Ooblek comes from a Dr. Seuss book published in 1949, which I confess I’ve never read! But you don’t need to know the story to have fun with this mysterious substance – part liquid, part solid. They key lies in achieving the right ratio of cornstarch to water.
There are two ways I’ve found to do this: being precise, or just winging it.
If you want to do the former, enlist your child to help you pour 1/2 cup water into a large container (a disposable aluminum pan works perfectly). Add 1 cup cornstarch, then use your hands or a spoon to stir the mixture.
Travis prefers this method, because he enjoys measuring out recipes. Once we had our ooblek, he insisted on adding food coloring, so we made it green. This turned out to make the perfect neon green ooze.
For the “winging it” method, I dumped cornstarch into a tray first, and then had Travis help me add water until the ratio seemed right. This can be a fun way for kids to tinker with figuring out how and why the mixture works; we discussed solid versus liquid as two states of matter while we played, and how ooblek is a little bit of both.
Eventually Travis decided that this batch should be purple, but you can have fun with it plain white, of course!
Kids will likely find all sorts of ways to play with ooblek, including adding objects to the pan, pressing on it, stirring it – and of course dipping in their hands.
Have fun squeezing it and seeing what happens!