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How to Make Jello Worms for Halloween

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Want to know how to make Jello worms? Do the Jello straw challenge and jelly straw challenge and learn a bit of science along the way! This Jello science experiment is a blast!

Halloween STEM activities are the best way to celebrate the holiday as far as we’re concerned.

But did you know that there are scientific principles behind common Halloween decorations?

Take Halloween jello worms.

These worms are popular because they are jiggly, gross, and delicious, which make them perfect for any Halloween party or as part of Halloween sensory ideas.

Want to know how to make Jello worms? Do the Jello straw challenge and jelly straw challenge and learn a bit of science along the way! This Jello science experiment is a blast!

But there is also quite a bit of science behind how gelatin transforms into a semi-solid when cooled.

After you learn how to make Halloween jello worms, take a minute to discuss the science of gelatin with your kids.

How to Make Jello Worms

jello worm science project for kids

If you have always wanted to make Halloween jello worms but never have, once you find out the science behind the experiment, you’ll just HAVE to make it!

You can also use these directions to make your own Jello straws for the jelly straw challenge (watch the video to see how to do the challenge!)

halloween stem challenge cards

Don’t miss the complete list of Halloween science experiments!

Use these simple worms to make your own Halloween jello worms like a mad scientist!

Jello Worm Science

jelly straw challenge

Jello worms are hardened using gelatin. Gelatin is made from collagen, which is a component of animal connective tissue.

When gelatin is heated, it dissolves into the surrounding liquid because collagen fibers are relatively weak.

But when the mixture cools, it tries to find the bonds contained in the original helical structure of collagen.

This forms into a gel. The gel is considered a viscoelastic material with some solid properties. This makes it ideal for mimicking the attributes of a wiggly, slimy worm.

What you’ll need to how to make jello worms

halloween stem challenge cards

How to make jello worms with straws

Follow along to make your own Jello straws for the jelly straw challenge! Learn how to make Jello worms like a pro!

Day 1

If you have always wanted to make Halloween jello worms but never did, once you find out the science behind the experiment, you'll just HAVE to make it!

We kept our recipe super simple. We dumped the water, flavored gelatin, milk, and food coloring all together in one pot.

We chose the combination of grape and red food coloring to get realistic-looking worms.

In real life, these worms are slightly more clay color than the bright red they look here.

Heat the mixture until it just boils. Add the unflavored gelatin slowly while stirring to prevent any lumps from forming.

jello straw challenge

Cool the mixture in the fridge for 20 minutes.

While the mixture is cooling, fill your jar with straws.

When the mixture is cool, poor it into the straws. For some reason, it doesn’t matter if you actually fill the straws. They fill from the bottom up.

Place your jar in the fridge for 24 hours.

Day 2

If you have always wanted to make Halloween jello worms but never did, once you find out the science behind the experiment, you'll just HAVE to make it!

Run hot water over the bottom of the jar to loosen the gelatin.

If it is stubborn (ours was), run a knife around the edge to encourage the gelatin to release. Place the giant straw bundle in a bowl.

Pull apart the straws. Remove the jello from between the straws and use it to make the jello brain recipe.

Pick up one of the straws and run it under hot water. You’ll know it’s ready when the worm starts to peek out of the bottom of the straw.

Squeeze the end of the straw and gently push the worm out of the straw from the top to the bottom.

jello stem activity for kids

If your straw was appropriately heated, it will slide right out without breaking.

But, if it was not heated enough, it will squish as you press the straw and break into pieces. So, make sure you aren’t impatient.

Once de-strawed, place your jello worms into a bowl and enjoy your gross dessert while discussing how collagen fibers work.

halloween stem challenge cards

More Halloween STEM Activities

We also have Halloween STEM activities for kindergarten, Halloween STEM for first grade, Halloween STEM for 2nd grade, Halloween STEM for 3rd grade, Halloween STEM for 4th grade, Halloween STEM ideas for 5th grade, and middle school Halloween STEM activities!

Zombie paper plate craft

Find more amazing Halloween STEAM activities in the Spooky Science e-book!

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