Oobleck is one of our go-to favorite sensory activities. It's easy to set up, super fun and is even edible if you make it with food coloring, so is nice and toddler friendly. Our little guy has been playing with it since he was eight months old, so he's an old pro by now. Making oobleck is pretty easy, mostly because the recipe is super forgiving.
To make Oobleck, you'll need:
Dump whatever amount of cornstarch you'd like to use into a container. If you'd like to add color, add several drops of food coloring. We used McCormick's Neon Food Coloring because the neon green is super cool. There is some slight discoloration on my kids' hands for a washing or two after using it, so if that might bother you, oobleck is just as fun without color. Next, add water a small amount at a time. I usually add about 1/4 cup at a time and mix as I go. At first it will be very hard and crumbly, but as soon as you've added enough water that it's moveable, you're probably good.
I like to check to see if I've added enough water by drizzling a handful. It should look like this: funny wiggly ribbons of oobleck.
You can also pat your hand on it really quickly and it should behave as a solid and be very firm. But if you slowly stick your fingers in, it should feel more like a liquid.
It's also really fun to drizzle on your hand. Despite appearances, it is very easy to clean up because it sticks together and wipes off easily.
It's endlessly mesmerizing to my kids ... and to me. I can never resist joining in on the fun with this one!