How To Make Oobleck Step-By-Step Tutorial | STEM + Sensory Learning Activity Ideas

Oobleck is a funny mixture of water and cornstarch that acts like both a liquid and a solid! It's a great taste safe activity for messy sensory play with toddlers or as a STEM lesson for preschoolers and elementrary school aged kids. In this post, discover how to make oobleck with a step-by-step tutorial, plus STEM activities and holiday themed sensory learning activities using it!

Oobleck ingredients:

Cornstarch and water.

That’s it! Two ingredients you probably already have in your kitchen! 

If you want to spice things up or theme your oobleck for sensory learning play, you can add some food coloring and toys too – like I did in this fall activity!

What is oobleck?

Oobleck is a non-Newtonian fluid. Sounds fancy, right?

It basically means it’s not quite a liquid, or a solid; and it can act like both!

Oobleck is known as the original slime; and parents will love that it's much easier to make than play dough or slime! They don't need to fret about their kid getting it in their mouth either! AND it still provides just as much fun and sensory learning! Seriously, it’s so easy to make, a toddler can even do it!

It’s great for young children (taste safe!!) and for older ones (STEM lessons!!) in teaching how changes in pressure can change the properties in how some materials behave.

In laymen’s terms: think how cool air applied to water freezes it and heat applied to it melts it.

Hard pressure applied to oobleck solidifies it, and light pressure causes it to act like a liquid.

oobleck ingredients and recipe

Oobleck Recipe:

  • 2 cups of cornstarch
  • 1 cup of water
  • Optional: food coloring

Step-by-Step Instructions On How To Make Oobleck:

Add your cornstarch to a bowl, then add the water and mix!

Tip: If you’d like to color your oobleck, add the food coloring to the water BEFORE adding the water to the bowl. 


  • If you find your oobleck doesn’t form a solid and is too watery, simply add a little more cornstarch. 
  • If you find your mixture is too solid and isn’t liquidy, add more water

How long does oobleck last?

Oobleck should be used that day. However you can add water to it to revitalize it as it begins to dry out if you want to use it the next day.

How do you clean oobleck?

Hot water cleans ooblecks right out! Simply add some hot water to a dish towel and wipe your counters, hands, or container clean. You may want to run the hot water in your sink for a little to ensure the mixture fully melts away.

The other option to clean oobleck is letting it dry out. This is my go-to option to continue the play! Let the oobleck dry out overnight, then let your kid smash it into pieces (or “excavate” their toys) and throw it away when you finish.

how to make oobleck

STEM Activity Checklist with Oobleck:

  • Quick pressure: hit the oobleck with a spoon and notice how the viscosity increases when the cornstarch particles are forced together. 
  • Slow pressure: Slowly scoop your spoon into the mixture and notice how it acts more like the water in the recipe. Have your child move the spoon (or fork) through the mix slowly and see how it glides. Then have them apply more pressure and go fast and see how it gets stuck!
  • Make a ball: again cornstarch particles moving together form a solid you can mold in your hands!
  • Relax your hand: after forming a ball, relax the hand and notice how the release of pressure melts your ball away

Holiday Themed Oobleck Activity Ideas:

Oobleck is great on it's own! But my toddler especially loves the add-ins to theme the activity! Here are some ideas for things to add to your oobleck sensory learning experience!

  • Fall Sensory Oobleck using fall foliage and items from nature (rocks, pine cones, acorns, leaves, twigs, etc.)
  • Back To School Oobleck: Use a crayon box for this one! Pencils, ruler, crayons, mini apple or wooden apples, play glasses, etc.
  • Halloween Oobleck: Dye oobleck green and add to a witch's cauldron! Add eyeballs, spiders, worms, etc. OR Use a carved out mini pumpkin and dye the oobleck orange add in the same items or just use the pumpkin seeds. You could even cut a jack-o-lantern face to have the oobleck ooze out
  • Thanksgiving Oobleck: Mini gourds, corn, feathers, cranberries, etc.
  • Hanukkah Oobleck: Dreidels, gelt, candles, mini menorah
  • Winter Oobleck: Option 1: cranberries, pinecones, evergreens, snowflakes; Option 2: Arctic oobleck! Dye it blue or leave it white, add in penguins, polar bears, whales, etc.
  • Christmas Oobleck: Dye oobleck red or leave it white and add in santa, reindeers, bows or presents, candy canes, etc.
  • New Years Oobleck: Add blow horns/tassels, confetti, and anything sparkly!
  • Mardi Gras Oobleck: Create purple, green, ,and yellow oobleck, then pour into a tray and add in Mardi Gras beads, masks, and whatever else you can find!
  • Valentine's Day Oobleck: Dye your oobleck red or pink (or leave it white), add in hearts and baby cupids
  • St. Patrick's Day Oobleck: Dye your oobleck green, add in leprechauns, gold, rainbows, shamrocks, etc. ALTERNATIVELY make rainbow oobleck (separate batch of oobleck for each color of the rainbow) poured into a counter with St. Patty's themed items!
  • Easter Oobleck: Add eggs, bunnies, spring flowers, chick-a-dees, etc.
  • July Fourth Oobleck: Add red, white, and blue items, flags, etc.

How long does it take to set up and clean up oobleck?

It takes about 2-5 minutes to set up oobleck, which your child can help with.

Clean up varies based on how messy you get while playing! I'd suggest doing this activity outside or with a splash mat under you. What tends to happen is little hands go into the mixture, the mix is solid from their force, then melts away as they are moving their hands onto the next thing. While it melts away, it likely will melt on the chair/floor where your child is playing.

While it's easy to clean (just wipe it away), depending on how much your child flails their hands, the oobleck could get EVERYWHERE since it does run like a liquid when there's no pressure applied.

And that's how you make oobleck! Tell me, have you made oobleck before? How'd it go?!

11 No Mess Fall Toddler Activities You NEED To Try At Home

Fall Toddler Activity: Contact Paper Tree

Fallen Leaves: Montessori Glue Box Activity

Fall Toddler Activity: Montessori Fall Smelling Jars

No Mess Fall Toddler Activity: Sticker Shapes

EASY No Mess Pumpkin Activity For Toddlers: Sticky Pumpkin

Pumpkin Bath: Easy Toddler Activity For Halloween Or Fall

Pumpkin Fine Motor Activity For Toddlers To Do At Home This Halloween Or Fall

11 Fun + Easy Halloween Activities For Toddlers: Sensory Learning

21 Free Printable Halloween Color Pages + Activities For Kids

Halloween Activity: Apple Stamped Pumpkin Craft For Young Children

Halloween Toddler Activity: Spatula Pumpkin Craft!

How Do You Make A Witch Hat Out Of Paper? Dollar Tree Halloween DIY!

How To Set Up A FAST Halloween Sensory Paint Activity For Toddlers

Halloween Matching Game – Free Printable for Toddlers + Preschool Kids

Thanksgiving Toddler Activity: Feed The Turkey

EASY Thanksgiving Toddler Activity: Turkey Run

100 Halloween Books For Kids [For Babies, Young and Older Children!]

The Ultimate List of Halloween Movies [100+ from Scary to Not-So-Scary!]

97 Thanksgiving Children’s Books For The Whole Family To Read