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The Best Oobleck Slime Recipes

Oobleck Ingredients for Sensory Play

Children scoop and pour oobleck slime into a cup

Are you curious about how to make oobleck slime for a fun kids’ sensory play experience at home or in your classroom? Below is an easy oobleck recipe, as well as alternative oobleck ingredients, to help you succeed! The best part about oobleck liquid is that it provides an opportunity to teach preschool science concepts. This advantage adds to the many other benefits of oobleck sensory play like promoting creativity and supporting cognitive development.

Here are some light science lessons you can teach your littles ones so they can learn through play. Check out Messy Play Kits’ Slime and Oobleck Kits in the Under $15 product list.

What is oobleck slime?

Kids ask such great questions when it comes to oobleck slime like, is oobleck a solid or a liquid? Or, what state of matter is oobleck? Oobleck liquid is a combination of water and cornstarch. It was named after a Dr. Seuss book called, Bartholomew and the Oobleck, where a gooey green substance called Oobleck falls from the sky and causes chaos in the kingdom! Oobleck slime is a non-Newtonian fluid, which means that its viscosity, or flow behavior, changes even at the same temperature. It begins as a runny goo until you apply pressure or stress to it. Then suddenly, it behaves like a solid. This is different from water, a Newtonian fluid, which has a constant flow unless the temperature changes. Then it turns into ice or gas! 

As long as you keep the pressure applied to Oobleck liquid, you can roll it into a solid ball, slam it hard without a splash, and even run across it without sinking! But be careful because as soon as you release the pressure, oobleck turns back into a liquid and will fall through your fingers, relax back into a container, and — if you stand still long enough — make you sink! Try this fun thought experiment with your kiddos: What would it be like if all liquids behaved like non-Newtonian fluids? Can you imagine a river that flowed like Oobleck? Or an ocean that could be walked on really fast without sinking?

Another fun property of oobleck slime is that it’s a shear thickening liquid, which means that if you shear it — or cut it quickly with your fingers like a knife — it will thicken. Blood, on the other hand, is a shear thinning liquid. If you put pressure on it or cut it, it thins! This makes it easier for it to flow through our veins even with extra pressure or a clog. You can show your kids this great video by Crash Course Kids to teach them more about Oobleck and non-Newtonian fluids. Oobleck slime received national attention on the Ellen DeGeneres show because it can be so much fun.

What’s the difference between oobleck liquid and traditional slime?

Although many people call oobleck slime, oobleck is actually different from slime. Slime is made up of borax or sodium borate, which is a mineral and a salt of boric acid. You can find borate in liquid starch or contact solution. When mixed with glue, it creates a stretchy-like substance. Like oobleck liquid, slime is also a solid and a liquid, or a non-Newtonian fluid. However, slime becomes more solid than oobleck and can be stored longer and played with time and time again, while oobleck will spoil after a few days. 

What are the benefits of oobleck sensory play?

Oobleck slime is a great way to engage in sensory play, or any activity that stimulates your children’s senses like taste, touch, smell, sight, and hearing, as well as engages movement and balance. Oobleck sensory play provides your kids time to touch, squeeze, and mold a new material with their hands. They can watch as the substance turns from a liquid to a solid and then back again! If you use a lot of liquid in a larger tub outside, they can even jump and sink into it, or run quickly across the surface. All of these kinds of activities support your children’s brain development all while having fun!

Oobleck ingredients: What are the options?

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Oobleck Recipe with Cornstarch (The traditional and best Method)

This is considered the common, tested, no-fail recipe for oobleck slime.

Materials & Oobleck Ingredients

Oobleck Ingredient Tips

The traditional oobleck ingredients are just water and cornstarch, which is completely taste-safe! If you decide to use the liquid watercolors, mix a few drops of the colorant into the water. Then add the water with the cornstarch slowly and stop when you get to the consistency you desire. The final result should have the consistency of honey. Now, your oobleck slime is ready. It’s time to let your little ones play!

oobleck ingredients in a glass mixing bowl

Oobleck Recipes without Cornstarch

How to make oobleck with flour (a great method)

If your kiddos are ready to make oobleck liquid, but you’re all out of cornstarch, don’t dismay! There are a few alternative options. In order to make oobleck slime with flour, you’ll need to use a high starch option. All-purpose flour will not work. It will just become sticky, so please don’t use it to make oobleck (but do use it for another mushy sensory activity with the paste it creates!). Here are a few oobleck ingredients with flour options:

  • 1 cup arrowroot flour, tapioca flour, or potato starch (the ratio for potato starch should be 2 cups starch to 1 cup water) 
  • ⅓ cup cold water (add 2-3 tablespoons if needed)
  • Liquid watercolors (optional)
  • A plastic tub or bowl

Add all of the oobleck ingredients together in a bowl until the consistency stirs like honey!

How to make oobleck with baby powder (a good method)

  • 1 cup of baby powder
  • 1/2 cup water (varies)
  • Liquid watercolors (optional)
  • A plastic tub or bowl

Did you know that many baby powders have cornstarch in them? If you’re all out of cornstarch and have baby powder with cornstarch in it laying around, you can also use this to make oobleck liquid! However, there are a few things to be cautious about. One, this oobleck recipe is no longer taste-safe. Two, baby powder is fine and can be easily inhaled, so be careful. Three, often baby powder has fragrance, which may be distracting or disturbing for sensory-sensitive children.

How to make oobleck with baking powder (a bad method)

Baking powder also contains cornstarch, which is why this recipe might be thought to work. If you see this recipe online, feel free to try it, but know that it doesn’t work that well to make oobleck slime, but it is a fun separate sensory activity because it fizzes!

  • 1/4 cup of water
  • 4 tablespoons of baking powder
  • 4 tablespoons of baking soda
  • Liquid watercolors (optional)
  • A plastic tub or bowl

Add water to a bowl. Stir in the baking powder for about one minute. When you’re mixing the baking powder, it will bubble and fizz. Wait for that to settle before adding the baking soda. Then, add the baking soda. Since this doesn't make oobleck, the consistency will be different from the other recipes, more like a squishy dough.

How long does oobleck slime last?

Oobleck liquid will only last for a few hours if left out. Eventually, it will become dry. If you want it to last a little longer, then store it in an airtight container and place it in the refrigerator. When your little one is ready to play again, just add a little more water to it and start the oobleck sensory play activity all over again! It will last for a few days, then spoil. 

How to keep the mess contained during oobleck sensory play

Oobleck sensory play can be messy! But that doesn’t have to mean a lot of clean-up. Read some great ideas on getting started with Messy Play that will make your life a little easier as the play facilitator, while your kiddo enjoys the fun. One of my favorite pieces of advice for oobleck is to make it in the bathtub! Your little one can play within a contained space, get it all over themselves, then just rinse off afterward! The sticky substance is safe to go down the drain with enough extra water to thin it out. 

You can also purchase the Messy Play Kits’ Washable Dropcloth  to use under the bowl in case any oobleck slime seeps over the sides. Additionally, you can buy the Mess Maker Apron to keep the oobleck liquid off your kiddos’ clothing.

Oobleck sensory play ideas

Once your oobleck slime is made, you can use it in all sorts of playful ways. Here are a few ideas to get your family started.

Make an oobleck sensory bin and wash station

oobleck and construction vehicle toys in a red container

Fill a large tub with oobleck slime and then add a number of washable toys! I love to use construction trucks, cars, and tools. Let your little ones get extra messy as they move the oobleck around the sensory bin (or in this case, construction site). Then, when they’re done, fill another tub with soapy water and let them practice water sensory play in the wash station! This will not only clean the toys, but it will also teach children responsibility through play as they learn to pick up after themselves all while having fun!

Make an oobleck sensory bag

If you want an activity that’s less messy, try making oobleck liquid then pouring it into a plastic bag that locks at the top. Your child can squish and squeeze the slime, receiving all the benefits of oobleck sensory play, and stay clean!

Pour oobleck through a colander

kids' hands under a colander with oobleck liquid flowing out

Add oobleck slime to a large tub. Then pick up a large handful of the substance and place it in a kitchen colander over the tub. Watch as the solid turns back into a liquid and oozes through the holes in the colander!

Pick up oobleck with a team of loved ones

a group of peoples' hands submerged in a baby pool full of oobleck

If you have a large group of kids, pour oobleck liquid into a large tub. Then have each child push both of their hands deep into the liquid until it hardens. Once the slime has turned into a solid, have the children slowly lift their hands and watch as the tub hovers! This is a great activity for group coordination!

How to facilitate kids in oobleck sensory play

Your children may love this substance, but others may not. If they do appreciate oobleck slime, you can expand their vocabulary by explaining to them what they’re doing as they do it. You can encourage them through words of affirmation as they explore the shifting liquid and solid textures. Additionally, try encouraging them to keep the mess contained in the bowl or bin, as well as guide them to clean up afterward exploring how to teach kids responsibility through play

Oobleck liquid can be a difficult texture for some children. If they don’t like the feeling of oobleck liquid, then try giving them a tool like a fork or spoon to play with so that they don’t have to touch it. Additionally, you can try letting them play with oobleck slime around other children, so that they can observe others before exploring this substance themselves. Repeated exposure may help your children become more comfortable with oobleck sensory play over time. However, if your children continue to dislike the experience of this gooey substance, then don’t push it. It’s important that your child’s boundaries, likes and dislikes, are respected.  

Where to buy oobleck slime

If you don’t want to make oobleck slime at home, then buy it from Messy Play Kits! We sell Oobleck Kits that include all of the ingredients needed, a number of color options (green, pink, turquoise, purple, and orange!), as well as instructions to make this sensory play activity at home or in your classroom. Whether you purchase oobleck from Messy Play Kits, or make it yourself, I hope that you and your family enjoy the mess!

Child holding an Oobleck Kit from Messy Play Kits