Q&A for How to Make Oobleck

Oobleck is a term taken from the Dr. Seuss book Bartholomew and the Oobleck, in which the character of the Oobleck is a green, blobby, oozy substance of similar characteristics to this non-toxic, inexpensive non-Newtonian fluid.

When disposing of Oobleck, do not try washing it down the sink or flushing it down the toilet––Oobleck contains ingredients that can clog up drains badly. Instead, wrap the Oobleck in newspaper or junk mail, then toss it into the trash can for regular disposal.

Oobleck usually requires cornflour and water, as outlined in the steps above. Possible additions include glitter, food coloring or other safe coloring (since Oobleck can end up in a child's mouth). For other types of Oobleck, with different ingredients, see How to Make Oobleck without Cornstarch .

Flour (standard wheat flour) will not make Oobleck. Once combined with water, it will create a paste instead, which is how a simple homemade glue is actually made. The usual ingredient is cornflour but you can also use arrowroot powder or tapioca powder instead, see: How to Make Oobleck without Cornstarch .

It is not possible make cornstarch at home. The method for making cornstarch is complex and requires industrial refining equipment and processes. A similar product can be made at home using potato starch but it’s not cornstarch.

You can use cornflour or baby power.

Yes, as long as it's tied or sealed. This makes for a great stress ball if you don't add air.

Yes. An airtight container will keep air away from your oobleck and keep it from drying out.

Yes, but make sure that you always use the same ratio: 2 parts cornstarch and 1 part water.

Try adding a little bit more cornstarch and using less water.

Oobleck is a lesson in composite materials: how different parts of a mixture contribute new properties to the whole, like a metal alloy or laminated glass. Oobleck also acts as a non-Newtonian fluid (like a solid) under mechanical stress due to the proprieties cornstarch confers to the mixture.

Yes. The texture might be a little different, but cornflour will work in essentially the same way as cornstarch.

No. Instead of turning into oobleck, flour mixed with water will turn into dough.

As explained in the first step, 1 cup. Or, you could start with about half as much water as cornstarch (2 cups cornstarch, 1 cup water). Then add a little more cornstarch for a thicker consistency or add a little more water for a thinner consistency. Both consistencies still work well as long as you don't overdo it.

Oobleck (and all non-Newtonian fluids) behave like solids when you apply enough force. The weight of the Oobleck on top is enough to make it feel solid at the bottom. This can help to show kids that weight and force are closely related.

No, oobleck does not need to be refrigerated.

Oobleck is what's known as a non-Newtonian fluid. Basically, this means that it acts like a solid when struck forcefully, but acts like a liquid when touched gently.

Yes, it should not be able to let your hand pass if you hit it, and it should run through your fingers like thick fluid when you very slowly squeeze it.

The bowl needs to be large enough to hold at least three cups.

Use 1 cup of water for every 2 cups of cornstarch. You can use the same cup to measure the water and the cornstarch.

Its hard to explain but, oobleck is a liquid-solid mix. Therefore, applying a lot of pressure will cause it to solidify/harden, and releasing the pressure will cause it to liquefy.

Yes, just make sure it is a two to one ratio, with two parts cornstarch and one part water.

It's a liquid that when you apply a lot of pressure to said liquid, at once it acts as a solid but if you slowly move the liquid, it acts as a liquid.

You can just buy it at your local supermarket. It is usually used for baking, so it may be in the baking section. Food coloring is going to change the color of your Oobleck, so you can get it in a variety of colors.

Oobleck is very very messy and you wouldn't want to take it to school open. Try making a DIY stress ball with a balloon and your oobleck. There are lots of tutorials on YouTube!

Yes, it is, but any kid who ate it would only make that mistake once.

No, it will not.

Yes, there are some YouTube videos on it. It may not be exactly what you are going for, but it could work.

Use a large amount of the ingredients listed and mix until it is the right consistency. If it's too runny, add more corn starch. If it's too solid, add more water.

Yes, because it's really just cornstarch and water, but it probably won't taste very good.