Mentos Geyser Experiment- Exploring Different Mints

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My son has been at my heels begging me to do this ONE science experiment. . . The Coke and Mentos Experiment.  

You see, about 3 weeks ago, when he was having too much anxiety to go to school, instead of letting him sit around and play video games, I made him do work.

So he would do math problems, he would read, I would make him learn about historical things.  And then for science, he would watch Science Max on youtube.  

NO JUDGING!  😉 It’s not like I had a science curriculum laying around my house that I could use!

Youtube doesn’t have to be your enemy if you know how to use it.  And let me tell you, if you haven’t let your kids watch Science Max, then they are missing out.  

He is a REAL person, no cartoons.  He does all kinds of science experiments, and he makes them all big, huge, and “don’t try this at home” kinds of experiments!

My son saw one where he put mentos into a coke bottle and the bottle foamed out all over the place like a fizzy soda fountain.  

So, of course, he wanted to try it. 

Why did it take us so long?  Well, we don’t drink soda and we don’t eat mentos.  So it meant an extra trip to the store.

Eventually, we got about 5 extra minutes one day and jumped in the car to go to the grocery.  We specifically went for coke and mentos, nothing else. 

So naturally, we wound up buying gum, a bag of Doritos, and some candy for our candy bin that I had just cleaned out.  All that on top of the coke and mentos we needed for the experiment.

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How did we come up with a new and improved experiment?

We made it as far as the checkout line before I said, “you know, we already know what is going to happen.”  My son said, yeah.

So I started thinking. Prior to us walking up to the checkout counter, he had been asking me why the coke foams out when the mentos go in. I, of course, didn’t know and neither did he. 

But one thing we both could agree on …that we both had different ideas of how it worked.

I thought it was the sugar that caused the reaction and my son thought it was the mint.  

So we headed back to the mint and candy aisle to create a NEW experiment with coke and mint candies.

Our new question was going to be, “Does the coke fountain only happen with Mentos? 

What you need for a New and Improved Coke and Mentos Experiment

We bought 8 – 12 oz bottles of coke instead of just one.  Then we bought some other kinds of mints. To be specific, we bought LifeSaver Pep-O-Mints, Altoids peppermint, and Ice Breakers peppermint to go along with the peppermint Mentos we already had.

When we got home we set up our experiment outside.  

5 bottles of coke – one for each type of mint- and one control (which would have no mint).

Before we dropped the mints into the coke bottles, we tasted each mint and decided if it tasted more sugary or mintier.

I know that none of this is very “scientific”. But the idea in 3rd grade is not to get your child to follow the steps to a “T” and make a huge discovery.

It is just to get them to learn how to think. It is a growth mindset that helps them answer quetions they have in a fun way.

We labeled all the coke bottles so we would know which mints went into which bottle. Then we make our predictions about which mints we believed would cause the biggest reaction. And last, I let the kids drop the mints in.  

Check out the video! (and try not to be bothered by the “home video” mom narration or the fact that my dog is hanging out in the middle of our experiment!

What we should have done differently…

There were a few things that we could have done differently that would have made the experiment better.

  • We could have used one or two mints per bottle instead of 12…not sure how we even came up with that number.
  • We could have kept our dog inside so she didn’t want to drink the coke off the ground and eat the mints.  
  • We could have used Diet Coke. Supposedly, Diet Coke is the soda that works best with Mentos.
  • We could have used two-liter bottles of coke instead of 12 -oz bottles of coke.

Why you should do fun Science with your kids

The purpose of this post was not to get you to start doing science experiments.  Although they are a lot of fun!

No, the purpose was to get you to realize that you can use experiments that you already know and expand on them to answer the questions that arise in your kids about how things work and why.

How the Coke and Mentos Experiment Works

In a traditional Coke and Mentos experiment, the reaction is said to occur due to something called nucleation. I am not going to get into the details about it, but essentially, the more places that an object has that the CO2 can hold onto, the better the geyser will be. But this does not coincide with what my son and I were testing.

In this experiment, we realized that the mintiest of the mints, the Altoids, didn’t cause a very big reaction.  However, we felt like the reaction from LifeSavers was the best and longest.

So I would love to find out what the nucleation factor is for the LifeSaver mints. I am guessing that more sugar means the object has more nucleation sites for the CO2 to attach to and that is why the fountain was higher for this mint than Mintos.

Overall,  we decided it was probably the sugar that caused the larger reactions, not the mint.

But since we are 3rd-grade scientists, I am more interested in the fun of the experiment and getting him to think.

Can You Eat Mentos and Drink Coke At the Same Time?

Despite the fact that adding mentos to Coke or Diet Coke causes an exploding fountain of foam, this does not happen in the human body. So rest assured, that you will not start shooting foam out of your mouth if you eat Mentos and drink Coke!

I challenge you to engage your children with this experiment… or a different one! And just HAVE FUN listing to all the questions they come up with to explore further!!

How Do You Do The Mentos Experiment?

Coke And Mints Geyser Experiment

An expanded version of the traditional Diet Coke and Mentos Geyser Experiment.


  • 5 -12 ounce Coke
  • 2 candies mentos
  • 2 candies LifeSaver Mints
  • 2 candies Altoids
  • 2 candies Ice Breakers
  • 5 post-its


  1. Gather up your materials.
  2. Label each bottle of Coke using the post-it notes as follows: Bottle 1: LifeSaversBottle 2: AltoidsBottle 3: MentosBottle 4: IcebreakersBottle 5: Nothing
  3. Have your child drop the two candies into each bottle. It is more fun to do them one bottle at a time so you can watch each reaction.
  4. Ask them what they think happened and if they have other questions they could explore with a similar experiment.