Make magical oobleck at home with just water and cornstarch. A simple, hands-on science experiment kids will love!
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Learning how to make oobleck is a fantastic spin on a classic science favorite. This DIY activity is messy in the best way, sensory, imaginative, and surprisingly simple with just water and cornstarch you probably already have at home. Perfect for rainy afternoons, after school play, or anytime you want to spark curiosity and keep little ones engaged. Once you’ve nailed the basic mixture, the real fun begins. Try adding bold colors like lava red, ocean blue, or galaxy black. Or make it an adventure with themed batches like alien sludge, enchanted forest mud, or sparkly space dust that looks straight out of a science fiction story.
It’s also an affordable, hands on hit for birthday parties. Kids love making their own oobleck right at the table, and you can even prep individual cups for goodie bags or set up a DIY oobleck station for everyone to explore. This squishy, drippy mix is perfect for tactile play and open ended creativity. Just remember, it’s safe for little fingers but not for eating, so younger children should be supervised while playing.
This quick Oobleck recipe makes a thick, squishy mix that can feel solid when you move fast and runny when you go slow. It is perfect for sensory play and simple kitchen-table science. The activity is low cost, easy to manage, and only takes a few minutes to set up. More than just a craft, Oobleck turns science into something you can touch. Follow these easy Oobleck instructions by trying fast taps, then a slow press. Roll the mix into a ball and watch it drip apart, or push toy cars across the surface to see the tracks. Remember it is safe but not for eating. For cleanup, scrape leftovers into the trash before rinsing your bowls and spoons.
Watch How to make Oobleck
Instructions
1 cup cornstarch (called cornflour in some countries), ½ cup water (room temperature), Optional: a few drops of food coloring or liquid watercolor, Bowl and spoon/spatula, Tray or rimmed baking sheet
Add 1 cup cornstarch to a bowl. Pour in ½ cup water and mix. At first it may feel like the spoon is stuck and that resistance is normal.
Scoop some up and squeeze: it should feel firm in your hand, then melt and drip when you loosen your grip. If it runs like milk, stir in 1–2 tbsp cornstarch. If it’s crumbly and won’t flow, add 1 tbsp water and mix.
Add Color - Mix in a few drops of food coloring for a bold look or use less for pastel.
Play and explore! Try punching the surface (it resists!) and then slowly pressing a finger (you’ll sink). Drop a small toy on top and compare what happens when you tap fast vs. press slowly.
My oobleck is too runny. How do I fix it? Sprinkle in 1–2 tbsp cornstarch, mix, and test again. Repeat until it firms when squeezed but flows when you relax. My Oobleck is dry and crumbly. How do I fix it? Add 1 tbsp water at a time and stir. Stop when it oozes smoothly from your hand. My Oobleck won’t “go solid” when I press it. Your ratio is likely too wet. Add cornstarch and try quick, firm taps—oobleck stiffens under fast force.
Final steps
You're almost there! Complete all the steps, bring your creation to life, post it, and conquer the challenge!
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