Oobleck – The Corn Starch And Water Experiment
This may just be the easiest, messiest, and most fun science activity I know. It is a classic, and I have gotten several requests recently to post directions. You should know that if you try this activity and you are not smiling and messy with corn starch goo at the end, then you are definitely doing something wrong. Also keep in mind that this is not just about fun, there is some pretty amazing science going on here.
You will need:
- Cornstarch (a 16 oz. box is good for every 2-3 participants – but more is always better)
- Water
- Food coloring (we always say it’s optional, but it does make it more fun – don’t use too much or you could end up with colored hands…and clothes…and curtains)
- A large bowl
- A camera – you’re probably going to want to take pictures.
Everyone should roll up their sleeves and prepare for some gooey fun.
- This is easy. Pour the cornstarch into the bowl. Don’t rush to add water – take time to feel the cornstarch. Cornstarch does not feel like any other powder. It has a texture that can be compared to that of whipped cream. The grains of cornstarch are so small that they will fill into grooves of your fingerprints and make the prints stand out.
- After you’ve taken-in the feel of the powder, it is time to add water. (You should add the food coloring to your water before adding it to the powder.) There are no exact formulas regarding how much water to add, but it will end up being about 1/2 cup (120 ml) of water per cup (235 ml) of cornstarch. The secret is to add the water slowly and mix as you add it. Don’t be shy here – dig in with your hands and really mix it up. This is usually when you notice that this is not your average liquid. Add enough water so that the mixture slowly flows on its own when mixed. The best test is to reach in and grab a handful of the mixture and see if you can roll it into a ball between your hands – if you stop rolling it and it “melts” between your fingers – success!
We’ll get the the science soon, for now just dig in and explore. Notice that the goo does not splash (or even move) if you hit it quickly. Squeeze it hard and see what happens. How long can you get the strands of goo to drip? What happens if you let the goo sit on the table for a minute and then try to pick it up? How does it feel? Hows does it move? Try bouncing a ball on the surface of the cornstarch. You get the idea – explore!
30 minutes later…
So now goo is everywhere and you’re thinking you should probably start cleaning. Actual clean up of the goo is a snap. A bucket of warm water will quickly get it off your hands. It will brush off of clothes when it dries, and it is easily cleaned off surfaces with a wet rag. Important: Make sure you do not dump the goo down the drain – it can get caught in the drain trap and take the joy out of your day of science. Dump it in the trash, or even mix it into soil in the garden.
Cornstarch grains under the microscope
Now for the science…
Our cornstarch goo (sometimes referred to as “oobleck” from the Dr. Suess book) is what scientists call a “Non-Newtonian” liquid. Basically, Sir Issac Newton stated individual liquids flow at consistent, predictable rates. As you likely discovered, cornstarch goo does NOT follow those rules – it can act almost like a solid, and them flow like a liquid. Technically speaking, the goo is a SUSPENSION, meaning that the grains of starch are not dissolved, they are just suspended and spread out in the water. If you let the goo sit for an while, the cornstarch would settle to the bottom of the bowl.
So why does this concoction act the way it does? Most of it has to do with pressure. The size, shape, and makeup of the cornstarch grains causes the cornstarch to “lock-up” and hold its shape when pressure is applied to it. People have filled small pools with oobleck and they are able to walk across the surface of it (as long as they move quickly.) As soon as they stop walking, they begin to sink.
I hope you get to try this out. Let us know how your day with non-newtonian liquids went. Comment here, or, even better, send us pictures to comment@sciencebob.com . Have fun exploring!
-Science Bob
I’ve made this many times and every time it gets better! I love how you add water and it almost disappears making it easy to clean up, and it feels awesome having a plasma-like goo-substance act like a liquid, then a solid. My friends grin at me when they see that I’ve made Corn starch + water- they love it!
that is what i am totally doing for my science fair project thanks so much i will be smiling and havig so much fun lol lol lol lol lol lol lol
i love it i will make for my scince project for the LGSM
me too (:
This stuff is soooooooooo awesome!!!!!!!!!! <3333
this is awesome!!!!!!!!!!!!!!!!!!
:) :O
:O
This so koo!!
this is a good experiment for a science fair and is really fun to play with. it is able to be identified as a soquid. if you poke it fast you won’t get your finger in but if you poke it slow it is liquid and if you hold it it is liquid
Does this come out as slime? HOw does it work?>?>?>?
im doin this for my science project n is awsome.. is funn to play wiht =)
this is so cool man i got crazy over this experiment
Cornstarch and Water is so cool . WOW! i m doing this for my science project
this is awsome
I’m doing this for my science project. Its funnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn
very messy-lol but i like messy. this look so awesome!!!!!!!!!!!!!!!! and really funnnnnnnnnn
XD
its too nice.my sister also done this
cool
that is so cool i have made it before it is so fun to make
its gooooooooooooooooooooooy!!!! i love it!! its so much fun i could play with this stuff all day
tried rolling it into a ball and threw it against a wall. it shattered and then all the little pieces melted. it was impossible if you didnt have enough starch tho.
Sciencebob is amazing program. It taught me all the amazing stuff you can do and have fun with science. Sciencebob’ s videos are intersting, funny, and cool. Keep up the good work, Sciencebob!
omg oobleck is so cool you have to try it! if you doun’t you will be so left out! it’s so messy science rules! o wait ther are no rules in science! but it still rocks! thers no reason not to smile on hollowean! when you have that jar of oobleck with your cute costume! so try it it is awsome! and trust the pro is is so cool! just like me!
I dont know what to say it is just so amazing and stuff i hope you come with mind blowing experiment till then signing off
yours sincerely,
great-boy!!!!!!!!!!!!!!!!!!!!!
thanks for the tip zawe
Im doin dis one for my project because it look so fun
This is so cool
hey guyes im doing a sience fair project but our end result has to be numbers any ideas
I cant wait to try this out
this is so fun i did it for 6th grade and we had a blast we would run and jump really fast and it was just like cement but when you would punch it really slow your hand would get all slimy lol it was fun i love it and i still enjoy doing it even though im in 7th grade
Thanks for the advise you helped me !
well OMG, we did this in class one day and i still dont understand is it a liquid or is it a solid?
i did this in school and it was the best thing ever it felt so cool now i am doing an essay on it!!!!!!! LOL !!!!!!!!!!
I added to much water and it took one whole night to form.
This looks fun and it looks cool., i might do this on my science fair project… i hope it gives me an A+!
LOl , So i’m just gonna do this instead of making a tornado in a bottle . Haha ! 
I will be using this in college for my business professional presentation. my college class mates will be treated as 4 years olds since that is my concentration.
I haven’t tried it yet so im hoping it goes well
i did this science project for the science fair at my school with my friend and we got a good grade
this was the best science experiment ever!
we all got so messy and gooed up we could barely walk!
thanx 2 mr.Williams!!!
This stuff is sooooooooooo fun! it cleans up easily to
This activity was very fun for my kids! One of them does not particularly like school work (they are home-schooled by tutors) so his main tutor did this experiment and he suddenly started liking science! This is a great activity in and out of school!
im doing this for 7th grade science fair
Hey,
Love this experiment. I was just curious, are there other forms of suspension other than cornstarch and water?
what if you microwaved it for, say, a minute or two?
How can you use this for science fair if it’s not measurable
greatt project!!
OMG!!! I LOVE OOBLECK ITS SOOO AWSOME AND FUN TO PLAY WITH. IM DOING THIS FOR EVERY SCIENCE PROJECT!! HAHAHA
im going to do oobleck with my friend ada in the science fair !!!!!!!!!!!! it will be cool
Why does it do that though, I need an answer please!
What if you mixed liquid nitrogen or dry ice in with oobleck…?
I won 1st place in the science fair with this !!!!
this is crazy… but if you put it on a speaker it actually bounces!!!!!