
• September 2013 3
• July 2013 3
• April 2013 1
• January 2013 2
• November 2012 1
• September 2012 1
• August 2012 2
• March 2012 1

Report Abuse

Growing A Jeweled Rose

• WAYS TO PLAY
• _Glowing Play
• _Sensory Play
• _Baby & Toddler Play
• _Preschool Play
• SEASONAL PLAY
• _Valentine's Day
• _St. Patrick's Day
• _4th of July
• _Thanksgiving

Ivory Soap Experiment

Ivory Soap Clouds

• 1 bar of Ivory soap (no substitutions)
• A microwave-safe plate
• A microwave
• Begin by unwrapping and examining a bar of Ivory soap .

• You can test the soap to see if it floats if you would like.  Can your kids guess how/why it floats?

• Rosie and Jewel guessed that the soap floats because it is hollow inside.  Not a bad guess!
• Have kids predict what might happen to the soap if cooked in the microwave .
• My girls looked at me a little strangely at first, hesitantly predicting that the soap would melt or catch on fire.
• Once predictions are made the experiment can begin!

The Ivory Soap Experiment

• Place 1 bar of Ivory soap onto a microwave-safe plate, and then place it into the microwave.

• Microwave the soap on high heat for 1-2 minutes , observing closely.
• Within 15-20 seconds you will notice the soap beginning to expand, a nd after just a minute the entire plate will be covered in a beautiful, soapy explosion!

Soap Explosion Exploration

• The answer is simple-  air pockets!
• Tiny pockets of air are actually whipped INTO the soap as it is made.  You can't see them, but they are there!
• These air pockets contain water molecules.
• When those molecules are heated by the microwave it causes the pockets of air to expand.
• As those pockets of air expand  the soap becomes fluffy  and grows in size. 
• The pockets of air in the soap cause it to be less dense than water, which makes it float!
• Place your soap clouds into a sensory bin with water, and kids will surely have a blast!

• Use your soap clouds to make ghost mud .
• Try putting other items in the microwave.  Do they expand?
• Marshmallows
• Rainbow Cabbage Experiment
• Skittles Experiment
• Rainbow Rain Experiment
• Oil & Water Science
• Storm in-a-Jar

Growing a Jeweled Rose is a site packed with fun and educational activities for kids. Read more about us or catch up with our favorite posts .

More About the Author

Crystal Underwood is the writer and creator of Growing A Jeweled Rose. She has worked extensively with children and strongly believes in the importance of play at the core of early learning. She is passionate about the early years and believes that childhood should be a truly magical time in life. For all the best kids activities connect with Growing a Jeweled Rose below!

you may also like

Snow Paint Recipe

No-Cook Cinnamon Ornaments

Toys In The Dryer

And Other Parenting Things - Minnesota Mom Blog

• Tasty Treats
• Parenting Advice
• Weight Loss
• About Jamie
• Guest/Sponsored Post Guidelines
• Advertising/Media Kit
• Local Events

Ivory Soap Explosion

I will be the first to admit that this ivory soap explosion is one super cool, fun science experiment! You’ll be just as impressed as your kids when you try it.

Here is what you will need:

• Ivory soap (It MUST be the brand name IVORY soap.  Other brands will NOT work!  It must be a fresh bar too.)
• A microwave

1)  Take one bar of Ivory soap and cut into half then in half again. Place one piece of the quartered soap in the microwave.

2)  Set microwave for 3 minutes (even though you won’t need that much time) and push start.

3)  Sit back and watch!

After about 90 seconds the soap will expand to about 6 times it original size!!! It won’t be too hot to touch either. Let it sit for about a minute or two and then remove it from the microwave and watch for your kids’ reaction.

I will admit that I wanted to see what would happen to a FULL bar of soap….learn from me…don’t do it…fight the urge! I had to stop it before it finished because my entire microwave was FILLED with Ivory soap!

The soap still works the same, so don’t toss it. I placed ours in my son’s bathroom and he loves to snap off a chunk each time he takes a shower.

Why does this Ivory Soap Explosion work? Ivory soap is whipped with air when it is made. When heated in the microwave, the air expands thus expanding the soap!

Please Share:

Oh my heck!!! This is the coolest thing I have seen ia a long time!!!! We’re so doign this! You are the best!!! I laughed out loud at your comment on doing an entire bar. I’m so glad you wrote that bcause I would have probably done a whole bar too =o) Seriously! So cool!!!

Um… that is simply awesome!

Posted abut this today! LOVED it!!!! Thank you so much!

What is ivory soap? Does it work with any bar of soap?

Anonymous–Ivory is a brand name of soap. It is sold in the USA, not sure if it is available in other countries. This experiment does not work with other kinds of bar soap. There is a lot of air mixed in with Ivory soap and that’s what makes this experiment work with it and it only.

NO way–my kids would love this 🙂

Why does this happen with ivory and not other soaps? Is it because of the chemical composition or the air? I know its the only bar that floats so I am assuming it has something to do with that. I am going to have to look it up because while we think it looks cool…curious minds need answers lol

I found you on Pinterest. Thanks so much for posting this. I can’t wait to try! I was curious and looked up why this works. It turns out that Ivory soap has air whipped into it during the manufacturing process, and as the trapped air expands when it’s heated in the microwave, it expands. Fun!

http://www.stevespanglerscience.com/experiment/00000053

It’s the air! Made in Cincinnati, Ohio (my hometown!) and one of the oldest bar soaps. http://en.wikipedia.org/wiki/Ivory_(soap)

Gotta try this with my three grandchildren..I know they each will want one! lol thanks for posting this..I love it!!

Ivory is a very mild soap. It is recommended for babies and people with sensitive skin.

ohhh wow i loved the comment… “what is ivory soap?” Lol i cant wait to try this with my boys! thank you!! Found through Pinterest

Amazing! Can’t wait to do this with my students!!!!

This is awesome! Gonna try to use it for some type of object lessons for kids’ church.

Saw you pin…totally cool! I unfortunately am allergic to ivory soap (breaks me out in hives), but I may try it still….my 5 & 3 year olds will get a kick out of it! Too cool. Thanks for pinning on pintrest!

Ohhh, my boys would LOVE this!! The look on your cutie’s face is adorable! My son has those same footie pjs… so cute. I’m your newest follower… hope you’ll stop by my blog and follow me too. Have a great weekend! xo, Laurie @ Gallamore West 🙂

I came via pinterest, also. There are only adults living in my house, but I wanted to try it anyway. It was so much fun that my husband can hardly wait to use up the rest of the bar of soap so he can watch it again and again. Some kids never grow up! Thanks for posting. (mine was done in 30 seconds, so be ready to watch from the very beginning)

sounds cool. I am going to try with my grandson. Thanks

Thank you for posting this, I did try it as soon as I read this…. works awesome! When you crumble it it is almost ash-like, so I thought this would be wonderful to use with the ivory laundry detergent recipe instead of grating the soap! Thanks again 🙂

great site, popped over from Pinterest, so glad I found you 🙂

We love “exploding” ivory soap in our house as well. We use our fluffy soap cloud to make bath tub paint. http://www.housingaforest.com/fluffy-bathtub-paint/

Hmmmmm, sounds like I will have to give it a try. I have to wonder why anyone thought up putting soap in the microwave to begin with! LOL http://memoryofron.blogspot.com/2012/01/to-go-or-not-to-go.html

Can’t wait to try w my kindergartner. Think he’ll love it! Thanks!

I make felted soaps… can’t wait to see if this will work – what interesting shapes it would make! 😉

Saw this from Making Memories with Your Kids and wanted to come over here to pin it! Such a great idea – thanks for sharing!

I found you on Pinterest! This experiment was AWESOME. Thanks so much for sharing. Both of my kids were in awe! I am so glad you warned to not put the entire bar in the microwave, because that was my first thought – how cool would it be to make a gigantic one? Yup, I would have had to clean my microwave from being covered in bar soap. Warming up food in a soapy smelling microwave does not sound appetizing at all! Thanks for the heads up!

You have to use a soap that floats – it’s the air bubbles that expand in the micro. that cause this to happen. You can see a video at: http://dsc.discovery.com/videos/time-warp-soap-in-microwave.html They also do this on the Discovery show Head Rush with Kari Byron.

What a great idea! We are so trying this with our kiddos!

Awesome does not even describe this fun experiment! My kids are gonna love this! Thanks 🙂

This is awesome! We are trying this a.s.a.p.

I need to find a British soap that does the same thing!

Found this on Pinterest & I am so glad I looked beyond the pin. This is amazing and I am going to do this with my pre-k classroom. To the employees lounge for some science fun!!! Thank you!

I must be the only one this didn’t for. We followed your instructions exactly and it only puffed up a little. My Ivory soap was a couple of years old. Could this be why?

Just a little FYI: DO NOT try this on a really old bar of Ivory! I tried it & it started to smoke & look like motor oil. I had to take it out before it caught fire. I know the bar was several years old & it didn’t puff up at all. ALWAYS USE A FRESH, NEW BAR!

A co-worker used to do this and mix with oatmeal for a scrub.

i tried this and it didnt work….how come?

Was the soap old? Did you use Ivory Soap???? It needs to be new and MUST be Ivory soap.

My kids are going to LOVE this!! I will also try Tammy’s bathtub “paint”! Thanks!! 🙂

Just tried this and it all turned to powder in no time at all. 🙁 Not sure what happened…the kids are having fun with it nonetheless, but the powder is all over the place, getting up our noses and making us sneeze! lol!

My daughter is going to LOVE this. Thanks for posting. :0)

I just tried it with a NON-IVORY soap. BIG MISTAKE! same result as you, tons of smoke, it melted into a black pool. Guess I’ll hit the store for some IVORY!

Oh no! Sorry guys! Yeah, it HAS to be Ivory soap. When they make Ivory soap air is whipped into it. When it is heated in the microwave, the air expands thus puffing up the soap. Other soaps don’t have air whipped into them.

after you cut the soap i only put one piece or all four?

Only one piece. It grows to be too big to put all four in!

I didn’t read the comments first… and it doesn’t work with Dove Soap! It only melt. For the person asking herself if it was sold in other country…Ivory is sold in Canada too since… forever?! 🙂

Just did this with my kids! They loved it. What a cool thing! Thanks for sharing Courtney

We tried this today. YES with IVORY soap. The bar of soap I had was maybe 6 months old. It caught on fire after about 1 minute and didn’t work and made the house smell awful. Then I got out another bar of IVORY soap from a newer package and dipped it in water just to be sure. It puffed a teeny tiny bit and then smelled up the whole house and was disgusting. I guess the IVORY soap has to fresh from the factory fresh….good grief! I also had a friend go out and buy soap from the store and did it that day. It didn’t puff very much and smelled the house as well.

I have no clue why it didn’t work for you 🙁 Yes, fresh soap does work much better than older soap so the new stuff should have worked. I wonder if your microwave is too strong?

Definitely fresh soap. My six year old nephew and I did this when he came over for the weekend, and my older bar just sat there and sniggered at us. The new though… he was absolutely delighted. We’ve gone through a lot of Ivory soap since then! Thanks for the great and simple idea; it’s priceless

{Kathy} If you don’t think I am doing this today–first by myself just for fun–then letting my kid lets do this you are nuts! We are forever doing silly science around here.

Hysterical!

Too fun! We will definitely be doing this one!!

Fantastic! I am now wondering whether I can get Ivory branded soap in the UK. Hmmm

Ooh, this looks so fun!

when you finish with the soap and it is all blown up and brittle you can grate it down with a grater and mix in one cup of Arm and hammer super washing soda and 1 cup of borax laundry booster and combine really well and use as laundry detergent that is mild. it will not suds up but the ingredients together will do a great job to get your clothes clean!!!

wow…! that’s a cool experience. How do you know this trick..?

That.is……A.W.E.S.O.M.E!! Must try this soon, oh very, very soon!

[…] many cool science projects off hand besides the volcano so I had to get creative. I came across the ivory soap challenge. So we tried it and it was pretty awesome for smaller kids. All you do is take a fresh bar of ivory […]

Please note that this blog is no longer active or updated. I do not check the email associated with this blog and I am not responsible for missing links or downloads.

Return to top of page

Copyright © 2024 · Prose on Genesis Framework · WordPress · Log in

Kids Science Experiment: Ivory Soap Explosion

March 8, 2014 by OneMommy

When I was a little girl I was always fascinated by the fact that Ivory soap could float.  All that air inside, along with the extra moisture found in the little bar of soap, also causes a super fun reaction when you put Ivory soap in the microwave for this simple kids experiment: Ivory Soap Explosion.

If you’ve never done this one before, I guarantee it will get quite a reaction from all the kids, and even the adults!   It’s good clean fun, with no waste.  The soap is still usable once you’re finished!

To begin, we looked at the bar of Ivory soap.  The kids felt it, smelled it, and examined it closely.  I cut a small piece off the corner so they could see how Ivory soap floats.  Then they tried a different type of soap, which, of course, sank right away.

After closely examining the bar we put the soap on a microwave-safe plate and put in in the microwave.

The kids watched in awe as the soap began to grow.

Within a minute the bar of soap had exploded to several times its usual size! We left the Ivory soap in the microwave for 2 minutes. Then we let it cool several minutes before touching it.  (Remember, microwaves make things hot.  Use caution!   Break it in half and checked the insides before letting the kids handle it.)

My kindergartner started crumbling it up right away, anxious to get her hands in the stuff.

The preschooler started off a little more tentatively, but pretty soon the cars joined the mix — it was a blizzard!

They both played with the Ivory soap snow for almost an hour.

Then I got out the cookie cutters.  We mixed a little bit of warm water into the soap until it was able to be molded. The kids used spoons to squish the soap into some cookie cutters.  We left the cookie cutters on a piece of wax paper to dry, and once the soap was dry (overnight), we pushed out our new soap shapes.

As I said, it was good clean fun, and the soap is still usable!

Have your own clean fun with this simple kids science experiment and make an Ivory soap explosion. 

You may also like:

• Simple Soap Carving Craft  
• How to Make Bubble Dough
• Kids Science:  Make a Rubber Egg
• Make an Awesome Soda Pop and Mentos Volcano 

Susie@homemaker-mom says

March 8, 2014 at 5:41 pm

O m y gosh. I do not have little ones but my homeschooled teen would love to try this! Thank you for the awesome post!

OneMommy says

March 12, 2014 at 10:43 am

Oh, it is definitely a winner for any age! My husband thought it was pretty cool himself!

March 8, 2014 at 6:45 pm

Cool! Never heard of this one before!!

Leslie says

March 8, 2014 at 7:27 pm

How cool! I don’t have kids so I don’t get to do cool stuff like this. It looks like the kiddo’s had fun with it.

Valerie says

March 9, 2014 at 9:38 am

I never thought of trying that. We haven’t used bars of soap in years but if I can get my hands on an Ivory bar, I bet the kids would have a blast. Love your ideas for exploring it. Thanks for sharing.

March 12, 2014 at 10:48 am

We don’t tend to use Ivory here…. Not even sure how/why it was in the cabinet! But we had fun playing with it!

March 9, 2014 at 7:30 pm

This looks like so much fun, I will have to pick up some ivory soap tomorrow.

March 12, 2014 at 10:38 am

My preschooler has asked to do it again — definitely a hit! 🙂

Michelle says

March 10, 2014 at 8:08 am

How fun!!! I can’t wait to do this (I’m a big kid at heart :), I’m sure my daughter would love this too 🙂

March 12, 2014 at 10:39 am

LOL — I couldn’t wait to try it myself!

Ashley says

March 10, 2014 at 9:08 pm

Super fun! Thank you for linking up to the Thoughtful Spot Weekly Blog Hop!

Shalynne says

March 11, 2014 at 3:20 pm

I need to remember to do this one! I’ve seen it a couple other places and always forget. Great idea!

March 12, 2014 at 10:41 am

I’d been wanting to try it for a while now — definitely give it a go!

Julie @ Don't Lick Your Sister says

March 11, 2014 at 10:27 pm

This is such a neat idea – had no idea Ivory soap would do this. Thanks for sharing!

March 12, 2014 at 10:40 am

Oh, definitely try it!! I bet Dino would love to use it as snow like my little guy did!

Julie @ Girl on the Move says

March 15, 2014 at 10:09 am

Stopping by from the SITS Share Fest and I absolutely love this idea! Would be a great way to entertain the toddlers!!!

March 16, 2014 at 10:59 pm

Okay this is too cool! I never knew soap would do that! Thank you for stopping by the Thoughtful Spot Weekly Blog Hop this week. We hope to see you drop by our neck of the woods next week!

Donna DM Yates says

March 25, 2014 at 10:19 pm

Wow, I didn’t know about this. I’ll have to try it myself.

[…] you know that when microwaved Ivory Soap makes a foamy explosion? I had NO idea! But you can bet will be trying this experiment soon! Thanks There’s Just One […]

Recent Posts

• Make Learning Easier with DIY Math Manipulatives
• Engineer a Truss Bridge with Craft Sticks
• Dragon STEM Activities
• Fun and Foamy Elephant Toothpaste Experiment
• Shark Party Games — Perfect for Shark Week or a Shark-Themed Birthday Party

Proud Member

Exploding Soap ~ Microwave Science For Kids

The other day I took my kids to a farmers market in town.  Our friends were selling soap that they made from the milk they get from their goats.   They sold little cubes of it with instructions to microwave it for 30 seconds for some “clean fun” with kids.  The little cube of soap grew into this huge cloud of fluffy soap.  My kids loved it, and wanted to do it again and again.

Ivory soap has air bubbles in it so it is said to work best. Cut the soap into smaller pieces, put on a paper towel and microwave on high for 30-45 seconds.  Watch the soap grow and jump out in snake like sections.  You can still use it as soap if you wanted, but it becomes a crumbly mess so once the kids were done playing with it, I tossed it in the trash.

 Or thanks to the tip from one of our readers, you can them chop the soap up  or grate it and use it to make Homemade Laundry Detergent.  Making fun with NO WASTE!

More activities, projects and fun things to do with your kids this summer.

Dirt and Worms ~ Fun summer recipe for kids

 Make your own Crayons ~ Activities to do with kids

Be a Back Yard Detective ~ Activities to do with kids

Wiggle Worm Game ~ Games to do with kids

Make your own Bean Bag Toss ~ Games to do with Kids

Watch a Local Race ~  Frugal Family Activities to do

Corn Starch Gak  Science Project to do with kids

Color Collage  with ads from the paper

DIY Chime Set  ~ Music Fun For Kids

Recipe for  Homemade Slime

 Under the Sea  Art Project for kids

Balloon Barrettes  DIY Kids Fashion

Lady Bugs made out of an egg carton

DIY – Clam Gun

How i spend less than $10 a year on laundry soap, 1 thought on “exploding soap ~ microwave science for kids”.

Maceys face!!! U0001f602U0001f602U0001f602U0001f602

Comments are closed.