Are you looking for a fun, outdoor STEM activity for the kids? Try making these baking soda dinosaur eggs- and hatch them out with vinegar!

Baking soda and vinegar has been a combination loved by kids for generations. But it’s missing one thing- dinosaurs!

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All of my kids have been obsessed with dinosaurs. Dinosaur books. Dinosaur toys. Dinosaur crafts. Dinosaur documentaries. They just LOVE everything about them. 

These fun baking soda dinosaur eggs combine everyone’s favorites for a fun STEM activity for kids that everyone will love!

They are quick and easy to make and will provide a ton of outdoor fun for all. 


baking soda dinosaur eggs a stem activity


Fizzing Baking Soda Dinosaur Eggs Recipe

This is a super simple recipe- only a handful of ingredients that you probably already have on hand in your kitchen!

Here’s what you need:

  • Baking soda (I used about 2 cups for about 7-8 eggs)
  • Cornstarch (I used less than 1/2 a cup)
  • Water
  • Optional: food coloring


That’s all you need to make the actual eggs, but you will also need the following to complete the whole activity:

  • Ziploc bag
  • Small dinosaurs
  • White vinegar (lots of it!)
  • Eye dropper
  • A tray to contain the mess


dinosaur eggs made out of vinegar with a jar of vinegar and a dropper


How to Make the Baking Soda Dinosaur Eggs

These eggs only take a few minutes to put together and then an hour or so drying/freezing time. Here’s how to mix them up:

Place your baking soda in the ziploc bag. Measurements aren’t real important, since it’s consistency you are looking for. 

Add in a little corn starch. I used less than 1/2 cup for over 2 cups of baking soda. Mix the 2 together well. 

If you want to color your eggs, go ahead and drip a little color in the bag at this point. 

Next start adding water, a couple tablespoons at a time. Mix well in between each addition. 

Keep adding water until your mixture resembles a soft dough that will hold together and not crumble. It’s better to be a little on the wet side than to dry. But if it completely melts when you put it down, you might need to add more baking soda. 


baking soda eggs being formed around a tiny toy dinosaur


Once you have mixed the correct consistency, let’s make the eggs!

Take a small ball of the mixture and pat it out into a circle, about the size of your dinosaur figure. 

Press the figure into the mixture and add more on top to cover the dinosaur completely. Then gently mold the baking soda mixture around the dinosaur until it’s somewhat egg shaped and it conceals the dinosaur completely. 

Place the finished eggs on a plate or tray and freeze them for at least an hour. 

*Note: You can also let these eggs air dry. It will take overnight at least, so if you, and your kids, have the patience for that feel free to dry them until they are hard! But if you have impatient people in your home- freezing is the way to go!


baking soda dinosaur eggs being hatched using a dropper of vinegar


Hatching Baking Soda Dinosaur Eggs!

Once the baking soda eggs are completely hardened, it’s time to hatch them!

For this part of the activity you need your eggs, a container of vinegar, an eye dropper, and a tray to contain the mess. 

You can do this activity indoors, but I highly recommend doing it outside where you won’t worry about the mess or the volcanic eruptions that tend to happen when vinegar and baking soda get together. 

The idea is simple, use the dropper to drip vinegar onto the baking soda eggs, and as the reaction occurs the baking soda will fizz away revealing the tiny dinosaur inside the egg!


playing with baking soda eggs on a tray with vinegar


Alternative Ways to Explore Baking Soda Eggs:

This STEM activity is all about the experience and part of that means that kids have the freedom to experiment! Do don’t try to control the situation and only allow them to safely drip vinegar onto the eggs over the tray. 

There are plenty of other ways to explore! Such as:

Drop the baking soda eggs directly into vinegar. This will produce a somewhat large reaction, the jar is likely to overflow sending bubbles everywhere!

Use your hands. Kids can also use their hands to help the dinosaurs hatch. They can use vinegar on their hands or a combination of the dropper and their fingers. 

Fill plastic Easter eggs with the mixture and dinosaurs and freeze.  This is a fun alternative to molding the eggs yourself. They can be hard to open once frozen, but that can add to the fun too!

Use leftover baking soda “sludge” to make more eggs! Once the eggs have all hatched, the kids can explore the remaining wet baking soda. It’s like a non-Newtonian fluid and you can pack it (and dinosaur figures) into plastic Easter eggs or just squeeze and squish in your hands. 

Use MORE vinegar.  Just bring the whole jug out and keep adding more! Once the bubbles die down, add more vinegar to start it up again!


Looking for more Baking Soda and Vinegar Activities? Check out the activities below:

7 Baking Soda and Vinegar STEM Activities for Kids

7 Baking Soda and Vinegar Activities for Kids!


Try These Other Activities:

How to Make Fizzing Baking Soda Paint (a STEAM Activity)

Simple Acids and Bases Science Experiment to Do With Kids

Oil and Water Sensory Bag

Fun Chemical Reaction Experiment for Kids That Gives Off Heat!



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