This morning we did one of our favorite summer activities that we started last year~making OOBLECK! T & I actually learned to make it in Vacation Bible School last summer and it quickly became a favorite that we have since modified in other ways as well. First we read Bartholomew and the OOBLECK by Dr. Seuss to set the mood. It actually is a nice, quirky little story with a good moral to it. If read with enough expression it captures L’s attention just enough too.
Then we head outside with:
1 medium sized bowl
2 wooden spoons
2 cups cornstarch
1 cup water
green food coloring
(The recipe calls for 2 parts cornstarch to 1 part water but I’ve found that 2 cups cornstarch to 1 cup water makes just the right amount for my two to play with for a while.)
We mix it all together to get a bowl full of OOBLECK!
There are lots of science lessons that could go along with this activity and some can be found right here but given the young age of these two we just play, explore, ask questions and investigate. You really have to make it to understand how amazing this stuff it. It will solidify if you keep it moving and try to roll it around in your hand but as soon as you stop moving it, it will “melt” back into a liquid form. It “melts” so quickly that I had a hard time coordinating in order to take a picture of it in solid form! My kids absolutely LOVE this stuff and as you can see, I can’t help but get a hand in there too. It really is fun!
“Oobleck is often referred to as a ‘non-Newtonian’ substance because it does not behave as Newton’s Third Law of Motion states; for every action, there is an equal and opposite reaction. Applying this principle, you would expect Oobleck to ‘splash’ when you ‘smack’ it with your hand. (Smacking is the action, splashing is the reaction.) However, when you try this out, Oobleck does not splash, in fact, it becomes a solid substance for a few moments.”
The other great thing about this stuff is the cleanup. All we do is let it dry on our hands and it turns into a powdery coating that can be mostly rubbed and clapped off. There is only a little residue left to then easily rinse away.

We also like to water this recipe down to make sidewalk paint. I use about 1 part cornstarch to 1 part water and throw in some food coloring to make what is basically a liquid sidewalk chalk. It paints on like a really watery paint but dries like sidewalk chalk. If you mix it too thin and it doesn’t dry “chalky” enough, just add a little more cornstarch, but be careful not to add too much at a time or you’ll end up with more OOBLECK!


  1. //

    Thanks for sharing. I will for sure do this.

  2. //

    What fun!!! Lots of tricks to being a Mommy.
    Love Grandma

  3. //

    we cer engr’s call that dilatant. think of running fast on wet sand, then dribbling it through your fingers for a sand castle. Same thing.

  4. //

    Now how have I never heard of THAT book by Dr. Seuss? Or that crazy substance?? We’re going to have to try THAT one! They will all love it, but {O} is especially very tactile, and always has been. Awesome. Grabbing that receipe right now!

  5. //

    I look forward to trying that with my kids! I’m not sure I’ll be brave enough to put my hands in though, we’ll see! =)

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