Get ready for some bubbling Halloween magic with this fizzy witch cauldron experiment! This spooky twist on the classic baking soda and vinegar reaction is the perfect mix of science and fun.
With a dash of food colouring, a sprinkle of glitter, and a little bit of “potion-making” magic, kids can watch their mini cauldrons bubble, fizz, and overflow like a real witch’s brew. It’s simple to set up, exciting to watch, and guaranteed to add some spooktacular fun to your Halloween celebrations!
How to Make a Fizzy Witch Cauldron
Materials:
- Baking soda
- Food colouring(Halloween colour of choice)
- Water
- Glitter(to match food colouring)
- Halloween confetti
- Sequins(to match food colouring)
- Vinegar
- Mini witch cauldron
Equipment:
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Eye dropper(optional)
Instructions:
Step 1: Find what you need
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Gather your supplies and materials.
Step 2: Make coloured baking soda
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Pour 3 Tablespoons of baking soda into a bowl. Then add about 7 drops of purple food colouring (or another witchy Halloween colour of your choice).
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Add about 1 teaspoon of water to the bowl with a measuring spoon or eyedropper.
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Stir together until everything is mixed and the baking soda is nicely coloured.(It’s okay if it’s not perfectly even, since the end result will show the colour well, no matter what.)
Step 3: Add in Halloween fun
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Add a matching colour of glitter to the bowl.
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You can also add sequins and/or Halloween confetti. Stir to mix in.
Step 4: Mix the vinegar and add ingredients to the cauldron
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Add a few drops of food colouring to about 2/3 cup vinegar. Stir to combine, mixing in the colour.
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Spoon the baking soda mixture into the mini cauldron.
Step 5: Watch the potion bubble out of the cauldron
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Then slowly pour in the vinegar. You can start with just a bit and watch the reaction. Then keep adding a bit more until there’s no more bubbles.
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Your fizzing witch cauldron is complete!
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Have fun watching the reaction and imagining what kind of potion it is!
Helpful Tips:
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Contain the mess: Place your cauldron on a baking sheet, tray, or inside a glass casserole dish. This will catch any overflowing bubbles and keep your table clean.
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Easy glitter cleanup: To prevent glitter, sequins, or confetti from going down the drain, place a coffee filter inside a strainer. Pour the colourful mixture through when you’re finished with it, and the filter will catch all the sparkly bits. Then you can reuse them or throw them away properly!
Where can I find a mini witch cauldron for this experiment?
You can find mini witch cauldrons online or at the dollar store around Halloween. Party supply stores will also probably have them.
But we actually used a 3D printer to create our own witch cauldrons. We resized the x-axis to 3 inches on this specific pattern:
How does the fizzy witch cauldron experiment work?
The bubbling reaction in the fizzy witch cauldron comes from mixing baking soda (a base) with vinegar (an acid). When these two ingredients combine, they create carbon dioxide gas, which makes all the fizzing, bubbling, and overflowing action that looks just like a witch’s brew.
Adding food colouring and glitter doesn’t change the science — it just makes the reaction more magical and fun! This is a simple STEM activity, introducing kids to basic chemistry concepts as they watch the reaction happening right before their eyes.
Can I re-use the witch cauldron?
Yes! The mini cauldrons themselves can definitely be reused. Just rinse out the leftover fizz after each reaction and start fresh with new baking soda and vinegar.
If kids want to do the experiment multiple times in one sitting, keep the vinegar in a squeeze bottle and refill the baking soda as needed — it’s an easy way to keep the bubbling magic going!
What else can I use to make this bubbling cauldron experiment?
Baking soda and vinegar is a classic choice, but there are other fun ways to get a fizzy reaction. You can drop Alka-Seltzer tablets into water for an instant bubbling effect, or try combining baking soda with lemon juice or citric acid instead of vinegar.
For extra fun, cornstarch can be added to thicken the “potion,” making the bubbling look more like a thick, frothy brew. Each variation gives kids a chance to explore STEM concepts in different ways, while keeping the experiment magical.
This fizzy witch cauldron experiment is a bubbling blend of Halloween fun and hands-on STEM learning. With just a few simple ingredients, kids can dive into the magic of chemical reactions while brewing up their very own spooky potion. It’s messy, exciting, and the perfect way to spark curiosity this Halloween!
Here’s even more fall STEM craft ideas:
