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Mentos and Coke Experiment – How to Do It! [Full Guide]

Have you ever taken a can of soda, shook it up, and given it to your friend?

What happens?

Well, it’s probably not pretty. And you may not have a friend for a day or two until they forgive you.

But making soda explode is fun. And there is a way to make it really go boom if you have a few pennies and a bit of time on your hands.

Note – be sure to only try this experiment with a responsible adult!

It really only takes a few minutes to setup the mentos and coke volcano experiment. And it’s a great way to learn about chemical reactions.

It’s also a lot less work than your classic paper mache volcano. So, if you want some quick and easy fun, get some paper towels because we’re about to make a sweet mess.

What Will I Need For The Mentos And Coke Volcano?

There really aren’t that many supplies you need to make a mentos and coke volcano.

But here’s the list:

An outdoor area with no ceiling or roof

One roll of Mentos candies

A two-liter bottle of diet soda (diet soda makes for a much better reaction, but you can use regular soda if you like. It just won’t be nearly as awesome.)

A tube the width of the Mentos . It needs to be wide enough to use as loader for the Mentos

An index card (picture below)

The Mentos And Coke Volcano Experiment

Now it’s time to actually run the experiment, but first, we need to make a hypothesis.

The Hypothesis

The scientific method is an important way scientists make observations and come to conclusions.

Part of the scientific method is making a prediction called a hypothesis .

Write down what you think will happen when placing the Mentos in the soda bottles.

Do a little bit of research about the ingredients of Mentos and soda.

This will help you make an informed guess as to what will happen.

Now You Test The Hypothesis

In an experiment, you have two groups: an experimental group, and a control group.

Open the soda bottle, set it down and write down what you observe about it.

This will count as your control group. It’s what happens when you put nothing in the soda.

Now take the Mentos in your tube loader.

Put the index card on top of the tube loader and turn the tube upside down.

The candy should not fall out.

Be ready. The reaction happens fast, so don’t have your face over the bottle.

Place the index card and candies over the mouth of the bottle. Make sure the candies are in line with the mouth of the bottle.

You want the candies going in the bottle and not falling over the side.

Now remove the index card and let candies fall in and step away from the Mentos and coke volcano.

Write down what happened when you dropped the Mentos in the coke.

Did what you hypothesize happen? Compare your notes on the experiment to the control group.

Let us know what you observed in your science experiment!

FREQUENTLY ASKED QUESTION

1. can i use any type of mentos candy for the experiment.

Yes, you can use any type of Mentos candy for the experiment. The most commonly used Mentos candies are the original mint-flavored ones, but you can also use fruit-flavored or other varieties. The key factor is the rough surface of the Mentos candy, which helps to create nucleation sites for the carbon dioxide bubbles in the Coke. This happens because Coke contains dissolved carbon dioxide gas.

2. What happens if I use diet Coke instead of regular Coke?

If you use cold diet Coke instead of regular Coke in the Mentos experiment, you can still expect an explosive reaction. However, the reaction may not be as vigorous as with regular Coke. Diet Coke contains artificial sweeteners like aspartame, which may slightly affect the reaction. Nonetheless, the combination of Mentos and diet Coke can still produce a notable geyser, so it’s worth giving it a try. SO it will be the mentos geyser experiment.

3. Is the Mentos and Coke experiment suitable for children to try at home?

The Coke and Mentos experiment can be a fun and engaging activity for children to try at home. However, ensuring proper adult supervision and following safety precautions is important. Conducting the mentos experiment outdoors or in a well-ventilated area is recommended to avoid any potential mess or accidental spills. Additionally, remind children not to consume the Coke or Mentos mixture, as it is unsafe for ingestion. By taking these precautions, the Coke and Mentos experiment can provide children an educational and entertaining experience.

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How to Make a Soda Bottle Volcano

Last Updated: July 18, 2024 Fact Checked

This article was co-authored by Bess Ruff, MA . Bess Ruff is a Geography PhD student at Florida State University. She received her MA in Environmental Science and Management from the University of California, Santa Barbara in 2016. She has conducted survey work for marine spatial planning projects in the Caribbean and provided research support as a graduate fellow for the Sustainable Fisheries Group. This article has been fact-checked, ensuring the accuracy of any cited facts and confirming the authority of its sources. This article has been viewed 982,951 times.

Making a soda-bottle volcano is a classic science experiment that doubles as a great excuse to make an explosive mess. There are multiple combinations of materials that will lead to a fun explosion. Two of the classic soda-bottle volcanos are made with soda and Mentos candy mints(which can produce eruptions of up to 18 feet if done correctly) or a combination of baking soda and vinegar. Gathering a few household items can lead to a fun afternoon of volcanic explosions in the backyard.

Designing the Volcano

• If you’re working with scrap material, consider decorating the base to look like a flat landscape. You may want to paint it, cover it with moss, apply green felt to indicate grass, attach miniature trees, etc.

• A caramel-colored soda will probably look the most like lava when your volcano erupts, so avoid clear drinks. Both diet and regular soda work for this experiment, but diet soda erupts higher.
• If gluing the bottle, let the bottle reach room temperature. A cold, sweating soda bottle will never glue properly. Avoid using hot glue, which might melt the bottle and make a mess.
• If you’re doing a vinegar and baking soda volcano, you will attach an empty bottle to the board.

• Avoid covering the cap of the bottle or you won’t be able to activate the volcano. Ensure you have access to the opening so you can add Mentos or baking soda for the eruption!

• You may even want to press pebbles, dirt, and moss into the surface to give it a more natural appearance.

Using the Soda and Mentos Method

• This experiment is best done outside, but if you must be inside, lay down a large plastic tarp first.

• Warn any spectators to stand back.

• Method 1: Make a paper tube with the same width as the bottle neck. It should be long enough to fit the number of Mentos you want to put inside. Place an index card over the bottle mouth, place the tube over the hole, and fill it with Mentos. When you are ready to erupt, you will slide the card out, releasing the Mentos into the bottle. [4] X Research source
• Method 2: Loosely scotch tape the entire roll of Mentos together. When it’s time, you will drop the taped chain directly into the open bottle.
• Method 3: Insert into the bottle a funnel with a mouth that is wide enough to allow the Mentos to pass, but small enough to fit inside the neck of the bottle. You will drop the Mentos through the funnel and remove the funnel once the Mentos are in the bottle.

• If using the paper tube method, remove the card holding the Mentos in place and let them all slide into the bottle at one time.
• If using the tape method, simply drop the piece of taped-together Mentos into the mouth of the bottle.
• If using the funnel, drop all the Mentos into the funnel at the same time. Remove the funnel once they’re all in and run back.

Using the Baking Soda and Vinegar Method

• Do a little experimentation to find the proper amounts of each material to get the size of eruption you want.
• Use red-wine vinegar for the best lava coloring. Alternatively, you can also add red or orange food coloring to white vinegar.
• You can use a smaller plastic bottle, but will have to adjust the ingredients accordingly.

• If the weather is agreeable, place the volcano outside.

Community Q&A

• If you drink soda and then eat Mentos, do not worry at all; the acid in your mouth and stomach will stop it from reacting with the soda in your belly. Thanks Helpful 0 Not Helpful 0
• Don't use a 3- or 1-liter bottle, as the neck-to volume-ratio is too large. A 3-liter bottle results in about a 6-inch tall fountain and a 1-liter bottle it will just foam over the top. Thanks Helpful 0 Not Helpful 0
• Stay away from the immediate area after starting the volcano. It will get messy. Thanks Helpful 0 Not Helpful 0

Things You'll Need

Volcano and Base

• Scrap wood or cutting board for a base
• Play dough or clay
• Chicken wire
• Strips of paper
• White craft glue
• Acrylic paint

Soda and Mentos Method

• 2-liter bottle of soda (diet is preferable)
• Roll or box of Mentos (mint works best)
• A funnel, one index card, or scotch tape

Baking Soda and Vinegar Method

• Empty 2-liter bottle
• Baking soda
• Red-wine vinegar
• Food coloring

You Might Also Like

• ↑ https://www.jpl.nasa.gov/edu/learn/project/make-a-volcano/
• ↑ https://www.weatherwizkids.com/experiments-volcano-soda-bottle.htm
• ↑ https://www.sciencefun.org/kidszone/experiments/how-to-make-a-volcano/
• ↑ https://www.nhm.ac.uk/discover/how-to-make-a-volcano.html

About This Article

To make a soda bottle volcano, first combine 2 parts vinegar, 1 part water, and a squirt of dishwashing liquid. Then, put the mixture in an empty 2-liter soda bottle and add a spoonful of baking soda, which will react with the vinegar to make your volcano erupt. Alternately, you can drop Mentos candies into a 2-liter bottle of cola. You can then watch the eruption, which happens when the candies react with the carbon dioxide in the soda to push the liquid out of the bottle. Just be sure to move away quickly, since the eruption can make quite a mess! To learn from our Scientist reviewer how to get all the Mentos into your soda bottle at the same time, read on! Did this summary help you? Yes No

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How to Make a Mentos & Diet Soda Chemical Volcano Eruption

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Chemical volcanoes are classic projects for science fairs and chemistry demonstrations. The ​ Mentos and diet soda volcano is similar to the baking soda volcano , except the eruption is really powerful, capable of producing jets of soda several feet high. It's messy, so you might want to do this project outdoors or in a bathroom. It's also non-toxic, so kids can do this project. This simple  chemical volcano takes a few minutes to set up and erupts for a few seconds

What You Need

• Roll of Mentos candies
• 2-liter bottle of diet soda
• Test tube or sheet of paper
• A mop for cleanup

Making the Mentos and Soda Erupt

• First, gather your supplies. You can substitute another candy for the Mentos, such as M&Ms or Skittles, but ideally, you want candies that stack into a neat column with minimal space between them, have a chalky consistency, and barely fit through the mouth of a 2-liter bottle.
• Similarly, you could substitute normal soda for diet soda. The project will work just as well, but the resulting eruption will be sticky. Whatever you use, the beverage has to be carbonated!
• First, you need to stack the candies. The easiest way to do this is to stack them in a test tube narrow enough to form a single column. Otherwise, you can roll a sheet of paper into a tube just barely wide enough for a stack of candies.
• Place an index card over the opening of the test tube or end of the paper tube to hold the candies in the container. Invert the test tube.
• Open your full 2-liter bottle of diet soda. The eruption happens very quickly, so set things up: you want the open bottle/index card/roll of candies so that as soon as you remove the index card, the candies will drop smoothly into the bottle.
• When you're ready, do it! You can repeat the eruption with the same bottle and another stack of candies. Have fun!

How the Mentos and Diet Soda Experiment Works

The Diet Coke and Mentos geyser is the result of a physical process rather than a chemical reaction. There's a lot of carbon dioxide dissolves in the soda, which gives it its fizz. When you drop a Mentos into the soda, tiny bumps on the candy surface give the carbon dioxide molecules a nucleation site or place to stick. As more and more carbon dioxide molecules accumulate, bubbles form. Mentos candies are heavy enough they sink, so they interact with carbon dioxide all the way to the bottom of the container. The bubbles expand as they rise. The partially dissolved candy is sticky enough to trap the gas, forming a foam. Because there's so much pressure, it all happens very quickly. The narrow opening of a soda bottle funnels the foam to make a geyser.

If you use a nozzle that makes the opening at the top of the bottle even smaller, the jet of liquid will go even higher. You can also experiment using regular Coke (as opposed to the diet versions) or tonic water (which glows blue under a black light).

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Diet Coke and Mentos Soda Geyser

The Diet Coke and Mentos soda geyser, also known as the soda and candy fountain or volcano, is a physical reaction between candy and carbon dioxide that instantaneously releases the gas so it shoots into the air. There is a lot of science behind this deceptively simple project! Here are instructions for performing the original project, tips for getting the tallest eruption, options for material substitutions, and a look at how the Diet Coke and Mentos geyser works.

All you need is a packet of Mentos candies and a 2-liter bottle of Diet Coke:

• Roll of Mentos candies
• 2-liter bottle of Diet Coke

Make sure the candy is fresh and the bottle of soda is unopened. Freshness matters!

You also need a way of delivering the candies into the soda. One method is just dropping the column from your hand, but rolling them into a paper or index card tube is more reliable. Stacking them into a test tube is another option.

Substitutions

While Mentos and Diet Coke work best, you have other options:

• Any carbonated beverage
• Any candy that stacks neatly into a column
• Coins, shot, or other small items that fit through the bottle opening
• Sand or salt instead of candy (which work quite well)

In general, diet carbonated beverages produce higher fountains than sugary ones. Also, they don’t produce a sticky mess. Uncarbonated beverages, like juice or water, do not work at all. Objects with smooth, flat surfaces (like coins) do not work nearly as well as other options.

How to Make the Diet Coke and Mentos Soda Geyser Erupt

The project is messy. You might want to step outdoors.

• Open the Mentos candies and stack them into a single column.
• Open the bottle of soda.
• Drop the column of candy into the bottle, all at once.

If you have more candy, you can repeat the eruption using the same bottle of soda. It won’t be quite as dramatic, but still works.

Tips for Getting the Biggest Eruption

• Diet Coke or other diet colas outperform any other drinks. There are a lot of potential reasons for this, mainly involving the effects of aspartame, potassium benzoate, and other ingredients on the surface tension and foaming capacity of the beverage. The worst carbonated beverages for this project are carbonated water and sparkling alcoholic drinks.
• The blue Mentos candies work better than other flavors. The fruity Mentos are reportedly the worst flavor. Freshly unwrapped candies are best. Old candy is not very effective, probably because humidity changes the candy surface.
• A 2-liter plastic bottle works better than any smaller bottle, whether it is plastic or glass.
• You get a better eruption at high altitude or low atmospheric pressure compared with sea level or other high pressure situation.
• Warm soda produces a higher fountain than cold soda.

How the Diet Coke and Mentos Experiment Works

The Diet Coke and Mentos eruption is a physical process more than a chemical reaction. The candy surface has many tiny imperfections and cavities, each only a micron or so in size. When you drop the Mentos into the soda there are numerous minute air bubbles stuck onto them. These little bubbles act as nucleation sites for rapid de-gassing of the soda:

CO 2 (aq) → CO 2 (g)

Because the nucleation sites lower the activation energy for bubble formation, you can say they catalyze the reaction.

The candies are dense enough that they sink to the bottom of the soda bottle, interacting with dissolved carbon dioxide as they fall. As carbon dioxide bubbles form, the gas is lighter than the liquid and the bubbles rise. As they rise, they expand. The pressure of the gas results in a quick release of pressure, making a geyser out of the soda. Ingredients in the partially-dissolved candy help the bubbles keep their shape and form a foam as the liquid ejects from the bottle.

Numerous investigations into why diet soda (especially cola) works better than sweetened soda or why Mentos works better than other candies answer some questions, but not all of them. The ingredients in the soda make a difference. However, which ones enhance bubble formation and which suppress it are unclear. The chemical composition of the candies likely contributes to bubble formation, but it’s really their surface structure that matters the most.

Turn the Science Project Into an Experiment

Performing the Diet Coke and Mentos project is easy, but turning the project into an experiment is also simple. Just find a variable under your control, predict the outcome from changing it, conduct an experiment that tests this hypothesis , and then analyze your results and see if your prediction was correct. Here are some ideas of variables you can explore:

• Is there an optimal number of candies for the best eruption?
• Compare different types of carbonated beverages. Do you think, for example, that Coke Zero performs as well as Diet Coke? Do other brands of diet cola perform as well?
• Explore the effect of soda temperature on fountain formation. If you see a difference, comparing chilled and warm soda, can you explain it ?
• Are there any candies that work as well as Mentos? In general, is there a way of predicting whether or not a particular kind of candy produces an eruption?
• What effect do you expect, if you add a bit of bubble solution or dishwashing liquid to the soda before adding the candy?
• Design different “candy delivery” systems. What are the pros and cons of each of them?
• Can you make a nozzle that reduces the diameter of the bottle? If so, what effect does this have on the height of the eruption?

Fun Facts About the Diet Coke and Mentos Project

• The original soda and candy fountain project, circa 1910, used Wint-O-Green Lifesaver candies (which as also great for the “spark in the dark” triboluminescence project ). However, the company changed the candy diameter in the 1990s and it no longer fits into most bottles.
• Scientists estimate the eruption releases between 2.4 and 14 million bubbles per liter of Diet Coke. Regular Coke produces a lot less bubbles.
• A single Mentos candy contains 50,000 to 300,000 nucleation sites, although the reaction does not utilize every one of them.
• Coffey, Tonya Shea (2008). “Diet Coke and Mentos: What is really behind this physical reaction?”. American Journal of Physics . 76 (6): 551–557. doi: 10.1119/1.2888546
• Kuntzleman, Thomas S.; Imhoff, Amanda M. (2021). “How Many Bubbles Are in the Foam Produced during the Candy-Cola Soda Geyser?”. Journal of Chemical Education . 98 (12): 3915–3920. doi: 10.1021/acs.jchemed.1c01001
• Kuntzleman, Thomas S.; Annis, Jezrielle; Anderson, Hazel; Kenney, Joshua B.; Doctor, Ninad (2020). “Kinetic Modeling of and Effect of Candy Additives on the Candy–Cola Soda Geyser: Experiments for Elementary School Science through Physical Chemistry”. Journal of Chemical Education . 97 (1): 283–288. doi: 10.1021/acs.jchemed.9b00796
• Kuntzleman, Thomas S.; Johnson, Ryan (2020). “Probing the Mechanism of Bubble Nucleation in and the Effect of Atmospheric Pressure on the Candy–Cola Soda Geyser”. Journal of Chemical Education . 97 (4): 980–985. doi: 10.1021/acs.jchemed.9b01177

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Erupting Mentos and Coke Experiment

Love fizzing and exploding experiments? YES!! Well, here’s another one the kids are sure to love! All you need are Mentos and Coke. Put the scientific method into practice with two easy-to-set-up Mentos science experiments. Record your results with a video camera so you can enjoy seeing the exploding fun up close (and over and over again)! Learn all about the Mentos and Coke reaction!

Grab Some Mentos and Coke

Our Mentos and soda experiment is a fun example of a physical reaction. Read on to learn more about how this Mentos and Coke reaction works.

We love fizzing experiments and have been exploring science for kindergarten, preschool, and early elementary for over 8 years now. Make sure to check out our collection of simple science experiments for kids.

Our science experiments are designed with you, the parent or teacher, in mind! Easy to set up, and quick to do, most activities will take only 15 to 30 minutes to complete and are heaps of fun! Plus, our supplies lists usually contain only free or cheap materials you can source from home!

Grab a packet of Mentos and some Coke as well as assorted soda flavors, and find out what happens when you mix them together! Do this activity outside to make clean-up a breeze. Make sure to put it on a level surface so the cups don’t tip over.

ALSO CHECK OUT: Pop Rocks and Soda

NOTE: This experiment is a less-mess version and more hands-on for younger kids. See our Mentos Geyser version for a bigger eruption!

Coke and Mentos Reaction

You might be surprised to know that the Mentos and Coke reaction is an example of a physical change ! It’s not a chemical reaction like how baking soda reacts with vinegar and a new substance, forming carbon dioxide. So how does it work?

Inside the Coke or soda, there is dissolved carbon dioxide gas, making the soda taste fizzy when you drink it. Usually, you can find these gas bubbles coming out of the soda on the sides of the bottle, which is why it becomes flat after a while.

Adding Mentos speeds up this process because more bubbles form on the Mentos’s surface than on the bottle’s side, pushing the liquid up. This is an example of a change of state of matter . The carbon dioxide dissolved in the Coke moves to a gaseous state.

In the first experiment, if the size of the Mentos is the same, you will notice no difference in the amount of foam produced. However, when you make the pieces of Mentos smaller it will cause more bubbles to form and speed up the physical reaction. Give it a go!

In the second experiment, when you test out Mentos with different sodas, the soda that produces the most foam will likely have the most dissolved carbon dioxide or be the fizziest. Let’s find out!

Mentos and Coke Experiment #1

Do Coke and Mentos work with fruit Mentos? You can do this experiment with any Mentos! This first experiment uses the same soda to test which variety of candy creates the most foam. Learn more about independent and dependent variables.

TIP: Mentos and coke at room temperature generally produce the best results.

• 1 sleeve Mentos Chewy Mint candy
• 1 sleeve Mentos Fruity candy
• 2 (16.9 to 20 ounce) bottles of soda (diet sodas tend to work the best.)
• Video camera or smartphone with video (for replay)

HOW TO SET UP MENTOS AND SODA EXPERIMENT #1

STEP 1. To analyze the results, set up a video camera or smartphone with video capabilities to capture the experiment.

STEP 2. Prepare the candy by removing the different types from their sleeve and placing in separate cups.

STEP 3. Pour equal amounts of the same soda into two other cups.

STEP 4. Make sure the camera is recording, and drop the candy into the soda simultaneously. One variety of candy goes into one cup of soda, and the other variety goes into the other cup of soda.

STEP 5. Analyze to see which variety of Mentos creates the most foam. Was there any difference? 

Mentos and Coke Experiment #2

What type of Coke reacts best with Mentos? In this second experiment, use the same variety of Mentos and instead test to find out which kind of soda creates the most foam.

• 3 sleeves Mentos Chewy Mint candy OR Mentos Fruity candy
• 3 (16.9 to 20 ounce) soda bottles in different varieties (diet sodas tend to work the best.)

HOW TO SET UP COKE AND MENTOS EXPERIMENT

STEP 2.  Choose one variety of Mentos candy to use for the experiment. Prepare the candy by removing it from the sleeve and placing one sleeve of candy into each cup.

STEP 3. Pour equal amounts of the different sodas into cups.

STEP 4. Simultaneously, drop the candy into the soda.

STEP 5. Look at the video and analyze which variety of soda creates the most foam.

Expand the Mentos and Coke Experiments

• Test cups, bottles, and vases of different shapes (wide at the bottom but narrow at the top, cylindrical, or directly in the soda bottles) to test whether the width of the cup makes a difference in how high the foam will shoot.
• Design unique ways for dropping the candy into the soda. For instance, create a tube that fits around the mouth of the soda bottle. Cut a slit into the tub that runs ¾ across the width of the tube. Slide an index card into the cut slit. Pour the candy into the tube. Remove the index card when you are ready to release the candy into the soda.
• Add different ingredients to the soda to test whether the amount of foam changes. For instance, we have tested adding food coloring, dish soap, and/or vinegar to the soda while adding baking soda to the cup with the candy.

TIP: Want to try the more traditional Mentos and Coke Rocket, see it here!

Turn It Into A Mentos and Coke Science Fair Project

Science projects are an excellent tool for older kiddos to show what they know about science! Plus, they can be used in various environments, including classrooms, homeschool, and groups.

Kids can take everything they have learned about using the scientific method , stating a hypothesis, choosing variables , and analyzing and presenting data.

Want to turn this Coke and Mentos experiment into a cool science project? Check out these helpful resources below.

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Spurting Science: Erupting Diet Coke with Mentos

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Key concepts Chemistry Physics Materials science Carbonation Physical reactions Explosions Introduction Have you ever seen the Diet Coke and Mentos experiment that is all over the Internet and wondered what makes the reaction work? You might think that there is some ingredient in a Mentos candy that causes a chemical reaction with the soda pop, like the way baking soda reacts with vinegar. But the amazing eruption that takes place when Mentos are dropped into Diet Coke or other brands of diet soda pop is not a chemical reaction at all! Instead it is a physical reaction. That means that all of the pieces of the reaction are there, but that they are simply rearranged. It also means changing some factors may cause a larger or smaller physical reaction to take place. Background A carbonated beverage is packed full of dissolved carbon dioxide gas, which forms bonds with water. While the soda is in the bottle, the gas is kept in solution by the bottle's pressurized conditions. When you pour some soda into a glass, some gas escapes and forms foam, but most stays trapped by the surface tension of the water. But all those gas bubbles want to escape, making it no wonder that soda makes you burp! To create bubbles, the carbon dioxide needs to interact with itself, which means that the carbon dioxide's bonds with water in the Diet Coke must be broken. A Mentos candy can help with this. Although the candy may look smooth, if you looked at it under a microscope you'd see tiny bumps coating its entire surface. This rough surface allows the bonds between the carbon dioxide gas and the water to more easily break, helping to create carbon dioxide bubbles and cause the classic eruption. The speed at which the Mentos falls through the soda can affect how large the eruption is, and this can be tested by comparing whole with crushed Mentos, the latter of which are less dense. Materials •    Wax paper •    Cutting board •    Knife •    One roll of Mentos (at least eight candies) •    Two index cards •    Tape •    Two two-liter bottles of Diet Coke •    An outdoor area at least two meters from buildings •    Eye protection (safety goggles or glasses) •    Video camera with either a tripod or a helper to take the images (optional) Preparation •    Place a piece of wax paper on top of the cutting board. On the wax paper, carefully use a knife to crush and cut four Mentos candies into many small pieces. An adult may help you cut up the candies. What does the inside of the candies look like? •    Make a Mentos cartridge to hold the candies for you before you drop them into the Diet Coke bottle by rolling an index card into a tube, slightly larger than the diameter of a Mentos candy. Tape the tube together on the side. •    Be sure to wear eye protection when putting the candies into the cola! •    Wear clothes that you would not mind if they get splashed with a little soda pop—this activity can get a little messy! Procedure •    Place a Diet Coke bottle in an outdoor area, at least two meters from any buildings or anything hanging above the area, such as eaves, overhangs or wires. Make sure that the bottle is on a level surface and stably standing straight. Why do you think all of this is important? •    If you want to videotape the reactions, set up the video camera so that it has in its viewfinder the bottle and a height equivalent to at least the first story of a building. •    Carefully remove the cap from the bottle and place the flat index card on top, covering the hole. •    Add four whole Mentos candies to your cartridge, put on your eye protection, and start the video camera. •    Place your full cartridge on top of the flat index card. Line up where the opening of the bottle is with the opening of your cartridge. Quickly pull out the flat index card, releasing the Mentos candies into the bottle. Then step back without tipping the bottle over or disturbing the reaction. •    How quickly did the reaction start to happen, and how quickly did it stop? About how high did the eruption go? How much cola is left in the bottle? •    When the bottle stops spouting, stop recording. •    Remove the spent cola bottle and place a new full bottle in the same position, again making sure that it is level and stably standing straight. As with the first bottle, remove the cap and place the flat index card on top, covering the hole. •    Add your four crushed Mentos candies to your cartridge, pouring them in from the wax paper. Put on your eye protection and start the video camera. •    Like you did before, place your full cartridge on top of the flat index card, then line up where the opening of the bottle is with the opening of your cartridge. Quickly pull out the flat index card, releasing the crushed Mentos into the bottle, then step back without tipping the bottle over or disturbing the reaction. •    How quickly did the reaction start to happen, and how quickly did it stop? How high did the eruption appear to go? How much liquid is left in the bottle? Is it more or less than the amount that was left when you used whole candies? •    When the bottle stops spouting, stop recording. If you videotaped the reactions, you can watch your videos now. What do you notice from the videos? •    Which reaction went higher, the whole or the crushed Mentos? •    Extra : Find an exterior wall of a building with no windows and set a Diet Coke bottle at the base of the wall. Use a tape measure and blue painter's tape to mark off the height from the top of the bottle in meters. Then repeat this activity three times, with the bottle in front of the tape-marked wall, video taping it each time. When you review the recordings, use slow motion and pause the recording when the spout is at its maximum height. Using the tape marks in the background, estimate the height of the spout. Calculate the average height of the fountains for the whole and for the crushed Mentos . What is the difference in height of the eruptions? •    Extra: What other factors affect the size of the Mentos and Diet Coke eruption? You can try testing different kinds of carbonated beverages, different kinds of candies with different shapes and textures or using other things to start the reaction, like rock salt, pennies or dice. Which beverages, candies or other things cause the largest and smallest fountains? Why do you think this is? •    Extra: Do this activity again but instead of testing whole Mentos versus crushed, compare warm versus cold Diet Coke. Does temperature affect the eruption height? Observations and results Was the eruption higher when whole Mentos candies were used compared with crushed candies? Was less Diet Coke left in the bottle after the reaction with the whole candies compared with the crushed ones? In the Diet Coke bottle the Mentos candy provides a rough surface that allows the bonds between the carbon dioxide gas and water to break more easily, helping to create carbon dioxide bubbles. As the Mentos candy sinks in the bottle, the candy causes the production of more and more carbon dioxide bubbles, and the rising bubbles react with carbon dioxide that is still dissolved in the soda to cause more carbon dioxide to be freed and create even more bubbles, resulting in the eruption. Because Mentos candies are rather dense, they sink rapidly through the liquid, causing a fast, large eruption. The crushed Mentos candies, however, are not as dense as the whole ones, which causes them to sink more slowly, creating a relatively small cola fountain, which should also leave more liquid in the bottle than the larger eruption with whole Mentos candies did. Cleanup Hose off any part of a building that was splashed with Diet Coke. If you try this project with regular Coke, the eruption should still happen but its sugary content may make cleaning more difficult. More to explore Physicists Explain Mentos–Soda Spray from Scientific American Science of Mentos–Diet Coke explosions explained from New Scientist The Science of Coke and Mentos from EepyBird.com Why do Mentos mints foam when you drop them into soda pop? from General Chemistry Online Coke® & Mentos®—Nucleation Goes Nuclear! from Science Buddies

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Mentos and Coke Volcano

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You have probably seen or heard about this classic experiment before that involves dropping mentos into a bottle of coke and watching the soda erupt everywhere! This time we are going to add a little extra to this thrilling experiment with a homemade geyser tube. So let’s get started making this Mentos and Coke Volcano

Find more fun Plastic Bottle Experiments here!

This has always been one of my favorite experiments to do! It is always fun to watch the reaction between the Mentos candy and the carbonated soda create a dazzling, bubbly, and sticky fountain into the sky…which is also why I highly recommend doing this science experiment outside!

Table of Contents

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Supplies Needed:

• 2 Liter Bottle of Coke (or any kind of carbonated soda)
• Duct t a pe or electrical tape
• A toothpick
• 1 roll of Mentos (fruit or mint-flavored)
• Construction paper or card stock
• Safety glasses
• Scissors (optional)

How to make the soda and mentos experiment go higher with a geyser tube

• Roll a tube of Mentos up in construction paper or card stock. Tape the ends and middle to hold it in place and slide the Mentos tube out.
• Insert your new geyser tube carefully into the top of your soda bottle and secure it to the bottle with duct tape.
• Poke a toothpick into the lower part of the geyser tube just above the opening of the bottle.
• Place your soon to be coke and mentos volcano in a place that you are okay with getting sticky and messy (this is the part I prefer to do outside).
• Make sure your toothpick is all the way through the center of the geyser tube to keep the Mentos from falling and put on safety goggles.
• Gently and slowly drop about 5 Mentos into the top of your geyser tube.
• Pull the toothpick out of the paper tube to release the Mentos into the bottle and quickly get out of the way to enjoy watching the eruption!

Step 1: Create your geyser tube

Before we get started doing the most exciting eruption part of this experiment, we need to make the geyser tube. I promise taking the extra time to make this will be well worth it and make the Coke and Mentos volcano go higher!

To make this geyser tube you will need to grab a piece of construction paper or card stock. The roll of Mentos is the perfect sized diameter to roll your paper around to make a geyser tube. Begin rolling your paper longways with the roll of Mentos inside to help shape your paper into the tube that you need.

Once you have rolled the paper up as tightly as you can around the Mentos, grab some electrical tape or duct tape and wrap both ends of the geyser tube to secure it in place. You might also want to put a piece of tape over the seam of the paper in the middle of the tube to make sure it doesn’t unroll.

When you are done taping the middle and ends of the tube and it feels nice and secure, go ahead and tip the tube up and slide the roll of mentos out of the tube.

Step 2: Connect your geyser tube to the top of the soda bottle

Now that you have created your magical geyser tube, go ahead and attach it to the opening at the top of the 2-liter bottle of soda. Before doing this remember to take the cap off the bottle.

Depending on how tightly your geyser tube was rolled up, you should be able to insert the end of the tube into the inside opening of the bottle. If your geyser tube was rolled a little bit loosely and has a digger diameter, then you can slide it over the outside of the opening of the bottle instead.

Once you have either inserted the tube on the inside of the opening of the bottle or slid the tube over the opening, go ahead and securely attach the tube to the bottle with electrical tape or duct tape. I personally prefer to use duct tape since it seems to stick better and stay on better when it gets wet in the eruption.

You do want to wrap a couple of layers of tape tightly around the connection to get the best seal possible. The better your connection is on the geyser tube to the bottle, the higher your eruption will go.

Step 3: Slide a toothpick through the geyser tube

This part can be a little bit tricky depending on how thick the construction paper or card stock for your geyser tube is. If you are using standard construction paper, then you should be able to poke your toothpick through the tube and the tape on the outside of the tube fairly easily.

If you are using thicker card stock paper, you may need to use a paperclip or even a small needle to poke a hole through the tube first, and then insert the toothpick through the hole in the tube.

Whatever method you decide to use, make sure to put the toothpick in near the bottom of the geyser tube and just above where the tube connects into the bottle.

Look through the tube and double-check that the toothpick is in going through the center of the tube and sticking out of both sides. It is important to make sure the toothpick is in a spot to keep the Mentos from falling into the soda bottle.

The toothpick will act as the firing pin for the Mentos and soda eruption, so you want to make sure it is in the right spot! You do not want the eruption to fire prematurely and make a mess…trust me I have learned this part from experience!

Step 4: Move to a place away from anything you don’t want to get messy

We are almost ready for the grand finale of this favorite experiment, but before you get too excited and drop those Mentos into the soda bottle you might want to take this experiment outside!

One thing that I have learned in doing this Mentos and Coke Volcano is that no two eruptions are alike. Sometimes a few Mentos can fall into the bottle and some can get stuck in the tube and create a funnel that shoots sticky soda spray 10 or more feet high (I learned this the hard way and gave my house a sticky diet coke bath)!

Other times, when all goes as planned, this geyser tube should create a steady fountain of soda that shoots about 3-4 feet high above the bottle. Bottom line, do this in an area that is okay to get messy and be prepared for anything!

Step 5: Make sure the toothpick (firing pin) is in and ready to hold the Mentos

Now that you are outside, or in a good area to start your reaction, double-check that your toothpick is inserted all the way through the geyser tube. It should be near the bottom of the tube and going through the center to keep the Mentos from falling into the soda pop below.

Since the next step is when our volcano begins to erupt, I highly recommend putting your safety goggles on now before it’s too late!

Step 6: Load Mentos into the geyser tube

Very gently and slowly drop about 5 Mentos into the top of your geyser tube. Mint or fruit-flavored Mentos will work for this reaction, but I prefer to use the mint ones just because I love to save the fruit ones for a little tasty treat!

The toothpick in the bottom of the tube should do its job to stop the candies from falling into the soda, but just be on guard in case a Mento finds it’s way past the toothpick and into the soda. If this happens, your eruption will start prematurely and you will want to get out of the way quickly!

Step 7: Pull the toothpick out of the geyser tube and watch the reaction

As you quickly pull the toothpick out from the geyser tube it will allow the Mentos to drop into the soda and you will almost instantly see your Coke and Mentos Volcano erupt into a brilliant brown fountain!

Hopefully, by this point, you have quickly moved out of the way to a safe and dry viewing distance, or you might get sprayed by some sticky volcanic soda!

The good news is that as long as you don’t mind a little mint flavor in your drink, or a flat soda…then you can pour the remaining soda into a glass and enjoy a little post-experiment refreshment too!

Coke and Mentos Explained:

This Coke and Mentos volcano happens thanks to the reaction between the gelatin and gum molecules in the Mentos and the carbonation in the soda pop. Carbonated soda beverages contain carbon dioxide that is dissolved in the soda and attached to water molecules.

The gelatin and the gum in the Mentos help to break apart the water and carbon molecules that are stuck together in the soda. Another factor that helps the eruption happen with even more force is the fact that the Mentos are denser than the liquid soda and they sink to the bottom.

Mentos also have tons of tiny little microscopic pits on their surface which are a double whammy for creating a great reaction. The tiny little holes on the surface of the Mentos allows a spot for carbon dioxide bubbles to form rapidly, which leads to the eruption.

When the carbon dioxide bubbles form on the microscopic holes in the Mentos, the bubbles rise and push all the soda up and out of the geyser tube with them and creates the Coke and Mentos Volcano that we all love!

Do you have to use Coke to create the Mentos eruption?

Even though this experiment is often referred to as the “Coke and Mentos experiment,” you can actually use any kind of carbonated soda with Mentos to get this stunning reaction. It is true though that some flavors of soda are known to produce better reactions than others.

This is mainly because some sodas have more carbon dioxide in them than others. The carbon dioxide is what creates all the bubbles and creates the pressure to make the fountain of soda.

From my experience, Diet Coke is actually the best option for this Mentos and Coke Volcano for a couple of reasons.

Diet Coca-Cola has a lot of carbonation (carbon dioxide) so it makes the reaction great! There is also less sugar in Diet Coke than other sodas, so it doesn’t get quite as sticky and messy to clean up in the end.

Do Fruit Mentos work with Coke?

Yes! You can use Fruit Mentos or Mint Mentos to create the Mentos and Coke volcano. It does seem like the Mint Mentos react a little more intense with the soda and create a slightly higher fountain of soda though.

I personally prefer to use the Mint Mentos for this experiment to get the biggest and best eruption as possible…and to save the tasty Fruit Mentos for myself since they taste way better than the Mint Mentos!

More Fun and Easy Experiments:

• Rising Water Experiment Step by Step
• Unpoppable Balloon Experiment
• Tornado Experiment

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The Infamous Coke and Mentos Experiment

September 11, 2014 By Emma Vanstone 1 Comment

The science experiments my children talk about for months afterwards are generally the messy ones, like our splatter patterns , glow in the dark oobleck ,  baking soda experiments and the well known coke and mento experiment .

If you try this classic chemis t ry experiment definitely do it outside as it’s VERY messy and sticky. Sometimes you’ll see it called a coke and mento geyse r, as the eruption looks like a geyser!

Coke and Mentos Experiment

You’ll need:.

Coke or other fizzy soda

Instructions

We dropped two Mentos into a bottle of normal Cola and Diet Cola. I used the cheapest brands available in our local supermarket.

Once you drop the Mentos into the coke, stand back as it’s VERY explosive. The trick is to drop the mento in as fast as you can. If too much of the fizz escapes before you add the mento the reaction won’t be as good.

What happens when Coke and Mentos mix?

There are several theories, but it’s thought that the many small pores on the surface of the mento speed up the release of carbon dioxide (CO 2 ) gas from the soda as they give a larger surface area for the reaction to occur over, causing foam to erupt at a super fast rate.

Which soda works best with Mentos?

Any fizzy drink will produce a similar effect, but diet drinks seem to work best, as we found in our investigation. This is most likely due to the particular chemicals in diet drinks.

The reaction isn’t a chemical reaction but a physical reaction! The molecules haven’t been chemically changed, just re-arranged!

See Steve Spangler for a much more thorough explanation of this very cool experiment .

Does the number of mentos affect the height?

More Mentos candies should mean a better explosion, but there is a limit to how many will actually make a difference. We found 7 to be the maximum number we could drop in at once.

More Coke and Mentos Eruption Ideas

Investigate to find out if the type of fizzy drink matters. Does diet soda make a taller geyser?

Try lots of different sodas and diet sodas.

Test fruit-flavoured Mentos instead of mint flavoured.

Find out if the number of mentos affects the height of the geyser.

Investigate to discover what would happen if you left the top off the Cola for a few minutes before adding the Mento.

Use the reaction to power something? Maybe a LEGO car?

Design a device to drop several mentos into the bottle at the same time. Can you find out what the optimum number of mentos for a 2-litre bottle of soda is?

Last Updated on April 9, 2024 by Emma Vanstone

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Science Sparks ( Wild Sparks Enterprises Ltd ) are not liable for the actions of activity of any person who uses the information in this resource or in any of the suggested further resources. Science Sparks assume no liability with regard to injuries or damage to property that may occur as a result of using the information and carrying out the practical activities contained in this resource or in any of the suggested further resources.

These activities are designed to be carried out by children working with a parent, guardian or other appropriate adult. The adult involved is fully responsible for ensuring that the activities are carried out safely.

Reader Interactions

December 17, 2019 at 7:20 pm

It will also work better the warmer the soda is

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How to Make Your Own Coke and Mentos Volcano With Kids

By: Author Susanne Williams

Posted on Published: December 5, 2020  - Last updated: December 29, 2023

Which child doesn’t like a good explosion?

Then try this fun DIY coke volcano science experiment with your kids.

They will love their explosive STEM project!

All you need are two ingredients for a lot of fun.

Let’s get right into it!

There are affiliate links in this post, meaning, at no additional cost to you, I will be compensated if you click through and take action. As an Amazon Associate, I earn from qualifying purchases.

How Do You Make a Volcano With Coke and Mentos?

Before we start with our coke and mentos volcano instruction, let’s find out which supplies we will need.

Materials You Will Need for the Mentos and Coke Volcano

We used regular coke for the first time for this mentos volcano experiment but then found out that diet soda actually gets you better results.

The larger the coke bottle you choose the bigger your explosion will be. So why not choose a 2L bottle for our mentos soda volcano?

Are you interested in more kid’s activities and arts & crafts? Subscribe to our newsletter now and never miss an update! Click here

Coke and Mentos Volcano Instructions

If you follow our easy step-by-step soda mentos volcano a great explosion will be guaranteed!

Step 1: Prepare your Soda

Open your bottle of soda carefully and position it on even ground so it can not tip over!

Step 2: Prepare Mentos

Now unwrap a roll of mentos.

Step 3: Add Mentos

The goal is to drop the mentos in the bottle at the same time. Which can be tricky!

Once all the mentos are dropped it is time to move out of the way as quickly as possible!

We used our hands to drop the mentos in at once but another method is to roll a piece of paper into a tube big enough to hold the loose Mentos.

Place a card or paper under the roll and put it on top of the bottle opening.

Then you can pull the card and the mentos will drop at the same time into your soda.

Step 4: Eruption

Quickly after all mentos are dropped you can watch your coke explode like a volcano!

Diet Coke Mentos Volcano Tips

• Make sure to try this experiment only together with an adult!
• Be aware that it’s a mess and think carefully about a location where you can place the coke! I recommend doing it outside in an open space with no ceiling or roof!
• The more mentos you use, the better the explosion will be.

The Science Behind Volcanos Out of Coke and Mentos

Before we start any experiment my children and I always talk about our project and I let them make their hypotheses.

After the actual experiment, we talked about their observation and if their hypotheses came true, why or why not that is and the science behind it.

So let’s find out why mentos make soda explode.

When the mentos sink into the coke bottle it creates rising bubbles, while at the same time, the candy forms carbon dioxide bubbles all over their surfaces.

As this happens the rising bubbles react with the carbon dioxide that is still dissolved in the soda and cause more carbon dioxide and bubbles to be freed with the result of a fun eruption.

Did you know STEM Education has many benefits? Read all about them here. Your kids also might enjoy our popular Sherbet Experiment , explore this classic Skittle Experiment , or enjoy this magical Dishsoap Experiment .

Do you want to see the Coke and Mentos volcano experiment in action? Watch this video!

Pin Our Fun Coke Mentos Volcano Experiment

Don’t forget to save our Mentos Coke volcano science experiment on Pinterest for later! Be sure you are following along with Lil Tigers  here .

How did your kids enjoy their own Coke volcano with Mentos candy? Did it work for you? Either way, let me know by leaving a comment below right now. I’d love to hear from you!

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Science project, mentos and diet coke experiment.

Carbon dioxide is the chemical compound that consists of two oxygen atoms bonded to a carbon atom. Carbon dioxide creates the bubbles in soda. The goal of this project is to explore the eruption of carbon dioxide when the candy Mentos dissolves in Diet Coke.

Observe and explain the Mentos and Diet Coke experiment.

• Mentos mint candy
• A variety of containers with varying sized opening
• A narrow test tube wide enough to fit the candy [Klutz and others make a delivery contraption that is easier.]
• Stack the Mentos candies (approx. half a roll) in the test tube.
• Cover the opening of the test tube with an index card or similar slim, small paper.
• Invert the test tube, holding the cover in place.
• Place the soda bottle outside in and area that can get dirty.
• Open the soda and place the index card over the bottle opening.
• Pull the index card away swiftly, dropping the candies into the soda. Be prepared: the eruption happens quickly, so back up fast!
• Observe the eruption—height, trajectory, duration, etc. Record your observations in a logbook.
• Repeat the process, varying the opening that the soda erupts from. For example, cut the bottle top to increase the diameter an inch or more. Alternatively, dispense the soda into a vase or pitcher. Or, attach plastic piping or tubing to extend the opening’s neck. Be sure to measure the diameters for each eruption.
• Observe each eruption, recording the details and compare the results.

This experiment can be visually displayed with photos or videos of the event and a graph of the table’s results.

The Mentos candy gelatin and gum arabic create an energy that breaks the surface tension of the soda. The pits on the candy coating act as conduits for carbon dioxide bubbles that form immediately when the candy hits the soda, increasing its fizziness. When the candy hits the bottom of the bottle, the gas is released and pushes the soda from the bottle up in the air in an amazing eruption!

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Science of Mentos-Diet Coke explosions explained

By Hazel Muir

12 June 2008

Scanning electron microscope images show the roughness of mint Mentos (top and bottom left) and fruit Mentos (top and bottom right), the scale bars representing lengths from 20 to 200 micrometres

(Image: T Coffey/Dewel Microscopy Facility/AAPT)

The startling reaction between Diet Coke and Mentos sweets, made famous in thousands of YouTube videos, finally has a scientific explanation. A study in the US has identified the prime factors that drive the fizzy plumes from Coke bottles: the roughness of the sweet and how fast it plummets to the bottle’s base.

“If you drop a pack of Mentos into a bottle of Diet Coke, you get this huge fountain of spray and Diet Coke foam coming out,” says Tonya Coffey , a physicist at Appalachian State University in Boone, North Carolina. “This was a good project for my students to study because there was still some mystery to it.”

When mint or fruit Mentos are dropped into a fresh bottle of Diet Coke, a jet of Coke whooshes out of the bottle’s mouth and can reach a height of 10 metres. Theories abound as to why this happens, with some bloggers speculating that it is an acid-base reaction because Coke is acidic.

Experiments in a 2006 edition of the Discovery Channel programme Mythbusters suggested the chemicals responsible for the reaction are gum arabic and gelatine in the sweets, and caffeine, potassium benzoate and aspartame in the Coke. But there have been no rigorous scientific studies of the reaction until now.

Fizzy liquids

To find out more, Coffey and a team of students tested the reactions between Diet Coke and fruit Mentos, mint Mentos, and various ingredients such as other mints, dish-washing detergent, table salt and sand. They also compared reactions using other fizzy liquids such as caffeine-free and sugary colas, as well as soda water and tonic water.

All the reactions took place in a bottle angled at 10° off vertical and the fountain trajectories were recorded on video. The team also investigated the total mass lost in the fountain and the influence of the sweet’s surface roughness.

The results showed that Diet Coke created the most spectacular explosions with either fruit or mint Mentos, the fountains travelling a horizontal distance of up to 7 metres.

But caffeine-free Diet Coke did just as well, suggesting that caffeine does not accelerate the reaction, at least at the normal levels in the drink.

Measurements of the pH of the Coke before and after the experiments showed that its acidity did not change, ruling out the idea that a simple acid-base reaction drives the fountains.

Instead, the vigour of the jets depends on various factors that affect the growth rate of carbon dioxide bubbles.

The rough, dimply surfaces of Mentos encourage bubble growth because they efficiently disrupt the polar attractions between water molecules, creating bubble growth sites.

Rough candy

“Water molecules like to be next to other water molecules, so basically anything that you drop into the soda that disrupts the network of water molecules can act as a growth site for bubbles,” Coffey told New Scientist . “And if you have rough candy with a high ratio of surface area to volume, then there’s more places for the bubbles to go.”

Low surface tension also helps bubbles grow quickly. Measurements showed that the surface tension in water containing the sweetener aspartame is lower than in sugary water, explaining why Diet Coke creates more dramatic fountains than sugary Coke.

Another factor is that the coatings of Mentos contain gum arabic, a surfactant that further reduces surface tension in the liquid. Rough-surfaced mints without the surfactant did not create such large fountains.

Mentos are also fairly dense and sink rapidly, quickly creating bubbles that seed further bubbles as they rise. Crushed Mentos that fell more slowly created puny fountains that only travelled about 30 centimetres.

“Middle-school teachers are getting their students out onto the baseball field next to their school and doing this reaction, and their students love it,” says Coffey. “It’s a great way to get students excited about science and learn something new.”

Journal reference : American Journal of Physics , DOI: 10.1119/1.2888546

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