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Fizzing Slime (Erupting Slime)

This homemade fizzing slime combines a classic slime recipe with a baking soda and vinegar chemical reaction for an exciting STEM activity kids love. Watch it bubble, foam, and erupt before stretching it into fun homemade slime.
Print Recipe
Prep Time 10 minutes
Course: Kids Activity
Cuisine: STEM Activity
Ingredients Equipment Method Notes

Ingredients
  

Slime Base
  • ½ cup white school glue
  • 2 tablespoons baking soda
  • Food coloring a few drops
Fizzing Activator
  • 1 tablespoon saline solution must contain boric acid
  • ¼ cup white vinegar
  • Food coloring optional, for color-changing slime

Equipment

  • Large mixing bowl
  • Small bowl
  • Measuring cups
  • Measuring spoons
  • Mixing spoon

Method
 

Make the Slime Base
  1. Pour the white school glue into a large bowl.
  2. Add several drops of food coloring and stir until evenly combined.
  3. Mix in the baking soda until fully incorporated.
Make the Activator
  1. In a separate small bowl, combine the vinegar and saline solution.
  2. If desired, add a second food coloring to create a color-changing eruption.
Create the Eruption
  1. Slowly pour the activator into the slime base.
  2. Watch the mixture bubble, fizz, and erupt as the vinegar reacts with the baking soda.
Finish the Slime
  1. Allow the reaction to continue until the bubbling slows.
  2. Once most of the vinegar has reacted, knead the mixture with your hands until it becomes smooth and stretchy.
  3. Enjoy your homemade fizzing slime!

Notes

Be patient before kneading. If the slime still feels very wet, the vinegar may still be reacting with the baking soda.
Do not add extra vinegar. Once all of the baking soda has reacted, leftover vinegar can break down the slime and make it sticky.
If making color-changing slime, use one food coloring in the glue mixture and another in the vinegar mixture. Store slime in an airtight container for several days of play.