How to Make a Baking Soda Volcano

Step-By-Step Instructions for a Classic Science Fair Project

Children pouring vinegar into a volcano experiment

busypix / Getty Images

The baking soda and vinegar volcano is a classic science project that can help kids learn about chemical reactions and what happens when a volcano erupts. While it's obviously not the real thing, this kitchen equivalent is cool all the same! The baking soda volcano is also non-toxic, which adds to its appeal—and it only takes about 30 minutes to complete.

Did You Know?

  1. The cool red lava is the result of a chemical reaction between the baking soda and vinegar.
  2. In this reaction, carbon dioxide gas is produced, which is also present in real volcanoes.
  3. As the carbon dioxide gas is produced, pressure builds up inside the plastic bottle, until—thanks to the detergent—the gas bubbles out of the mouth of the volcano.

Volcano Science Project Materials

  • 6 cups flour
  • 2 cups salt
  • 4 tablespoons cooking oil
  • warm water
  • plastic soda bottle
  • dishwashing detergent
  • food coloring
  • vinegar
  • baking dish or another pan
  • 2 tablespoons baking soda

Make the Chemical Volcano

  1. Start by making the cone of your baking soda volcano by mixing 6 cups flour, 2 cups salt, 4 tablespoons cooking oil, and 2 cups of water. The resulting mixture should be smooth and firm (add more water if needed).
  2. Stand the soda bottle in the baking pan and mold the dough around it to form a volcano shape. Be sure not to cover the hole or drop dough inside the bottle.
  3. Fill the bottle most of the way full with warm water and a bit of red food coloring. (You can do this prior to sculpting the cone as long as you don't take so long that the water gets cold.)
  4. Add 6 drops of detergent to the contents of the bottle. The detergent helps trap bubbles produced by the chemical reaction so you get better lava.
  5. Add 2 tablespoons baking soda to the liquid in the bottle.
  6. Slowly pour vinegar into the bottle, and then watch out...It's eruption time!

Experiment With the Volcano

While it's fine for young explorers to tackle a simple model volcano, if you want to make the volcano a better science project, you'll want to add the scientific method. Here are some ideas for different ways to experiment with a baking soda volcano:

  • Make a prediction about what happens if you change the amount of baking soda or vinegar. Record and analyze the effect, if any.
  • Can you think of ways to change the volcano to make the eruption go higher or last longer? This might involve changing the chemicals or the shape of the volcano. It helps to record numerical data, such as the volume of liquid, the height of the "lava," or the duration of the eruption.
  • Does it affect your volcano if you use a different kind of chemical to color the volcano? You could use tempera paint powder.
  • Try using tonic water instead of regular water to get a volcano that glows under black light.
  • What happens if you substitute other acids instead of vinegar or other bases instead of baking soda? (Examples of acids include lemon juice or ketchup; examples of bases include laundry detergent and household ammonia.) Use caution if you decide to substitute chemicals because some mixtures can be dangerous and may produce hazardous gasses. Never experiment with bleach or bathroom cleaners.
  • Adding a bit of food coloring will result in red-orange lava! Orange seems to work best. Add some red, yellow, and even purple, for a bright display.
mla apa chicago
Your Citation
Helmenstine, Anne Marie, Ph.D. "How to Make a Baking Soda Volcano." ThoughtCo, Apr. 5, 2023, Helmenstine, Anne Marie, Ph.D. (2023, April 5). How to Make a Baking Soda Volcano. Retrieved from Helmenstine, Anne Marie, Ph.D. "How to Make a Baking Soda Volcano." ThoughtCo. (accessed June 9, 2023).