Oobleck Goopy Goop

Have you read my post on Kinetic Sand yet? Well, I wrote in that post that I will be putting together a tip for all of you about OOBLECK and how to make it, so that your kids can have tons of fun playing with it. So here it is, enjoy…

Oobleck has a similar (but definitely not the same), texture as kinetic sand. Oobleck or Goopy Goop (as it is also known), is another sensory play wonder that my kids love to experiment and get creative with. 

To read more about the benefits of sensory play, read my post on Kinetic Sand.

Oobleck is a fascinating science experiment for kids of all ages (adults too). It was originally the name given to a type of sticky slimey liquid in a 1949 Dr. Seuss children’s book (Bartholomew and the Oobleck). This liquid fell from the sky as a result of the king becoming bored with normal weather and it was capable of gumming up a whole kingdom.

The Oobleck that we make is really incredible and can behave like a solid or a liquid depending on how much pressure you apply to it. If you try to grab some in your hand it will form a solid ball in your palm until you release the pressure. Then, it will flow out slowly between your fingers. Totally amazing!

Here is what you need to make it:

• Cornstarch or Arrowroot powder

• Water

• Flat baking pans or similar containers

• Measuring cups

• Mixing spoon

• Newspaper or cloth for covering tables or the floor

• Food colouring or tempera paint

This is how you make this fun gloop:

• Place one and a half cups of cornstarch in a pan

• Add one cup of water, and stir well

• Add more water or cornstarch until you get a mixture that ‘tears apart’ when you quickly scrape your finger through it and then ‘melts or slides’ back together again

• If you want to color your Oobleck, add some tempera paint or food colouring. Food colouring does tend to stain though, especially if you have a spill while preparing your Oobleck. And hands are also left wonderfully colourful!

A note of warning: Oobleck is not a solution (a mixture where one of the substances dissolves in the other) but rather a suspension (an example of a suspension is a mixture of water and sand: when mixed up, the sand will disperse throughout the water but if left alone, the sand will settle to the bottom). The cornstarch does not dissolve in the water like salt or sugar would but instead, the tiny starch particles ‘hang’ in the liquid. If you let it sit long enough, the cornstarch will settle to the bottom leaving a layer of clear water on the top.

I have heard that it is very important not to pour Oobleck down the drain. If the suspension separates in your drain pipes, you will be left with a hard clump of cornstarch that will block the drain! The best way to get rid of your Oobleck is to simply put it in your rubbish bin / trash can.

Here are some creative fun things that your kids can do with Oobleck:

• Firstly let them just place their hands into the Oobleck and start squeezing, squishing, scooping and pinching it. Enjoying the amazing texture and the way it reacts.
• Then show them how to make a ball by moving it around quickly in the palms of their hands. Once they stop applying pressure to the mixture, it will flow out of their hands like a liquid.
• Next fill a flat plate with a thick layer of Oobleck and then slap the surface with your open hand. Because of the force applied, the liquid will all stay in the plate and not splatter up. Try the same experiment with water and compare the results!
• They can drive toy cars through it (the cars and any other plastic toys wash off very easily), pour it through a strainer or a dish with holes in it, send it down a marble run or half pipe, add dish-washing liquid to it for a soapy experience… Use your imagination and go wild!

This is one that we have not tried yet but it sounds fantastic: 

If you have a lot of cornstarch and a small pool or shell, you can supersize this experiment and actually walk or run on the surface without sinking! But, once you stop moving, you will begin slowly sinking into the liquid.

A few ideas that I will be trying soon:

• to freeze Oobleck,
• paint with it on sidewalks and
• to make it dance on a speaker covered with plastic.

When you are finished having fun with your Oobleck, just pour or scrape it into a plastic container, put a lid on it and place it in your fridge to store it for another wonderful time of creativity. Mine lasted about two months before it started going mouldy.

Have I left any ideas out? Let me know in the comments area below. Thanks!