Did you know you can walk on oobleck? My children participated in a fun race called Mini Mudder a couple of years ago. One of the obstacles was a huge tray of cornflour oobleck, which everyone loved, so we thought we'd try to create a smaller version in our garden. Our giant oobleck tray was SO much fun. We had it out in the garden for ages as it dried in the sun each day, so we just had to add extra water to make it fresh and slimy to use again.
What is oobleck?
Oobleck is a mixture of cornflour and water. The funny thing about oobleck is that if you scrunch it up in your hand, it feels solid, but if you unclench your hand and let it run through your fingers, it flows like a liquid. We call oobleck a non – Newtonian fluid as it doesn’t flow like liquids normally do.
How to make a giant oobleck tray
To make our giant oobleck tray, I poured about 1 kg of cornflour into a large black tray and slowly added water until the consistency was wet but solid when squeezed. If you don't want to go large, find out how to make oobleck on a smaller scale.
How does oobleck work?
Cornflour oobleck is made up of molecules arranged in long chains. When the chains are stretched, the liquid will flow, but when you force them together, they stick together to form a solid.
Giant Oobleck Tray
The photos show how much fun we had. There is a lot of cornflour, but I left the tray to try in the sun and then scooped up the dry powder, which allowed us to use it over and over again.
What can you do with oobleck?
We tried walking, running and even cartwheeling over the oobleck. The children found that if they ran quickly over the surface, their feet stayed dry, but if they walked slowly, they started to sink!
Once the big children had finished playing for the day, we added some plastic fish and turned it into an ocean play tray for the littlest member of the family. He loved it!
If you enjoyed this activity, you might also like our no borax slime recipes!
The Play Based Mom has some amazing looking rainbow oobleck too!
Last Updated on May 14, 2024 by Emma Vanstone
Olivia says
I forgot all about this! I never knew it had a name but I used to make it all the time as a kid. My children would absolutely love this I can't wait for summer now!
Lois Wickstrom says
Cartwheeling! I love it! Thank you!
Shantris Jensen says
This looks like so much fun! How do you get rid of the oobleck when you are finished?
I want to do this at my child’s school and they won’t approve it unless I have a way to dispose of it.
Emma Vanstone says
I usually leave it to dry out and the throw it away.