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How to make borax-free Oobleck Slime step-by-step guide

Follow The Dad Lab's Oobleck slime recipe for gloopy, gooey slime - using just cornflour and water!

Here's a fab gloopy, gooey slime recipe from The Dad Lab, that you can make with your child in approx 25 mins.


The best bit? It's totally borax-free and, in fact, you barely need anything to make it.

What exactly is oobleck slime?

"Oobleck is an example of a ‘shear- thickening’ liquid, which just means that it gets thicker and more viscous when it’s stirred," explains the man behind the TheDadLab, Sergei Urban, in his new book.

"That’s because the tiny grains in the mixture – the grains of cornflour – get locked together when they’re squeezed up against one another.

"Oobleck is an example of what’s called a non-Newtonian fluid. The name comes from Sir Isaac Newton, who studied how normal fluids flow. He found that they keep the same viscosity as they flow, getting neither thicker nor thinner."

What you'll need

  • Two cups of cornflour
  • One cup of water
  • Large bowl

Give yourself 25 minutes to make the slime.

How to make it

oobleck slime

1. Put the cornflour and water together in a big bowl. If you like, you can add food colouring to get colourful oobleck. (That’s what this slushy mixture is often called.)

2. Mix it up by hand. If you still see dry cornflour, add a bit more water.

oobleck slime

3. If you scoop out a handful of oobleck and roll or squeeze it quickly in your hand, it sticks together like putty or clay.

But as soon as you just let it rest in your hand, it turns back into liquid and oozes through your fingers.

oobleck slime

4. Try poking the oobleck in the bowl with a finger: it bounces back, as if the stuff is rubbery, and your finger stays clean.

But stick your finger in slowly and it feels like a runny liquid.

oobleck slime

5. Let the kids play and experiment with it. It’ll be messy!

The (rather slimy) result...

oobleck slime

For more fun family activities, check out @TheDadLab's book - available now on Amazon!

Guide and images by TheDadLab

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