Sensory Science Rainbow Oobleck

Have you ever made oobleck before? Rainbow oobleck, also known as magic mud, is one of the coolest and easiest sensory science experiments!

For scientists at Discovery Place Science, playful experimentation with oobleck is a great way to explore the properties of liquids and solids. A solid maintains its own shape, whereas a liquid will take the shape of its container.

Oobleck is made by combining a solid and liquid, but the resulting mixture is a bit of both states of matter! Oobleck is an example of a non-Newtonian fluid, a substance that acts like both solid and liquid. Head to the kitchen and prepare to get a little messy with this hands-on experiment!

Age range: Preschool – Elementary School
Prep time: 5 minutes
Learning time: 20-40 minutes

Food coloring or liquid watercolors
Mixing bowls (or cups) and utensils
Large container, bin or tray
Measuring cups
Glitter, beads or small toys (optional)

Note: When dyed with food coloring, rainbow oobleck is non-toxic and completely safe for babies and toddlers. Older kids and adults can experiment with liquid watercolors to create more vibrant oobleck.


  1. Collect and arrange oobleck materials. Six bowls or cups are required for standard rainbow oobleck, but you can make as many or few colors as desired.
  2. Measure and pour equal amounts of water into each bowl. The water amount depends on how much oobleck you want to make, but 1/4 cup water per bowl is a good starting amount.
  3. Mix food coloring (or liquid watercolor) into water, so each bowl is dyed a different color of the rainbow. The oobleck will be lighter (more pastel) after adding the cornstarch. For more vibrant colors, quite a bit of coloring (ideally liquid watercolor) is needed.

    Tip: This is a great opportunity to teach kids about color theory and mixing. Before adding dye, ask which colors would make green, orange and purple. Work together to experiment and select dye combinations before mixing each color.

  4. Work cornstarch between your fingers to eliminate all clumps before adding equal parts cornstarch to each water bowl. While there is not an exact ratio of water to cornstarch, the general guideline is to try 1 cup of water for every 1-2 cups of cornstarch. Oobleck is the correct consistency when you can form clumps into solid balls that melt like liquid back into the bowl when you open your hand.
  5. Combine colors to create rainbow oobleck by adding each color to your larger container, pouring from one side to the other. Be prepared to do this quickly before the colors spread out.
  6. Add glitter, beads or small toys for texture and explore how oobleck interacts with solid objects.

There are endless ways you can play with oobleck! It is perfect for experimentation, trying different things, observing what happens and figuring out why it works that way. Share your oobleck on social media by tagging @discoveryplacescience.