Red Cabbage pH Experiment for Kids: Acids & Bases

Have you ever seen a purple liquid turn bright red or green in seconds? No, it’s not magic — it’s science! Specifically, it’s one of the most exciting and simple chemistry experiments for kids that you can do right at home. And the secret ingredient? A red cabbage.
In this article, we’ll show you how to create a natural pH indicator from red cabbage and use it to test different household liquids. This hands-on activity is perfect for children aged 6 to 12 and introduces them to basic chemistry concepts in a fun, colorful way. If you’re a parent, homeschooler, or teacher looking for an easy and safe way to spark curiosity in science, this is for you.
A Kid-Friendly Explanation
PH is a scale scientists use to figure out if something is acidic, neutral, or basic (alkaline). Here’s a simple way to understand it:
- Acids: Sour things like lemon juice and vinegar
- Bases: Slippery things like baking soda and soap
- Neutral: Balanced, like pure water
The pH scale ranges from 0 to 14. Acids are lower on the scale (closer to 0), bases are higher (closer to 14), and neutral sits right in the middle at 7.
Now, instead of just hearing about pH, kids can see it in action through a color-changing science experiment. That’s where red cabbage comes in!
How to Make a Red Cabbage pH Indicator at Home
Red cabbage contains a natural pigment called anthocyanin that changes color depending on the pH level of what it touches. It’s completely safe and found in your grocery store — no fancy lab equipment needed.
Here’s what you’ll need:
- ½ head of red cabbage
- Hot water
- A blender or a pot for boiling
- A strainer or sieve
- Clear cups or jars
- Household test liquids: lemon juice, vinegar, soap water, baking soda water, cola, tap water, etc.

Instructions:
1:Chop the cabbage into small pieces.
2:Blend it with hot water, or boil it for 10 minutes. Let it cool.
3:Strain the purple liquid into a container — this is your natural pH indicator.
4:Pour a small amount of the cabbage juice into each cup.
5:Add different liquids into each cup, one at a time, and watch the colors change!
Kids will love seeing the rich purple turn to pink, green, or even yellow depending on the liquid’s pH level.
Is It Safe?
Yes — this experiment is safe for children. All ingredients are non-toxic and commonly found in kitchens. Still, here are a few tips:
1: Supervise young children, especially when handling hot water or glass jars.
2: Wear aprons or old clothes (cabbage juice can stain!)
3: Don’t taste or drink the test liquids or cabbage juice
With these simple precautions, it’s a great indoor science experiment for kids to do at home or in class.
Why Does the Color Change?
When you add a substance to the red cabbage indicator, the anthocyanin reacts based on the pH of the liquid:
1: Acidic liquids (like lemon juice or vinegar) turn it pink or red
2: Basic liquids (like soap or baking soda) make it turn blue, green, or yellowish
3: Neutral liquids (like water) keep it purple

This chemical reaction is a simple way to visualize the invisible world of acids and bases — and it’s safe, exciting, and completely kid-friendly.
PH Art Project
Turn your science lesson into an art project! Here’s how:
1: Use watercolor paper or coffee filters
2: Paint the paper with cabbage juice using a brush or sponge
3: Then use a cotton swab dipped in lemon juice, baking soda water, or soap to draw or write messages
4: The colors will change as the acids and bases react on the paper
Kids can create color-changing artwork while learning about chemical reactions. It’s STEM + creativity = magic!
Real-World Uses of pH Science
This isn’t just a fun experiment — it introduces real science concepts with real-life applications. Here’s how pH is used in everyday life:
1: Doctors and nurses use pH testing to check for health issues, like infections or dehydration.
2: Farmers and gardeners test soil pH to grow healthy crops.
3: Pool owners measure water pH to keep it clean and safe.
4: Food scientists monitor pH when making cheese, yogurt, pickles, and other foods.
5: Even in skincare, pH helps decide whether a product is gentle or harsh.
So when your child is experimenting with red cabbage juice, they’re getting a glimpse into the real world of science.
Want More Science Fun?
If you want more science fun, explore more on our blog:
10 Fun and Easy Homemade Science Experiments for Kids to Try at Home
Conclusion: Science in Every Color
This red cabbage pH experiment is more than just pretty colors — it’s a powerful way to teach children how the world works. From acids and bases to real-world chemistry, your child is learning through discovery, not just memorizing facts.
And the best part? It’s fun, safe, and done with simple ingredients already in your home.
So the next time you see a red cabbage in your fridge, remember — you’re not just making salad… you could be making a scientist.