How To Make Oobleck

Making oobleck is a great fun activity and science project that we love.  With only two ingredients (three if you want some colour) you can make oobleck, a non-Newtonian fluid that acts like a liquid and a solid at the same time.

Ingredients to Make Oobleck

1 cup of water

1 ½ to 2 cups of cornstarch

Liquid food colouring (optional)

Making Oobleck


  1. In a large bowel pour 1 ½ cups of cornflour.
  2. If you are using food colouring add it to your water
  3. Slowly add the water mixing as you add.  Keep adding water until the mixture becomes thick.

If the mixture is too thick add more water and if the mixture becomes too gooey add some more cornstarch.

The Fun Part

Try squeezing the oobleck in your hand and it feels like a solid ball but if you open your hand it will flow between your fingers like liquid.  It is an amazing substance.

Having fun playing with Oobleck slime.

The Science

Oobleck is a non-Newtonian fluid, a term for fluids that change viscosity (how easily they flow) under stress. When you run your fingers slowly through the mixture or allow it to flow between your fingers it acts like a liquid but apply rapid force, and it solidifies and hardens like a solid.

Clean Up – How to Dispose of Oobleck

DO NOT pour down the sink as it will clog your drain.  Dispose of the it by putting into a bag and then into the waste bin.  Alternatively if you leave it long enough it will dry out again and then be easier to dispose of.

Have fun with your Oobleck slime.