Puking Pumpkin Experiment- Fun Halloween Science

This science experiment is so fun for kids, their reaction is amazing! There’s something hilarious and awesome about a puking pumpkin. It’s such an easy activity, the hardest part is carving the pumpkin!

This classic experiment is a twist on the baking soda and vinegar combination. Similar to our bubbling cauldrons or fizzy dinosaur experiments! One disclaimer- if you are concerned about your grass or yard be sure to use a bucket or do this in a container that’s easy to contain and cleanup!

Safey note- this activity should be done with adult supervision and make sure to do it with kiddos who won’t put the foam in their mouths. Also as a reminder adults should be the ones carving any pumpkins.

What is the Puking Pumpkin Experiment?

This is a simple, Halloween-themed, fizzy science experiment using carved pumpkins. It’s a carved pumpkin filled with baking soda and dish soap that you add colored vinegar to in order to create a foamy explosion! If you don’t have a carved pumpkin with a face you can still make a pumpkin volcano too.

This experiment is great because it’s a fun way to teach kids about the chemical reaction between baking soda and vinegar creating carbon dioxide gas, which makes the bubbles. It’s a basic acids and bases experiment that they’ll definitely remember and that makes science fun!

Supplies You’ll Need

A note on supplies – I did my best to include measurements so you could have an idea of what quantities you’ll need, but really you don’t need to follow them, feel free to just eyeball it or go by trial and error!

• Carved Pumpkin (check out our 13 Halloween free printable carving templates!)
• 2 cups Baking soda
• 2 tbsp Dish soap
• 1 cup Vinegar
• Food Coloring
• Optional tray to contain mess

Step by Step Instructions

Place your carved pumpkin someplace where you’re comfortable with there being a mess. Fill a portion of your pumpkin with baking soda. We used about 2 cups, but you can eyeball this and just dump some in! Try to not let the baking soda run out of the bottom of the pumpkin.

Add 3-4 squirts of dish soap. This is optional, but definitely recommended because it makes it super foamy.

Add a few drops of food coloring to about a cup of vinegar and combine. Slowly start pouring the vinegar solution into the pumpkin and watch the pumpkin puke! You are going to get some fun gasps and reactions from this experiment! After the first round is done add more vinegar and/or dish soap for more foamy pumpkin puking. You can get several rounds out of a carved pumpkin.

Tips for Making a Puking Pumpkin:

• Make sure the pumpkin you carved has the hole at the top. Sometimes we carve from the bottom and this definitely doesn’t work with this experiment. I tried. 🙂
• This can be a fun color learning experiment too by combining different food colorings into the vinegar mixture and seeing what the foam looks like.
• You can try several different rounds to see how the foam changes.
• If you’re wanting to contain the mess, try using a smaller pumpkin too!