How to make oobleck
Looking for a fun activity to do with the kids? Try our simple oobleck recipe for a low-cost craft made with store-bought ingredients.
Is it a rock? Is it a liquid or solid? It’s both! Making your own oobleck is a simple, inexpensive science activity that only requires a few kitchen ingredients and is sure to captivate your child.
Oobleck may appear complicated, but it is not. It gets its unusual name from a Dr Seuss story, but it’s actually one of the most basic science activities you can do with your kids.
What exactly is oobleck?
Corn flour has a very fine texture, and when mixed with water, the starch particles suspend rather than dissolve. The water surrounding each starch particle allows the mixture to flow smoothly when the oobleck is still or slowly stirred.
When pressure is suddenly applied, such as striking the surface of the oobleck with a spoon or squeezing the mixture, the starch particles compress together, temporarily pushing the water out of the suspension and causing the mixture to behave like a solid. To see the difference, have kids tap their fingers across the surface, then slowly sink their fingers into the mixture.
Our oobleck recipe requires only corn flour and water. You can add food colouring if you want, but it’s not necessary, so don’t worry if you don’t have any on hand.
Oobleck is technically edible, but it tastes awful! It is safe to play with and is an excellent introduction to the world of slime-making for children of all ages. If your kids enjoy squishing oobleck, they might also enjoy squishing our homemade playdough.
What you need
- 50-60ml cold water
- 75g corn flour
- Food colouring (optional)
How to make it
- Pour the cornflour into a mixing bowl and gradually stir in the water. If the mixture appears to be too dry, add a few drops of water. Add more corn flour if it’s too liquid. When the mixture is thick and fluid but begins to tear if stirred quickly, the oobleck is ready.
- As you play with the oobleck, it can dry out. Simply add a few drops of water to loosen it if this happens.
Good to know: Oobleck is messy, so play with it outside or in an easily cleaned area (like the kitchen). Wear aprons and roll up your sleeves. If your oobleck does not solidify, add 12 teaspoons of corn flour at a time until you achieve the desired consistency. Oobleck can be stored for a few days; simply add a little water to the mixture to reactivate it.
