Apple Cinnamon Oobleck ⋆ Sugar, Spice and Glitter

Have you ever played with oobleck? It’s one of our favourite sensory activities for kids, and today I want to share with you a simple apple cinnamon oobleck we made to welcome fall.

If you’ve never played with oobleck, it is a really fun material that has characteristics of being both a liquid and a solid. If you apply force to oobleck, by hitting it or squeezing it, it retains solid characteristics; but if you interact with it gently, it retains liquid characteristics.

It is considered a “non-Newtonian substance,” like quicksand or silly putty, because it’s reaction to force is not constant. A Newtonian fluid (like water) will react and show viscosity proportional to the force exerted on it – for example, when you push water out of a syringe, the force exerted by the plunger is proportional and linear to how the water reacts in how quickly and strongly it pushes out of the syringe. It is constant, and predictable.

Oobleck is not predictable.

Oobleck is also known as goop, but I prefer to call it oobleck because of the Dr. Seuss Book, Bartholomew and the Oobleck. (Also, it avoids confusion with the Gwyneth Platrow platform.)

Oobleck can get pretty messy, so whenever we can, I try to play with it outside, or at least in a container. (Sometimes both!)

How to Make Apple Cinnamon Oobleck

To make apple cinnamon oobleck, I combined:

1 cup of corn starch (corn flour to my European friends)
1/2 cup to 1 cup of apple juice
1 generous tablespoon cinnamon

I started off by only combining the corn starch with 1/2 cup of the apple juice, and then adding more apple juice to reach my desired consistency.

You’re looking for a fluid that is fully uniform in texture, slipping through your fingers, but can also be formed into a ball if you squeeze a portion of it together. (A quickly melting ball.) It should bead on surfaces, rather than being runny. It’s a bit of a tricky process, I always add a bit more corn starch, a bit more juice, until I hit upon the magic formula.

I added a generous tablespoon of ground cinnamon to give the oobleck an amazing scent.

I presented the oobleck to the kids outside, with a simple set up of two pie pans (the same ones we used in our scented felt apple pie and apple pie sensory bin) and a spoon in a small plastic container.

They quickly got to work transferring the oobleck from one pie plate to another, stirring it up, stretching it, letting it slip through their fingers, and just enjoying the sensory pleasures of the cool, unpredictable substance.

The children had to think quickly and practice their creative problem solving in order to play with the oobleck. While water would make a big splash if you hit it, oobleck acts as a solid and will stop your hand from entering if you tried to hit it. If they wanted to stir or grab pieces of the oobleck, they had to suspend what they thought they knew about fluids in order to get what they wanted.

The reason oobleck reacts this way is because of those cornstarch particles. Pressure encourages them to bind together and resist force, whereas gentle play allows cornstarch particles to move out of the way – but interestingly, they do not become clumpy and stay suspended in the water, retaining a liquid appearance.