Playing in a Pool of Oobleck

Ever since book one in the Halley Harper Science Girl Extraordinaire series was published, I have tried to look for a reason to make and run across a pool of Oobleck because *SPOILER ALERT*  Halley Harper uses a pool of Oobleck to thwart the villain and save the day!

But, I always talked myself out of it – even when I wanted to have a pool of Oobleck for the book one release party. I bought the cornstarch a year ago but just kept telling myself it was going to be too messy, too hard to stir together, and too hard to get rid of!

But then I made a promise (on TV) that I would do it this summer and figured it was time to put my money where my mouth is. And I had also just moved 100 lbs of cornstarch 90 miles east to our new house and I don’t want another moving company looking at me funny when I asked them to put 100 lbs of cornstarch in their moving van!

Making an Oobleck pool was actually a lot simpler than you would think…and it was way more fun than I ever imagined! The kids thought it was amazing and I would go so far as to say… it was epic.

What you need: a 5-1/2 ft wide baby pool, two 25 lbs of cornstarch, and water

How you do it: 

• Decide on where you want the pool – I would recommend on a patio to save your grass.
• Inflate the baby pool
• Dump one 25 lb bag of cornstarch in the pool
• Add water from an outdoor water hose to make a paste (note: Oobleck is 2 parts corstarch to 1 part water)
• Add second 25 lb bag and add water while the kids mix it with their hands
• Stop adding water when you can stand on the mixture and sink but can run across the top without sinking
• You will have about 3″ of Oobleck in your 5-1/2 ft wide pool.

What’s the science: Oobleck is a Non-Newtonian fluid which means that it can be a liquid and a solid.  You can pour it and you can ball it up.  It’s sticky and it’s smooth. It all depends on the force applied to it.

I hope you attempt a pool of Oobleck for your next VBS or science party! You can also check out more of my videos on my YouTube channel here.

Have fun making your epic pool of Oobleck!