by Emma Louise Oldham October 26, 2019

Don't let your carved pumpkins go to waste. They make fantastic volcanos! Turn your leftovers into an erupting fun science project.


What you need:

  • One small pumpkin (the bigger you use, the more of the other ingredients you need to add)
  • Vinegar
  • Food coloring (optional)
  • Dish soap
  • Water

What to do:

Step 1: If your pumpkin isn’t hollowed out, make sure you do this first (with the help from an adult). If your pumpkin is already hollowed out, this is a great way to re-use your pumpkin before it ends up in the compost. 

Step 2:Add one cup of warm water into the centre of the pumpkin. Add ½ cup of natural food dye. Add four to five drops of dish soap and two tablespoons of baking soda. 

Step 3:When when you are ready for the eruption, add 1/4 cup of vinegar. ERRRUUUPPPPTTIIOOOOONNN! How fun is that? If nothing happens, try adding some more baking soda. 

Step 4: Experiment with different amounts of baking powder and vinegar to see how it affects your eruption. Change colours by using different food dyes. The pumpkin also makes a great cauldron. Why not mix up some spooky potions? 

Science Explained

What is happening? The baking soda is a base and the vinegar is an acid. When they combine, a chemical reaction takes place and gas is produced. The gas is carbon dioxide which fizzes and bubbles.


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