Homemade Goop is one of the best things I’ve learned how to make as a parent, and today I’m going to share this big secret on how to make goop aka how to make oobleck.

It’s the easiest recipe, and full of so much fun for small children.

Have you tried it? The recipe is simple and children are riveted by the magic of this weird substance.

How to make Goop :: Tinkerlab.com

Fun History of Goop

Goop, better known as Oobleck (named for a slime in Dr. Seuss’ book Bartholomew and the Oobleck ) is a fun material to play with: At one moment it’s a solid, and at the next it’s a liquid…it’s unbelievably silly to play with, and I’ve witnessed adults get lost in the strange sensation of its texture. For my science friends out there, this is a dilatant material, which is one that changes its properties in reaction to external stimuli. We don’t have the Dr. Seuss book (yet!), but I imagine it would be fun to read the book in conjunction with this activity.

How to get the most out of your Goop

To get the most bang for your buck, do what I did and set up this goop-making activity up as a 3-part activity to enable your child to experience the medium in multiple ways.

How to make Goop :: Tinkerlab.com

Goop Ingredients

  • 16 oz. container of Cornstarch (this is corn flour in the U.K.)
  • Up to 1 cup of water
  • Liquid watercolors or food coloring (optional)

Goop Supplies

  • Big tub for mixing — I used an under-the-bed storage container. Contains the mess well so my child can play unencumbered by my tidy concerns
  • Spoons, little bowls, toys for playing, scooping, and filling

How to Make Goop

  1. Set up a large container such as an under-bed tub
  2. There are two ingredients in this recipe: cornstarch and water. If you don’t have the same quantities as us, the ratio is one part water and two parts cornstarch.
  3. Pour one 16 oz. container of cornstarch into the tub
  4. Pour almost all of water on the cornstarch, around 3/4 cups. Mix the water and cornstarch together with your hands. Add the rest of the water to make the consistency more liquid. Play with the ratio.
  5. Add food coloring or liquid watercolors to make it colorful.

How to make Goop :: Tinkerlab.com

How we did it…

How to Make Goop: Part 1

I placed the jar of corn starch in the tub, alongside a spoon and a couple small bowls. I expected my daughter to pour the whole tub of corn starch out, but she carefully scooped it from the container spoonful by spoonful. This took a while, as she was wholly invested in the process of measuring and then pouring. Once playing with dry corn starch ran its course…

How to make Goop :: Tinkerlab.com

How to Make Goop: Part 2

We added water. I gave her just a bit at a time, so she could enjoy the process of mixing it in. Ultimately, the cornstarch:water ratio is about 2:1.  And as we went along, we chatted about what it felt like in our hands, if it was easy/hard to stir, and what we were doing. And once she seemed to have her fill of playing with this funny material…

How to make Goop :: Tinkerlab.com

How to Make Goop: Part 3

We added a few drops of liquid watercolor to the Oobleck (food coloring would also work), which she swirled around and mixed up. She was really interested in dropping the color into the mixture, but stirring it up barely sustained her interest. After focused play with the Oobleck for the last 30 minutes, she seemed to have had enough…ready to move on to the next big thing.

If you try this (or already have it under your belt), I’d love to hear from you!

More Playdough and Sensory Recipes

The BEST Play Dough Recipe, no joke!

How to make Slime, aka Flubbery Gak

Easy Science Experiment with Vinegar and Baking Soda

Sensory Bin with Flour and Water

Explore Flour and Chalk

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  1. Oh, how funny. I almost did this with my toddler last week (there’s a nice activity involving food coloring in one of the books I own), but we did something else instead. It’s in the back of my mind, though.

    • There are so many possibilities with food coloring…I think it’s a secret staple of parenting! It’s just too bad that they still make the bottles so tiny.

  2. I haven’t done this one for a while, it is so much fun. Great idea to let her mix the ingredients! Guess what we’re doing today? hee hee

  3. fabulous! and if after mixing food coloring we add flour-dont we have playdough. oh yah, you have to heat the mixture. why not.
    I’ll try it.

    • I love where this is going…it’s an art experiment for kids and mom! Please update me on how this turns out.

  4. Yes, I have everything on hand! We are trying this morning! 😉

    • Isn’t it nice to do activities that don’t require a lot of extra stuff? Enjoy!

    • If I want to keep my child happy, messy is pretty much unavoidable these days. 🙂

  5. When we make it, we’re mixing up a huge classroom sized batch and keep it for an entire week. The challenge is that the corn starch and water tend to separate overnight and it’s a major chore to remix it in the morning, but worth it. The kids are usually crazy for it for a couple days and then the adults take over for the second half of the week!

    I’ve heard this substance described as an anti-Newtonian product because when you try to splash it, there is not “equal and opposite reaction.”

    • I’ve seen adults go ga-ga over this stuff, too. Maybe those of us who never played with this substance as kids are making up for it now 🙂 I also came across the anti-Newtonian point, and I can see why!

  6. You know, I have to say that I appreciate you having that makeshift sensory table in your home – its nice to see how often you use it, and how engaged your daughter is. more exciting than TV and other screen time for sure. This might be in our classroom sensory table soon!

    • Our little “sensory table” has been one of the best purchases! We had too many spills out of little bowls before I realized I could steal a page out of the Preschool Teachers’ Book of Tricks.

  7. I just did this today with my 20 month old. It was super messy and so much fun. Equally fun for me. What an incredible reaction. I kept telling my husband to come over and look. It’s wild how it goes from solid to liquid over and over so quickly. Anyway, thanks so much for the great directions. Love your blog! Meri

  8. i did this when i was a kid and its nice to know i wasn’t the only one. My daughter and son tried to have a goo war but they would roll it up get ready to throw it and then it would go to a liquid. i laughed and told them keep trying

  9. […] GOOP: (1 box Cornstarch, <1c. water, food coloring) – NOTE: This works best if mixed in a rubbermaid bin and also helps keep the mess contained. DO NOT DO THIS ACTIVITY ON CARPET! In bin, dump Cornstarch, add ¾ cup of water, mix with clean hands and add small amounts of water as necessary to get desired consistency.https://tinkerlab.com/goopy-cornstarch/ […]

  10. I made this with my daughter during quarantine and had fun writing on it with marker, then erasing it (mixing it up) and watching the colour change. We also experimented with ‘sink or float’ and played with different shapes and weights to see what sank faster.

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