How to make oobleck without cornstarch

If you haven’t heard of oobleck, you’ve been seriously missing out! Oobleck (also called goop) is an amazingly gooey, slime-like substance that is perfect for playing around with. It’s made from just two ingredients – cornstarch and water – so it’s really easy to make.

Note that cornstarch is also called cornflour in the UK and other parts of the world 🙂 They are the same thing! Just watch out you don’t use corn flour (ground cornmeal), which is a totally different product made from corn.

Kids are usually totally fascinated by its amazing consistency – squeeze it in your hands and it feels like a solid, but release the pressure and watch it slip through your fingers like a liquid!

But what if you don’t have any cornstarch on hand? Or maybe you’re simply looking to have some alternative ways of making oobleck to try with your kids? No problem!

How Do You Make Oobleck Without Cornstarch?

There are plenty of ways to make oobleck without cornstarch. In this quick guide, we’ll take you through the most popular ones and give you a simple step-by-step to follow so you can easily make your own at home.

how to make oobleck without cornstarch

Photo: Jordan Haroldson

Wait…how do you make oobleck again?

Okay, before we get into alternatives, let’s just quickly run through how oobleck is normally made.

Simply mix equal parts cornstarch and water in a bowl until you have a thick, slime-like mixture. If it’s too thick, add more water until desired consistency is reached. If it’s too runny, stir in some more cornstarch.

Be aware that you will need quite a lot of cornstarch to make a large amount of oobleck, so it’s best to have several full boxes to hand if you want to try this activity with a group of kids.

And that’s it! You’re ready to play.

Now let’s take a look at some alternatives…

How to make oobleck in different ways

Photo: The Nordic Nanny

How do you make oobleck without cornstarch?

To find suitable alternatives, it’s important to have a bit of an idea of what gives oobleck its incredible consistency in the first place.

Oobleck, or goop, is a non-newtonian substance. This means that how it behaves changes depending on how much force is applied to it. If you apply more force, the oobleck becomes more solid, like a rubber ball.

But if you release your grip or remove the pressure (for example by dropping the goop from your hand), suddenly it will behave like a liquid and flow away.

The reason cornstarch makes great oobleck is that it’s a type of starch (surprise, surprise!). This means that it’s made up of long chains of glucose molecules which, when mixed with water, create a thick mixture that doesn’t flow away very easily.

So if you’re looking for substitutes for cornstarch, you’ll want to look for other ingredients that have similar properties. We’ll take you through your options below.

Rainbow oobleck sensory play

Photo: Keeping the Crazies Busy 

4 Sure-fire ways to make oobleck without cornstarch

To make perfectly gloopy, non-Newtonian oobleck, you simply need to replace cornstarch with another starch-based flour.

Take a look at our favourite ways to make cornstarch-free oobleck at home using arrowroot flour, tapioca flour, baby powder or potato starch.

Don’t have any of these ingredients?

Then skip this next section and head to the bottom to see if using plain flour, baking soda or baking powder might work for you.

How to make oobleck with arrowroot flour

Arrowroot flour (also known as arrowroot starch – yep, they are the same thing!) is a little harder to get hold of than cornstarch but it can usually be purchased online or in the gluten-free section of your local supermarket/grocery store.

It takes a little bit more work to make oobleck from arrowroot starch because it’s a bit more difficult to mix with water and achieve the right consistency.

However, once you get there, we think you’ll be very happy with the results!

This recipe recommends using 2 1/4 cups of arrowroot flour and 2/3 cups of water. Mix and adjust as necessary until you’ve got some lovely, gloopy oobleck.

Ice cream oobleck sensory activity

Photo: Play and Learn With Luca

How to make oobleck with baby powder

Baby powder is a good alternative ingredient to use if you don’t have any cornstarch in the cupboard at home.

Just mix with water (start with 1 cup of baby powder to 1/2 cup of water and adjust or increase the amounts as necessary).

Baby powder can be very messy (if you’ve ever used it for its intended purpose, you’ll know it has a tendency to fly up in the air and land everywhere!).

Also, baby powders are usually scented, so if you don’t like the scent of whichever brand you have at home, you might want to avoid using it for oobleck as the odour will remain once it’s made.

Can you make oobleck with tapioca starch?

Yes! This is another great option that is a like-for-like replacement for cornstarch.

As with arrowroot flour, tapioca starch and tapioca flour are two different names for the same product.

You’ll likely find it in the same whole food stores or gluten-free section of your supermarket as you find arrowroot flour.

Because it’s starchy, it makes perfect oobleck. Mix it with water in equal parts and stir well. If it is too watery, simply add more tapioca.

Heart valentine's oobleck play for kids

Photo: Pepper and Peep

Can you make oobleck with potato starch?

This is the most complicated way to make oobleck that we’ve come across, but it works just as well.

To make oobleck with potatoes, you need to extract the potato starch. This can be done by pouring boiling water over chopped raw potatoes held in a sieve. Collect the water below and once it’s settled you’ll see potato starch at the bottom.

However, this is a hugely time-consuming process as it takes a lot of potatoes to gather a decent amount of starch.

That’s why we highly recommend you just buy a bag of potato starch online or from your local whole foods store.

Mix it in a ratio of 2 parts potato starch to 1 part water and enjoy!

3 more ways to make oobleck that might work for you

So what do you do if you can’t get hold of any of those starchy cornflour replacements?

Well, the bad news is you’re going to find it tricky to replicate cornstarch oobleck.

The good news is, it might still be possible – and even if you don’t succeed, you should end up with a fun gloopy mixture for your kids to play about with.

You can even make homemade glue with these ingredients too!

halloween sensory oobleck activity ideas

Photo: Mangos and Mayhem

Can you make oobleck with flour and no cornstarch?

Wondering how to make oobleck with flour? Well, unfortunately, it’s not really possible.

If you do want to give it a go, just mix water and plain flour in equal parts and adjust as necessary until you are happy with the consistency.

Replacing cornstarch with flour will give you a pretty different consistency, but it’s still just as much fun to play with.

It will feel and look much more like a paste or dough, but it can still be used for a kids’ sensory activity.

It will be pretty sticky too, which is what makes plain flour and water a great combination if you need some homemade glue.

For example, check out this simple paper maché glue recipe.

Can you make oobleck with baking soda or baking powder?

The important difference here lies between baking soda (bicarbonate of soda) and baking powder.

Baking powder is baking soda with an additional raising agent like cream of tartar plus cornstarch mixed in, so they are not exactly the same thing.

Again, it’s not possible to make oobleck with baking soda on its own, as it isn’t starchy enough to create that gloopy consistency.

Mixing baking soda and water is a fun way to create fake snow though, or a base for a cool acid-base science experiment.

Check out this frozen sea rescue sensory setup, these Halloween potions or this melting Christmas tree activity for more inspiration.

Seaside oobleck activity tray idea

Photo: Palm Tree Parenting

How to make oobleck with baking powder

Some people have had success making oobleck with baking soda by adding in some baking powder too.

For example, this recipe calls for 1/2 cup of water, 4 tbsp baking soda and 4tbsp baking powder.

The baking soda is stirred into the water for several minutes before the baking powder is added.

It makes sense because cornstarch tends to be an ingredient of baking powder, so just check the ingredients on whichever brand you have at home.

If it has cornstarch in it, you should be able to create fun oobleck goop!

It could definitely be worth a try if you’re really in a pinch.

You could also skip the extra baking soda and just use baking powder.

How to store or dispose of your homemade oobleck goop

You can store homemade oobleck in an airtight container, but it may only last a few days.

Alternatively, let it air dry and simply add in more water to refresh it each time your kids want to play with it again.

Keep an eye on the cornstarch for any signs of mould.

Oobleck can easily clog drains so make sure you don’t just pour it down the sink once you’re done with it.

It may look like it’s washing away like water, but once that clever oobleck gets squeezed in your water pipes it may well do what it does best and turn solid. That could cause a serious blockage!

When it’s time to throw it away, let the water evaporate by itself or mop it up with a paper towel before discarding it with your household waste.

We hope you’ve found this quick guide to the different ways you can make oobleck helpful!

Be sure you share with us your homemade oobleck results on Instagram or Facebook and let us know which method you used! #supastem

You might also like this: How to make playdough soft again (3 ways).

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