Looking for a hands-on chemistry experiment you can do at home or in the classroom? This red cabbage pH indicator experiment is a fun and visual way for kids to explore acids and bases using everyday materials. Watch liquids change color and learn what it means for something to be acidic or basic.
Red Cabbage Experiment
This activity makes a perfect addition to any chemistry or kitchen science unit. It’s a great way to introduce the pH scale, practice observation and prediction skills, and tie into discussions about chemical reactions and the scientific method.
Field of Science: Chemistry
Grade Level: 2nd – 6th Grade
Concepts Explored: Acids and bases, pH scale, Indicators, Color changes, Observations, and hypothesis testing
NGSS Alignment (Simplified)
What will kids figure out?
How can we test if something is an acid or a base?
What will kids do?
They will make a natural pH indicator from red cabbage to test various household substances.
What will kids learn?
They will learn about the pH scale, chemical indicators, and observable color changes caused by acids and bases.
Cabbage Experiment Supplies Needed:
- 1 head of red cabbage
- Medium saucepan
- Water
- Strainer
- Several small jars or clear cups
- Acidic and basic household items to test:
- Lemon juice
- Vinegar
- Baking soda solution
- Black coffee
- Soapy water
- Seltzer or soda
- Optional: pH strips or coffee filters to make DIY indicator strips
- Printable worksheets or a science journal (see below)
How to Make a Red Cabbage pH Indicator
🔎 Learn more about pH, acids, and bases here.
Chop the Cabbage
Roughly chop the cabbage into small pieces.
Boil the Cabbage
Place the cabbage pieces in a saucepan with enough water to cover. Bring to a boil and let simmer for 5–10 minutes.
Let It Sit
Turn off the heat and allow the cabbage water to steep for 20–30 minutes.
Strain the Juice
Strain out the cabbage pieces and pour the purple liquid into jars. This is your natural pH indicator!
💡 Tip: You can dilute the cabbage juice slightly with water and it will still work for testing!
How to Test Acids and Bases
Choose common kitchen liquids and add a spoonful or squirt into a jar of cabbage juice. Watch the color change and record your results. Learn more about acids and bases here.
🛑 Please take care when mixing different items into your cabbage pH indicator. Adult supervision is recommended at all times. This NOT an edible science experiment!
| Item | Predicted pH | Color Change |
|---|---|---|
| Lemon juice | Acidic | Red or pink |
| Baking soda solution | Basic | Blue or green |
| Vinegar | Acidic | Red |
| Coffee | Slightly acidic | Purple to reddish |
| Soap or cleaner | Basic | Green or yellowish |
🔎 Encourage kids to make a hypothesis before each test:
“If the ____ turns the cabbage juice ____ then it’s an acid/base.”
What Is a pH Indicator?
pH stands for “potential of hydrogen” and tells us how acidic or basic a substance is on a scale from 0 to 14:
- 0–6: Acidic (sour)
- 7: Neutral (like water)
- 8–14: Basic (bitter, soapy)
Red cabbage contains a pigment called anthocyanin, which reacts to pH levels and changes color depending on whether it’s mixed with an acid or base. That’s what makes it such a great natural pH indicator!
Free Printable Red Cabbage Experiment Journal Page
More Science Facts for Kids
- Lemons and vinegar are acids—think sour taste!
- Baking soda and soap are bases—often bitter or slippery.
- You can make your own pH strips by soaking coffee filters in cabbage juice, letting them dry, and cutting them into strips.
Make It a Science Project
Turn this experiment into a complete science fair project!
- Ask a question: “What household liquids are acids or bases?”
- Make a hypothesis for each test.
- Record your observations using a journal or a printable chart.
- Share your results and what you learned!
💡 Learn about the scientific method, writing a hypothesis, and choosing variables here.
pH Extension Activities
- Create your own pH scale poster using tested liquids and their resulting colors.
- Try testing different types of cabbage or other vegetables with anthocyanins.
More Fun With Acids and Bases
Simple chemistry is cool! Check out more than 65 chemistry experiments for kids for more ideas!
- Lemon Battery
- Make Invisible Ink
- Try Fizzy Lemonade
- Erupting Lemon Volcanoes
- Cranberry Chemistry Experiment
- Baking Soda and Vinegar Science
Printable Science Projects For Kids
If you’re looking to grab all of our printable science projects in one convenient place plus exclusive worksheets and bonuses like a STEAM Project pack, our Science Project Pack is what you need! Over 300+ Pages!
This is an awesome experiment to do, even for older kids! It shows them that chemistry is very much a part of our lives and are closer to us than we think! I’m sure kids would love it 🙂