Let it Fizz!

Bored of regular old sidewalk chalk? Try fizzing sidewalk paint!


  • Large mixing bowl
  • Spoon/spatulas
  • 1 box of baking soda (1 lb. box) 
  • ½ cup of cornstarch
  • Very warm water
  • Several containers or an ice cube tray/muffin tin to hold your chalk paint mixture (think one container per color)
  • Food coloring
  • Paint brushes
  • Spray bottle filled with vinegar (turkey baster and a container of vinegar works as well)


  1. In a large mixing bowl, add the baking soda and cornstarch 
  2. With your spoon mix together 
  3. Add water and stir
    1. Start with a small amount of water and add it until it resembles pancake batter
  4. Add the mixture into several containers
  5. Add a couple of drops of food coloring into their designated containers
  6. Head outside with your colored mixtures, paintbrushes, spoon and spray bottle filled with vinegar
  7. Start painting, drizzling and splattering
    1. You can use a paintbrush or a spoon to drizzle or splatter the paint
    2. If your paint dries out while you’re painting add some more water
  8. Once you have completed your creation, get ready to FIZZZZZ!
    1. Spray your creation with vinegar and see science happen!

Activity by Erin Bigelow, Upham Site Coordinator

Photo Credit & Inspiration: www.simpleplayideas.com

Posted in Activities, After School, Art, At Home, STEM, Upham.