This post may contain affiliate ads at no cost to you. See my disclosures for more information.
Watermelon is, in my opinion, the fruit that says “summertime!” more than any other. Sweet, juicy watermelon is a delicious treat on a warm summer day.
And because watermelon is so juicy, it makes up a delicious batch of watermelon oobleck for some summer sensory play!
What is oobleck, you might ask? It is a non-Newtonian fluid, which is a fancy way of saying that it has properties of both a liquid and a solid. If you slowly dip your hand into it or if you try to hold it for any length of time, you will find it acts like a liquid. But if you try to squeeze it or punch it, you will find it acts like a solid.
Watermelon oobleck, then, is a great summer sensory play activity that will keep your kids engaged for quite some time!
Note: For more activities that will delight the senses, see my Sensory Play page.
Regular old oobleck is simple to make, requiring only two ingredients: corn starch and water. But to make watermelon oobleck, here are the steps we took.
First, I cut a large watermelon in half. Then my kids helped me scoop the juicy, red flesh into bowls. (Yay for fun fine motor activities!)
Once we had scraped all the watermelon flesh out of the rind, I placed it into my Vitamix blender. I blended it into a juicy liquid, and poured it back into one half of the watermelon rind.
I placed the watermelon rind full of watermelon juice in a box containing a layer of corn starch on the bottom. I took the entire box and placed it in our backyard for my kids to enjoy.
I decided to present the activity in this way to give my kids a chance to make the oobleck themselves by mixing the watermelon juice and corn starch in the box.
Indeed, they got right to work.
They mixed and poured and played. They created a beautiful, pink-colored, watermelon oobleck.
And of course they made quite a mess. (But that’s exactly why we did this activity outside!)
Note: the approximate best ratio of watermelon juice to corn starch for making watermelon oobleck is 1 part corn starch to 1.5 or 2 parts watermelon juice. If your oobleck is too dry and powdery, add more water. If it is too runny, add more corn starch.
Just keep experimenting with adding more water or corn starch until you notice a consistency that is difficult to squeeze or punch, but that will drip out of your hands when you hold it for more than a few moments. That is how you will know you have the right consistency.
More resources for summer fun and learning
More watermelon posts from Gift of Curiosity:
- Watermelon Printables Pack
- Watermelon Do-a-Dot Printables
- Books about watermelon
- Watermelon seed spitting contest
Products mentioned in this post: