Oobleck

If you're a Dr. Seuss fan then you will probably be familiar with oobleck. If not, this is a super fun and inexpensive kitchen science experiment to do with the kids! It only takes two ingredients and minimium effort. Yes it’s messy, but it's so much fun and will keep the kids entertained for ages. (Or hopefully for long enough for all the new work-from-home mom's to reply to a few emails during lockdown...)

Oobleck is a non-Newtonian Fluid  which is a fluid that does not follow Newton's law of viscosity. Basically it’s neither a liquid nor a solid, but really a suspension. It behaves like either liquid or solid, depending on the amount of pressure you apply. Squeeze the oobleck in your hand and it will feel like a solid ball, open your hand and it will fall like liquid between your fingers. Fear not parents, it’s also easy to clean!

Method

1. Pour water into an AMC 20 cm or 24 cm Dome.
2. Begin adding corn flour to the water and food colouring if using. You can stir with a spoon first but you will need to use your hand as soon as the mixture begins to thicken. Add food colouring if using.
3. You are looking for a consistency that is liquid and solid all at the same time. (Give it a squeeze and then open your hand.)
4. If you find that you have added too much cornflour, just add a little more water. Then you're ready to play!

Tips:

• First add the 1.5 cups of cornflour and add the remaining flour bit by bit as you may not need all.
• Things to do with oobleck: Make a puddle and quickly drag your fingers through it, put it into a plastic container and shake it or quickly bump it against a table. Or poke at the oobleck and then slowly let your finger sink in.