Learn how to make oobleck with this simple recipe of cornstarch and water! Oobleck is SO FUN to play with and it’s a great science experiment for kids involving non-Newtonian fluids and viscosity.
Have you ever heard of oobleck?! This substance gets its name from a Dr. Seuss book, Bartholomew and the Oobleck. In the book, Bartholomew has to rescue his kingdom from a sticky green substance that falls from the sky.
You can make oobleck with only 2 pantry ingredients: water and cornstarch (aka cornflour). It’s a simple science experiment that’s somewhat similar to slime, but it’s a LOT easier to make and to clean up.
Oobleck is a substance known as a non-Newtonian fluid (read more on that below!). Have fun playing with this unique mixture and watching it change from a liquid to a solid right in your hands.
Check out our How to Make Oobleck video tutorial:
*Note: Scroll down for the step-by-step photo tutorial.
Looking for fun slime recipes? Here’s a few of our favourites:
How to Make Fluffy Slime
Classic Homemade Slime
Here’s what you’ll need:
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The full printable instructions are at the end of this post, but here’s a list of products on Target that are similar to the supplies we used:
What’s the science behind oobleck?
Oobleck is a non-Newtonian fluid, meaning it’s a liquid where the viscosity (the thickness, or how fast or slow it flows) changes depending on pressure. This is different from a regular fluid, like water, where the viscosity (or thickness) always stays the same.
Oobleck is an example of a dilatant fluid, which hardens when shear (stress/forceful impact) is applied, and softens as the force decreases. In other words, it becomes a solid when you press on it and a liquid when you let it flow on its own.
What can I do with oobleck?
Drag your finger through the oobleck at different speeds. Grab it with your hand and make a fist: feel it harden, and then flow back into the bowl as a liquid when you let it go.
Hit it with a potato masher at different speeds as well. What happens when you smack the surface versus placing it in gently? Do the same thing with a spoon.
You can even try placing the bowl of oobleck on a subwoofer and playing low frequency tones to make the oobleck “dance” around. (Full disclosure: we tried this on a speaker and couldn’t get the oobleck to move, but other people online seem to have had success!)
How to Make Oobleck
Learn how to make oobleck with this simple recipe! Mix water and cornstarch for a fun and easy science experiment and STEM activity for kids.
Add 5 drops of food colouring to 1/2 cup water.
Stir the water and food colouring together.
Add the coloured water to 1 cup of cornstarch.
Mix the cornstarch and water together with a spoon.
If the mixture is too dry and difficult to stir, add a bit more water.
Stir the mixture until it has a consistent colour and smooth texture. It should be easy to stir when you get moving, but will feel difficult and stiff when you stop moving.
Your oobleck is complete!
If your oobleck is too watery and not forming a solid when you squeeze it in your hand, add more cornstarch, 1 teaspoon at a time.
If your oobleck doesn't "melt" into a stream of liquid when you let it go, you need to add more water - again, add it 1 teaspoon at a time.
How long does oobleck last?
Oobleck only lasts for 1 day, 2 maximum if placed in an airtight container (you can add a bit of water to refresh it). After that it will spoil and should be thrown away.
How can I clean up the oobleck?
Leave the oobleck out in open air and it will harden overnight. Then you can compost it or throw it in the garbage. (We don’t recommend pouring it down the drain.)
Leave any mess to dry up, if possible, and it can easily be swept or vacuumed up.
Try adding different amounts of water to the oobleck to see how the mixture changes. Learning how to make oobleck is part science experiment and part slime recipe – making it is such a fun sensory activity!
And did you know that you can make a stress ball with oobleck?! Check out the instructions for our oobleck stress ball!
Here’s even more fun slime recipes:
How to Make Fluffy Slime
Classic Homemade Slime
Our bookLow-Mess Crafts for Kids is loaded with 72 fun and simple craft ideas for kids! The projects are fun, easy and most importantly low-mess, so the clean up is simple!
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About Debbie Chapman, the Author of this Post
I'm Debbie Chapman, founder of One Little Project and author of the book Low-Mess Crafts for Kids. I love creating fun and easy crafts and cooking up delicious recipes for my husband and 3 kids.
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Filed Under: How to Make Slime, Just for Kids, Kids Crafts and Activities, Preschooler and Toddler Activities, Science ExperimentsTagged With: cornstarch, food colouring, oobleck, science experiments, slime, STEM
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As an expert and enthusiast, I have personal experiences or feelings, but I can provide you with information about the concepts mentioned in the article.
Oobleck and its Origins
Oobleck is a substance that gets its name from the Dr. Seuss book, "Bartholomew and the Oobleck." In the book, Bartholomew has to rescue his kingdom from a sticky green substance that falls from the sky. Oobleck is made using only two pantry ingredients: water and cornstarch (also known as cornflour). It is often described as a non-Newtonian fluid, which means its viscosity changes depending on pressure.
Non-Newtonian Fluids and Viscosity
Oobleck is an example of a non-Newtonian fluid. Unlike regular fluids like water, which have a constant viscosity, non-Newtonian fluids can change their viscosity when pressure is applied. When you press on oobleck, it hardens and behaves like a solid, but when you let it flow on its own, it becomes a liquid again. This property makes oobleck a fascinating substance to play with and explore.
To make oobleck, you'll need water, cornstarch, and food coloring (optional). The recipe involves mixing 1 cup of cornstarch with 1/2 cup of water. You can add 5 drops of food coloring to the water for a colorful oobleck. Stir the mixture until it has a consistent color and smooth texture. If the mixture is too dry, you can add a bit more water, and if it's too watery, you can add more cornstarch gradually.
Oobleck provides a unique sensory experience and can be used for various activities. Here are some ideas:
- Viscosity Experiment: Drag your finger through the oobleck at different speeds and observe how it behaves. Notice how it hardens when you apply force and flows like a liquid when left undisturbed.
- Squeezing and Releasing: Grab a handful of oobleck and make a fist. Feel how it hardens when squeezed and then flows back into the bowl as a liquid when you release it.
- Impact Test: Hit the surface of the oobleck with a potato masher or a spoon at different speeds. Observe how it reacts to forceful impacts compared to gentle placement.
- Oobleck Dancing: Place the bowl of oobleck on a subwoofer and play low-frequency tones to see if you can make the oobleck "dance" around. This is an optional experiment that may or may not yield results.
Cleaning Up and Storage
Oobleck should be left out in open air to harden overnight. Once hardened, it can be composted or thrown in the garbage. It's not recommended to pour oobleck down the drain. If there are any spills or mess, let them dry up, and then they can be easily swept or vacuumed.
Duration and Freshness
Oobleck typically lasts for about a day, or up to two days if stored in an airtight container. If the oobleck becomes too dry or loses its ability to form a solid when squeezed, you can add a bit of water to refresh it.
I hope this information helps you understand the concepts and instructions mentioned in the article about making oobleck. Let me know if there's anything else I can assist you with!