Oobleck Slime is an ooey-gooey slime and a fun way to do sensory play with your kids.
It’s quick and easy to make.
You need only two ingredients.
Plus, kids love to help make it too!
Be sure to check out our other fun sensory activities for kids!
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(No shame in that game!)
If you’ve never heard of Oobleck before, it comes from Dr. Seuss’s 1949 book Bartholomew and the Oobleck.
In the book, a boy saves a kingdom from a sticky slime substance, which I’m sure you can guess is the Oobleck.
And while the story is just that – a story – Oobleck is real.
Oobleck is actually a non-Newtonian fluid.
What this means is fluid doesn’t act like a “normal” fluid. Take water, for example.
Instead, non-Newtonian fluids thin and thicken depending on how much force is applied. The fluid can even feel like a solid until the pressure is released.
Trust: the kids will find Oobleck delightful!
However, you can go the simplified route and buy Oobleck on Amazon.
What Ingredients and Materials Do You Need to Make Oobleck Slime?
- 2 cups cornstarch
- 1 cup room temperature water
- Food coloring (optional)
- Glitter (optional)
- Plastic bowl or plastic bin
- Measuring cups
- Marbles, plastic blocks, toy dinosaurs, smooth stones, seashells, (optional)
Step by Step Instructions
- Add a few drops of food coloring and/or glitter to the water.
- Combine cornstarch and water in the plastic mixing bowl.
- Mix with a spoon until Oobleck forms.
Depending on the consistency, you may need to add more water or cornstarch.
- Add a little more cornstarch to the Oobleck if it’s too liquidy.
- Add a little more water to the Oobleck if it’s too thick.
Oobleck should be solid when applying pressure and flow freely like water when left untouched.
FAQ’s about Oobleck
How to Make Frozen Oobleck?
You’ll need everything to make the Oobleck, plus something to freeze it in.
An ice cube tray, silicone molds or a plastic container works fine.
To freeze your Oobleck, pour it into the container and let it freeze. Voila!
The Oobleck feels solid and cold at first but melts fast.
How to Make Glow-in-the-Dark Oobleck Slime?
For glow in the dark Oobleck, you’ll need:
- A dark room or closet (you may want to put towels on the floor!)
- 2 cups cornstarch
- 1 cup tonic water
- 1 tube of glow in the dark paint
- Blacklight (optional)
- Plastic container/bowl
Here’s how to make glow in the dark Oobleck:
- Add cornstarch and an entire tube of paint into the bowl.
- Mix it with the spoon.
- Add tonic water to the mixture and combine.
Your kids will be excited to test out the finished product in the dark room you set up!
Cover the floor with towels, newspaper or a plastic tarp to keep the mess to a minimum.
How to Make Oobleck without Cornstarch?
You can swap cornstarch for another thickening ingredient, like tapioca flour, arrowroot flour, or potato starch.
The measurements are the same regardless of which thickening agent you choose.
Can you Make Oobleck with Flour and Water?
No, you can’t make Oobleck with standard wheat flour and water.
However, you can make the gooey substance with certain flours, like arrowroot and tapioca flour.
How Long Does Oobleck Slime Last?
Oobleck lasts for about one day in an airtight container inside the refrigerator.
You’ll need to toss it out after that because it’ll start to grow mold.
How to Clean Up Oobleck?
There are three ways you can clean up and throw away your Oobleck:
- Put Oobleck into the garbage bin
- Dry it out overnight, then break into bits with a spoon
- Take Oobleck outside and hose it off (cornstarch is biodegradable and excellent for your plants!) 🙂
If Oobleck gets on anything, the best thing you can do is let it air dry.
Once Oobleck dries, it becomes powdery.
You (or your kiddos!) can vacuum or sweep that right up.
How to Store Oobleck Slime?
The best way to store Oobleck is in an airtight container in the fridge.
You may need to remix the cornstarch and water to get it back to the right consistency.
Now you have an easy Oobleck recipe you can whip up in under 10 minutes.
Put the dough and your kiddo on a versatile playmat and they’ll be all set for hours of play!
Want another new diy activity your child will love? See this super fun Spring Sensory Bottle that’ll dazzle the eyes and ears!
So, did your kids have fun playing with the Oobleck? Let me know your experiences in the comments!
About the Author
Kris McCormick is a boy mama, wife, and blogger. Since becoming a mom six years ago, she’s been researching the best advice, resources, and baby gear from small businesses to make pregnancy and child-raising easier for all parents. You can read more about Kris here.