How to Make Oobleck with Cornstarch: A Fun Science Activity for Kids (15 Minutes!)
Looking for an exciting science experiment that doubles as sensory play? Learn how to make oobleck with cornstarch in just 15 minutes! This magical 2-ingredient mixture transforms from liquid to solid right before your eyes, making it the perfect hands-on activity for toddlers and preschoolers. Inspired by Dr. Seuss’s ‘Bartholomew and the Oobleck,’ this simple science experiment will amaze your little ones while teaching them about non-Newtonian fluids.
Perfect for ages 2-8
Prep time: 5 minutes
Play time: 15-30 minutes
Get ready to embrace the mess!
What is Oobleck? The Science Behind the Magic
Oobleck is a fascinating non-Newtonian fluid that behaves like both a liquid and a solid. When pressure is applied, it becomes solid, but when left alone, it flows like a liquid. This unique property makes it an excellent tool for teaching children about states of matter in a hands-on way.
Each summer in my childcare, we welcome some older school-age children. I give them freedom to choose activities, from art to science experiments. One group was REALLY into slime and all things messy. When they suggested making oobleck, I knew we were in for an exciting science adventure!
Ready for more Dr. Seuss related fun?! Weve got you covered!
The Cat in the Hat, Easy Dr. Suess Activities
One Fish Two Fish, Easy Dr. Suess Activities
Green Eggs And Ham, Easy Dr. Suess Activities
Simple Ingredients You Need for Oobleck
Two ingredient recipes are my favorite, all you will need is cornstarch and water.
Essential Ingredients:
- ½ cup water
- 1 cup cornstarch
You may also want a fork to get started or for those kiddos who aren’t quite ready to jump in. A spoon isn’t going to cut it. We used forks to push and scrape the mixture in the beginning. Eventually they ditch the fork for their fingers and that’s when the magic begins.
Optional Materials:
- Food coloring
- Small plastic toys for enhanced play
- Smock or old t-shirt
- Tablecloth or kraft paper
- Bowl or container with sides
- Fork for initial mixing
- Small container with lid for storage
- Wet washcloth and broom for cleanup
Step-by-Step Instructions: How to Make Oobleck
We’ve tested many recipes, and this 2:1 ratio of cornstarch to water consistently gives the best results.
- Add water and a few drops of food coloring to a measuring cup
- Measure 1 cup of cornstarch into your bowl
- Pour colored water over cornstarch
- Mix everything together until combined
Pro Tip: If the mixture seems too runny, add more cornstarch one tablespoon at a time. If it’s too thick, add water one teaspoon at a time.
It’s as simple as that!!
Fun Ways to Play with Oobleck (with Learning Questions!)
Now comes the exciting part – experimentation! Here are some fun activities and questions to explore with your children:
Exploration Activities:
- Try forming a ball with the oobleck
- Watch it transform from solid to liquid in your hands
- Add small toys and observe how they interact with the mixture
- Practice pouring and catching the oobleck
Learning Questions to Ask:
- What happens when you hold the oobleck?
- Is it a solid or a liquid?
- Do toys sink or float in the mixture?
- How does it feel? Is it smooth or rough?
- What happens when you move your fingers through it quickly vs. slowly?
These questions help develop scientific thinking and observation skills while children play!
Tips for Managing the Mess (Parent-Tested Methods)
Don’t let the potential mess stop you from trying this amazing activity! Here’s how to keep things under control:
Preparation is Key:
- Cover your workspace with a disposable tablecloth or kraft paper
- Dress children in smocks or old t-shirts (cut up the sides for easy removal)
- Have cleaning supplies ready before you start
- Keep materials away from counter edges (learn from my colored-water mishap! You can read about that below)
Setting Clear Expectations:
There is nothing wrong with setting clear rules before beginning. In fact, it’s important. Keep it simple, discuss what they can and cannot do. Kids are smart, kids can be great with boundaries and rules if you give them the chance.
In fact, the more you remind them of the expectations prior to beginning a messy project, the more they remember, the easier your projects will be going forward.
Be sure to ask if they have questions about what you said or if they understand.
One of the things I say to my group before we begin is remember we love to be messy, but we need to contain our mess. We say this when playing in sensory bins and muddy areas outside as well. Recently a little boy asked, ‘what does contain mean?’
This was a great learning moment for me as well as for them. Make sure they know what you mean.
I think one thing holding most people back from trying oobleck or other similar projects is the mess. So, before you begin know that mess will happen, but if we’re prepared then it’s okay!!
Storage and Clean-Up: What to Do After Play
Storage Tips:
- Store in an airtight container for up to 3 days
- Watch for any changes in color or signs of mold
- Keep at room temperature
Disposal Instructions:
- Wipe surfaces with damp cloth
- DO NOT pour down the sink
- Dispose of oobleck in the trash
- Roll up kraft paper or tablecloth with any dried pieces
Keep it simple
No matter what project you are doing, keep it simple for yourself and for the children in your care.
You do not need 50 tools and all the color options. You do not need to add any toys to this if you don’t want to. Whatever you provide, I guarantee they are just excited to try it out!
Keep messy items away from the edge of the counter.
This may be more of a reminder for myself…
The last time we made oobleck, I set my measuring cup with 2 cups of colored water on the counter and walked away for a moment. Little did I know my ‘apparently tall enough to reach the counter’ one year old was curious and headed straight for it.
It’s just colored water…but it was everywhere. I was not prepared to mop the floor at that moment but that’s exactly what I did.
I’ve always been a little leery of food coloring for obvious staining reasons. Once upon a time I thought I was going to make soap and got this color pack. It’s great! We haven’t had issues with staining and it’s non-toxic.
Frequently Asked Questions
Is oobleck safe for toddlers?
Yes! Made from cornstarch and water, oobleck is non-toxic. However, always supervise children and ensure they don’t eat it.
How long does oobleck last?
When stored in an airtight container, oobleck can last 2-3 days. Discard if you notice any changes in smell or appearance.
Can you make oobleck without cornstarch?
While cornstarch works best, you can use potato starch as an alternative. However, the consistency might be slightly different. We have not tested this out, but others have with success
Why is it called oobleck?
The name comes from Dr. Seuss’s book “Bartholomew and the Oobleck,” where a sticky green substance falls from the sky!
Remember, the best learning happens through play, and sometimes the messiest activities create the most memorable experiences. Embrace the chaos, prepare accordingly, and watch your little scientists discover the amazing properties of oobleck!
Be prepared and embrace the mess!
