Wondering how to make oobleck? Our oobleck recipe is the perfect way to explore science and enjoy a classic Dr. Seuss book, Bartholomew and the Oobleck, all in one!  Just 2 ingredients, cornstarch and water, and the right oobleck ratio makes for tons of fun oobleck play.

How To Make Oobleck

How do you make oobleck recipe for bartholomew and the oobleck Seuss Science

What Is Oobleck?

But first, what is oobleck?  Our oobleck is inspired by the green gooey substance in Dr Seuss Bartholomew and the Oobleck book.  Oobleck is made of just 2 simple kitchen ingredients, cornstarch and water.

Can you imagine oobleck falling from the sky as happens in Bartholomew and the Oobleck?  What would it feel like to have goo all over you? Would you like that or not?

Oobleck Ingredients

Oobleck is a great example of a mixture!  A mixture is a material made up of two or more substances combined together to form a new material and that can be separated again. 

The ingredients for oobleck are cornstarch and water. Do you think your oobleck mixture could be separated into cornflour and water again?  How?

Try leaving a tray of oobleck out for a few days.  What happens to the oobleck?  Where do you think the water has gone?

Is Oobleck A Solid Or A Liquid?

What state of matter is oobleck? Here we are combining a liquid and a solid, but the mixture doesn’t become one or the other. 

A solid has its own shape whereas a liquid will take the shape of the container it is put into.  Oobleck is a bit of both!

That’s why oobleck is called a non-Newtonian fluid.  This means it is neither a liquid nor a solid but has properties of both! 

You can pick up a clump of the substance like a solid and then watch it ooze back into the bowl like a liquid.  Touch the surface lightly and it will feel firm and solid. If you apply more pressure,  your fingers will sink into it like a liquid.

Is oobleck a solid?

Oobleck being shown as a solid

Or is oobleck a liquid?

Oobleck being shown as a liquid

Did you know that cornstarch is a polymer? Polymers have long chains that make them up (like the glue used in slime). When these chains get all tangled up with one another, they create more of a solid!

If you like making oobleck, why not try making slime with our favorite slime recipes!

Bartholomew and the Oobleck Science Activity for Dr. Seuss

Oobleck Recipe


  • 2 cups cornstarch
  • 1 cup water
  • Food Coloring (optional)
  • Small Plastic Figurines or Items (optional)
  • Baking Dish, Spoon
  • Book: Bartholomew and the Oobleck by Dr. Seuss

How To Make Oobleck

Oobleck is a combination of cornstarch and water. You will want to keep additional cornstarch on hand if you need to thicken the mixture. Generally, the oobleck recipe is a ratio of 1:2, so one cup of water and two cups of cornstarch.

STEP 1:  In your bowl or baking dish, add the cornstarch. You can start mixing the oobleck in a bowl and then transfer it to a baking dish if you prefer.

adding cornstarch to bowl on tray

STEP 2:  If you want to give your oobleck a color such as green, add food coloring to your water first.

Remember that you have a whole lot of white cornstarch so you will need a good amount of food coloring if you want a more vibrant color.

adding green water to cornstarch

STEP 3:  You can start mixing up your oobleck with a spoon, but I guarantee you are going to need to get your hands in there at some point during the mixing process.

Using a spoon to mix cornstarch and water

Grab your free Dr. Seuss STEM Activities Pack here!

Oobleck Ratio

There is a gray area for the right oobleck consistency. First, you don’t want it to be very crumbly, but you also don’t want it to be very soupy either.

If you have a reluctant kiddo, hand them a spoon to start. Let them warm up to the idea of this squishy substance. Never force them to touch it though.

The perfect oobleck recipe ratio is when you can pick up a clump in your hand, form it into a ball of sorts, and then watch it flow like a liquid back into the pan or bowl.

Once you have your oobleck mixed to the desired consistency, you can add your accessories and play!

Plastic figures being drizzled with oobleck for Bartholomew and the Oobleck

Do An Oobleck Experiment

You can turn this oobleck recipe into a fun oobleck experiment. It would make an easy science fair project!

How? Easy, change the ratio of water to cornstarch and you have a viscosity experiment. Viscosity is the physical property of fluids and how thick or thin they are, including how they flow.

What happens when you add more cornstarch?  Does the oobleck become thicker or thinner? What happens when you add more water?  Does it flow faster or slower?

Can You Make Oobleck Without Cornstarch?

You could even try an oobleck recipe with flour, powder, or baking soda instead of cornstarch. Compare the similarities and differences.

We tried an oobleck experiment of our own using cornstarch and glue.  Find out what happened —> Oobleck Slime

Bartholomew and the Oobleck Science Activity for Dr. Seuss

More Fun Oobleck Recipe Ideas

Once you know how to make oobleck, there are so many fun variations you can try. Why not…

Make oobleck in a rainbow of colors.

Create a treasure hunt oobleck for St Patrick’s Day.

Add some candy hearts to a Valentine’s Day oobleck.

Make applesauce oobleck for Fall.

What about a spooky Halloween oobleck recipe!

Also check out our easy and fun sensory play recipes!


Click on the link or on the image below for more fun Dr Seuss activities.

Easy to set up Dr. Seuss science and STEM activities for Kids