Have you ever made oobleck before?
Oobleck is cornflour and water that when mixed together can act like a solid and a liquid. We’ll show you how to make oobleck. This oobleck recipe is simple and fun to do. It’s a lot easier than making slime and kids love playing with it!
What is Oobleck?
Oobleck isn’t a liquid or a solid, it’s a non-Newtonian fluid. At times, it may seem like a solid or a liquid but it acts differently than a normal solid or liquid. Making oobleck is a great science experiment to show how changes in pressure can change the properties of some materials. Sort of like how temperature changes the properties of water. Cold or freezing temperatures turns water into ice. Whereas warm temperatures melts ice and turns it into a liquid.
Here’s how to see the difference you can make by applying pressure to your oobleck: Apply quick pressure with a spoon and this will increase the oobleck’s viscosity by forcing the cornflour particles together. It will feel hard and you can even form the oobleck into a ball if you try with your hands. Release your pressure or slowly dip your spoon into the mixture and it will act like it’s more like water. By moving slowly, the cornflour particles have time to move out of the way.
If you want to pair this activity with a book, you can read the Dr Seuss book, Bartholomew and the Oobleck.
How to Make Oobleck
Oobleck is a mixture of cornflour and water. Two ingredients you likely already have in your kitchen cupboards. You can also add some food colouring to it, we made ours pink, as that's what the two-year-old wanted! You can leave it without colour or make any colour you like. This simple oobleck recipe is easy to do and kids will love touching and playing with it. If your kids love to play with slime then they will also love oobleck.
Here’s what you’ll need to make this oobleck recipe:
2 cups cornflour
1 cup water
food colouring (optional)
How to Make Oobleck: Step-by-Step Instructions
1. Mix 2 cups of cornflour to 1 cup of water in a bowl. Mix the cornflour and water until your oobleck is formed. Tip: If you would like to colour your oobleck, add your food colouring to your water and then mix with the cornflour.
2. If you find the mixture is a little too watery and not forming into a solid when you pull the oobleck out of your bowl, then add more cornflour. If you find the mixture is not dripping like a liquid, add a little more water. Just keep experimenting until you get the consistency of oobleck.
Take a potato masher or spoon and hit the top of the oobleck quickly. You’ll notice the spoon or utensil will bounce off, giving the appearance that the oobleck is a solid. As mentioned above, this is because the pressure forces the cornflour particles together increasing the oobleck’s viscosity. Then move slowly into the oobleck with your spoon and this will allow the particles time to move out of the way which will let you dip it into the oobleck.
Pick up the oobleck with your hands and form a ball. Then let go of the ball and watch it melt into your hands like magic!
Cutting Oobleck. We used a cake cooling rack to put a solid ball of oobleck on then as it turned into a liquid we used scissors to cut the drips.