Technically, oobleck is a non-Newtonian fluid. If that sounds like total gibberish, hang in there for a moment. A non-Newtonian fluid is a fancy name for a substance that isn't a liquid or solid. It takes on properties of both, depending on how much pressure is applied to it. This describes oobleck perfectly: a fun, mysterious substance that sometimes acts like a liquid and others, a solid. Oobleck first gained fame in the 1949 Dr. Seuss book Bartholomew and the Oobleck as a mystical substance that comes from the sky. Today, making your own oobleck is incredibly simple to do.
Making oobleck requires just two ingredients: cornstarch and water. You can also add food coloring if you wish, but it isn't required. Plain white oobleck can be just as fun as colored oobleck! The exact measurements for the cornstarch and water depend on how much oobleck you want to make. The general rule of thumb is two parts cornstarch to one part water, so a good amount to start with is two cups of cornstarch and one cup of water.
Add your cornstarch to a bowl, then slowly add the water. Remember to maintain the 2:1 ratio regardless of how much oobleck you're making. For example, if you want to make double the amount of a standard batch, use four cups of cornstarch and two cups of water. For a small half batch, use one cup of cornstarch and half a cup of water. Use your hands to mix the oobleck until smooth.
Although it's not required, most people choose to color their oobleck. Using food coloring, add several drops to the mixture and stir until it's thoroughly combined. Gel food dye is recommended because it's more pigmented, so you can use less. There are no rules here, so make the colors as light or bright as you want or use multiple colors to create custom shades. The food coloring may stain kitchen utensils, so it's a good idea to use a wooden skewer.
If you're new to making oobleck, it can be tricky knowing when the consistency is just right. Oobleck should form into a ball when you grab it in your hand but go back to liquid form once it's released. As you're stirring, test the mixture by running a finger down the middle of it. It should separate, creating a part where your finger was, but then quickly come back together. Add more cornstarch if it seems too runny or a few drops of water if it's too firm.
Now for the fun part – you get to play with your oobleck! Children and adults alike will enjoy experimenting with it. It's interesting to watch how the oobleck changes properties from a liquid to a solid depending on how it's handled. Form it into a ball, pull it apart, and watch how it melts in your hands. Consider playing with it outside or covering a table with a disposable tablecloth or newspapers to make clean-up easy.
Playing with oobleck is not only fun, but it can also be educational. It's a great way to teach kids about the different properties of liquids and solids. Put the oobleck into a colander or a fruit container that has holes on the bottom, such as a strawberry or blueberry package. Watch as the oobleck drips, but notice how it's clearly different from a liquid. Fascinating!
Dipping different objects into your oobleck is another great science experiment that's both fun and educational. Use items of different sizes, textures, and weights to see how the oobleck reacts to and with them. Does the oobleck stick to them, drip right off, or some combination of the two? Remember, this is probably an activity best done outside to minimize the mess.
You can divide your oobleck batch into a few smaller bowls and make different colors with each of them. Then, experiment making different works of art with the colors. Put them side by side and watch how they interact with each other. Try using a spoon or skewer to drizzle one color over another and make shapes or letters. Does it spread out or keep its shape? Consider doing this in a pie tin or on a cookie sheet.
Playing with oobleck can be a pretty messy experience. One way to make it easier to clean up is to leave it and let it dry. While that may sound counterintuitive, it really works! Once it dries, it becomes the consistency of cornstarch, and you can wipe, sweep, or vacuum it right up. To get oobleck off of your hands or clothes, use plain warm water. Thankfully, it usually comes right off!
Oobleck isn't something that will keep well for a long period of time, so once you're finished enjoying it, it should be tossed out. It may be tempting to put it down your garbage disposal but don't. The sticky substance acts as a glue inside plumbing pipes and can cause a major blockage. Instead, simply toss it in the trash can.