How to make a volcano: Preschool science experiment

Making a volcano experiment is a fun and easy way to teach your kids of all ages about science. All you need is baking soda, vinegar, and a little creativity! This is a great simple science experiment for kids of all ages, including pre-schoolers. And the best part is that it never gets old – You can make simple volcanoes with an empty soda bottle, or get creative and make them with dirt, sand, or snow!

Below are the steps to make your own volcano experiment at home. You can jump right to the instructions if you want.

plastic dinosaurs in front of a paper mache volcano

What is a volcano experiment for kids?

Essentially, it’s where you use your creativity to create a volcano base and you create a chemical reaction by mixing a baking soda slurry with vinegar. The reason there’s an eruption is that baking soda (sodium bicarbonate) is a base, but vinegar (acetic acid) is an acid. First, the reaction makes carbonic acid. This is an unstable reaction, so it breaks down into a gas called carbon dioxide and water… This is the bubbly and fizzy reaction you see! The foamy bubbles are created as this reacts with the soap, making it bubble up and overflow.

Download a scientific method worksheet before starting

This is totally optional, but you may want to head over to my TpT store and download the Scientific Method worksheet for free. This way, you can emphasize key learning moments while introducing your preschooler to the scientific method. By practicing this, they will become confident in their ability to hypothesize, test, and evaluate experiments!

Plus, if you write down the step-by-step instructions and tuck this away in a folder for later, they can re-create the same activity another time.

baking soda and vinegar volcano made of snow

Making a baking soda vinegar volcano: What you’ll need

I’ll list the basic ingredients and materials for a volcano, but remember – For the base, you can get as creative as you want! I’ll share some ideas for that below.

Here is everything you will need to make your own volcano experiment at home:

Materials:

  • 1/2 cup baking soda
  • 1/4 cup warm water
  • 1/2 cup white vinegar
  • 1 tablespoon dish soap
  • A container for the “lava” to pour out of (your base)
  • A container to mix the baking soda/water/dish soap
  • A spoon for mixing

Optional Ingredients:

  • Kid’s choice of food coloring
    • I usually let the kiddos add this and we come up with a number of drops that makes sense! Usually 5 or so is good
  • Pop rocks
    • These add a fun popping sound to the volcano! If you find some, they’re a super fun addition, but even without them this volcano science experiment is pretty cool

Do I need dish soap and food coloring?

Not at all. The food coloring just makes things more exciting. Usually, I’ll opt for red food coloring so it looks like lava pouring out of the top. But if I’m doing this with a small group then I’ll let the kiddos decide.

As for the soap, adding it increases the reaction time and creates more bubbles than without. But, that being said, I did this experiment for many years without the soap and it was just as fun!

baking soda and vinegar volcano bubbling

How to make a volcano

This baking soda volcano is super easy! With only 3 supplies needed, it’s also one of my favorite science experiments. All you need to do is make a baking soda slurry then pour the vinegar in at the end and you’ll have volcano eruptions!

Instructions:

  1. In a small container, mix the baking soda, food coloring, dish soap, and water with a spoon.
    • Add all of the other ingredients before the water! You only want to put enough water that you can pour your baking soda slurry.
  2. Pour your slurry into the volcano base (or, if you built your base you could just put this cup right inside.
  3. Finally, pour in the vinegar!
  4. Stand back, your vinegar reaction will make your volcano erupt!

What do I need for the volcano base?

In the photo above, we went all out and made our own paper mache volcano. Am I usually this extra? Nope! But, there was a pretty intense heat wave at the time and we needed a good activity to keep us busy over the week. Making this meant we could spend lots of time designing and crafting before we actually saw an eruption.

As for the base, you can use whatever you have available! Here are some ideas to get you started though:

  • Dirt/sand volcano: Next time you build a sand castle, try building a functioning volcano! Just build your base around an empty cup or soda bottle
  • Playdo/plasticine volcano: Same idea – Build your base around an empty cup or empty soda bottle
  • Snow volcano: So, after making a dirt volcano and graduating to the paper mache version months later, the kiddos were still excited about this well into the winter months. Naturally, we had to try to make a snow-cano too! It worked just as well as any other
  • Paper mache: Again, this is very extra. But, if you want a minimum 3 day craft, it’s totally worth it! We built the base, painted it, glued on accessories like DIY trees and mini dinos, then on the final day made it erupt with the baking soda and vinegar mixture! Totally worth the wait.

What do I do when the volcano stops erupting?

Unfortunately, your carbon dioxide mixture won’t erupt forever! In fact, the eruption time is pretty short. But, the nice thing about this easy volcano experiment is it’s easy to re-make.

First, try adding vinegar to the dormant volcano. It will likely cause another eruption because there will be a leftover baking soda mixture in the bottom of the container.

Then, try adding more baking soda. You can always mix vinegar in after to use it all up, but I find that even though kiddos love watching this fun activity, they’ve usually had enough fun after a few eruptions!

Should I do this experiment outside or inside?

Volcano science should probably be an outdoors experiment if you can. Because you’ll probably add red food coloring, for example, you don’t want your counters to be left orange from a stain. And, the eruption can be pretty messy! It’s easier to deal with inside than wiping up the vinegar and baking soda from the floor.

Also, do this experiment in a well-ventilated area if you choose to stay indoors. Realistically, you could make the baking soda and vinegar volcano in a tub to contain the mess. But, since you create carbon dioxide when the vinegar reacts with the baking soda, you’ll want to avoid breathing it in.

Conclusion

We hope you’ve loved this easy science experiment! Kiddos love to watch the lava ooze out of their homemade volcano and love hearing the chemical reaction take place as the baking soda and vinegar erupt.

This experiment is great for children of any age because it can be as basic or as complex as you make it. Kids can choose to make a base out of an empty water bottle and simply enjoy watching the volcano erupt, or you can get super scientific about it. For example, you could make this for a science fair project where the kids go into detail about the chemical reaction happening here while comparing it to real volcanoes. Or, you can use it as an experiment during a unit where you are exploring rocks and volcanoes.

However you choose to incorporate this easy baking soda volcano into your science time, we would love to see what you created!

baking soda and vinegar volcano after eruption
Reminder: Do this experiment outside! It gets messy.

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Elke Crosson
Elke Crosson

Elke Crosson has her BA in International Relations with a minor in Spanish at UBC (Okanagan). She is currently in her second year of the Master of Teaching program at the University of Toronto, with dreams of becoming an elementary-level teacher.