Let’s Make Oobleck - Fun at-home activities for Kids.

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Let’s Make Oobleck!

Make oobleck from cornstarch and water, test its solid-liquid behavior, carefully squeeze it, and explore non-Newtonian fluids safely at home.

Table of contents

Step-by-step guide to make oobleck

What you need

Cornstarch, water, large bowl, measuring cup, spoon, tray or plastic mat, food coloring (optional), zip-top bag or sealable container, towel, adult supervision required

Step 1

Ask an adult to help you start the activity.

Step 2

Place the tray or plastic mat on a flat table to protect the surface.

Step 3

Scoop 2 cups of cornstarch into the large bowl.

Step 4

Measure 1 cup of water in the measuring cup.

Step 5

Pour the water slowly into the cornstarch in the bowl.

Step 6

Stir the mixture slowly with the spoon until it looks mostly combined.

Step 7

If you want color add a few drops of food coloring and stir until the color is even.

Step 8

Tap the surface quickly with one finger to feel the mixture act like a solid.

Step 9

Press your finger in slowly to feel the mixture act like a liquid.

Step 10

Squeeze a handful gently and watch it hold together while you squeeze and fall apart when you stop.

Step 11

Scoop leftover oobleck into a zip-top bag or sealable container and throw it in the trash (do not pour it down the sink).

Step 12

Wash your hands and the tray with soap and water and dry with the towel.

Step 13

Share a photo or description of your finished oobleck experiment on DIY.org.

Help!?

What can I use if I can't find cornstarch?

If you can't find cornstarch (sometimes labeled corn flour) try tapioca starch or arrowroot as a substitute, but expect a slightly different oobleck texture when you pour and squeeze the mixture.

My oobleck is too runny or too dry—how do I fix it?

If the mixture in the large bowl is too runny, add cornstarch a tablespoon at a time and stir with the spoon, and if it's too dry add water a teaspoon at a time until tapping feels solid and pressing flows.

How can I adapt this activity for younger or older kids?

For toddlers, make a half batch on the tray and have an adult pour the water and demonstrate tapping and squeezing, while older kids can vary the 2 cups cornstarch-to-1 cup water ratio, record how the mixture behaves, and test different amounts.

How can we make the oobleck activity more creative or educational?

Add a few drops of food coloring for marbled effects, mix in glitter or small plastic toys in the tray for a treasure-hunt challenge, or run experiments by changing cornstarch amounts and photographing results to share on DIY.org.

Watch videos on how to make oobleck

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OOBLECK FOR KIDS | Non-newtonian Fluid | How to Make Oobleck |

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Facts about non-Newtonian fluids

🧪 Oobleck is a non-Newtonian fluid — it pours like a liquid but acts like a solid when you hit or squeeze it.

📏 A common kid-friendly recipe uses about 2 parts cornstarch to 1 part water by volume (adjust until it feels right).

🤸 Move quickly and you can run across a deep pool of oobleck because it stiffens under sudden force.

📚 The name “oobleck” comes from Dr. Seuss’s 1949 book "Bartholomew and the Oobleck."

🛡️ Scientists study shear-thickening fluids like oobleck for uses such as flexible body armor and impact protection.

How do you make oobleck and test its solid-liquid behavior at home?

To make oobleck, mix about 2 parts cornstarch to 1 part water in a bowl. Stir slowly, then knead with your hands until it pours like a liquid but feels solid when squeezed. Test behavior by slowly dipping a finger, then clapping or squeezing to see it act like a solid. Let it sit to turn back to liquid. Always supervise children, avoid putting oobleck in mouths, and cover surfaces to contain the mess.

What materials do I need for making oobleck?

You need plain cornstarch, clean water, a mixing bowl, and a spoon or hands for stirring. Add optional items: food coloring, a shallow tray, measuring cups, small toys for experiments, and paper towels for cleanup. Have a waterproof table cover and a trash bag ready. Avoid drains: dispose dried oobleck in the trash, not down the sink. Adult supervision is recommended for younger children.

What ages is making oobleck suitable for?

Oobleck is great for sensory play; best for ages 3 and up with close adult supervision. Preschoolers (3–5) enjoy the squishy feel with help, while elementary children (6–10) can measure ratios and run experiments independently. Toddlers under 3 may put it in their mouths, so avoid unsupervised play. Adjust complexity and safety steps by age, and always supervise messy science activities.

What safety tips and cleanup steps should I know for oobleck?

Keep oobleck out of mouths and eyes and supervise children closely. Protect surfaces with plastic or a tray; wear clothes that can get messy. If it sticks to skin, rinse with water and rub gently—cornstarch washes off easily. Let leftover oobleck dry, then crumble and throw it in the trash. Never pour large amounts down the sink. For variations, add food coloring or mix in small toys for discovery play.

Ready to create?