Go Back
Colorful Soap-Foam Explosion Volcano erupting with fluffy rainbow foam during a fun STEM science experiment for kids.

Soap-Foam Explosion Volcano

Create an exciting erupting volcano using a simple baking soda and vinegar reaction. Dish soap traps the carbon dioxide bubbles to produce colorful, overflowing foam that looks just like lava. This safe, inexpensive science activity is perfect for kids of all ages with adult supervision.
Print Recipe Pin Recipe
Prep Time 15 minutes
Cook Time 5 minutes
Total Time 20 minutes
Servings: 1 volcano experiment
Ingredients Method Notes

Ingredients
  

  • 1 small plastic bottle or cup
  • 2-3 tablespoons baking soda
  • 1/2 cup white vinegar
  • 1 tablespoon dish soap
  • Several drops food coloring one or multiple colors
  • Optional warm water
  • 1 small funnel
  • 1 tray or baking pan to catch overflowing foam
  • 1 spoon
  • Optional modeling clay for building the volcano
  • Optional sand for building the volcano
  • Optional small rocks for decoration
  • Optional toy dinosaurs for decoration
  • Optional plastic trees for decoration
  • Optional toy animals for decoration
  • Optional construction paper or cardstock for a paper volcano
  • Optional paint for decorating

Method
 

  1. Build your volcano using modeling clay, damp sand, or rolled cardstock around a small plastic bottle, leaving the bottle opening uncovered.
  2. Place the completed volcano on a tray, baking pan, or outdoor table to catch the overflowing foam.
  3. Pour 2–3 tablespoons of baking soda into the bottle using a funnel if needed.
  4. Add 1 tablespoon of dish soap to the bottle. The soap helps trap carbon dioxide bubbles, creating thick foam.
  5. Add several drops of food coloring. For a swirling lava effect, place different colors around the inside edge of the bottle.
  6. Slowly pour 1/2 cup of white vinegar into the bottle.
  7. Stand back and watch as the reaction creates colorful foam that bubbles up and flows down the sides of the volcano like lava.
  8. Repeat the experiment by adding fresh baking soda and vinegar to create another eruption.

Notes

Decorate your volcano with rocks, toy dinosaurs, trees, or animals before the eruption for extra fun. For larger eruptions, increase all ingredients proportionally. Adding more dish soap creates thicker foam, while slightly warm vinegar speeds up the reaction. A taller volcano can also produce a more dramatic overflow. Adult supervision is recommended, especially for younger children.