Red cabbage contains a pigment called anthocyanin that changes color depending on whether a substance is an acid, base, or neutral. By extracting this pigment, you can test common household liquids to see where they fall on the acid-base scale.

1. Tear red cabbage leaves into small pieces and place them in a sealable plastic bag.
2. Add about one cup of water, press out the air, and seal the bag.
3. Squish the cabbage pieces in the water until the liquid turns dark blue.
4. Pour the liquid into a cup and discard the cabbage pieces. This is your indicator solution.
5. Place about one tablespoon of the indicator into a small cup.
6. Add a few drops of the substance you want to test using a straw or dropper.
7. Observe the color change and record your results.
8. Use a fresh cup and new indicator liquid for each test.

Red Cabbage Indicator Colors : Chemistry Experiment for Kids to do at Home - Yucky Science:

Science at Home - Red Cabbage pH Indicator - The Sci Guys (more detail and theory):

📄 Red Cabbage Indicator - ACS: https://www.acs.org/education/activities/red-cabbage-indicator.html

• Try testing different types of fruit juices to compare their acidity.
• Test a range of cleaning products (excluding bleach) to see which are basic.
• Use the indicator on paper (soak paper strips in indicator, dry them, then use as test strips).
• Use other natural indicators such as blueberry juice.

• Wear safety glasses or goggles when handling liquids.
• Do not eat or drink any of the substances tested.
• Work with an adult, especially when handling cleaning products.
• Wash hands before and after the activity.
• Tie back long hair and avoid loose clothing near liquids.
• Dispose of solid waste in the trash and pour liquids down the drain with plenty of water.

• Why does the cabbage indicator turn red or pink in acids but green or yellow in bases?
• Which household items were more acidic than you expected? More basic?
• Why is water considered neutral?
• How does this demonstration relate to the pH scale used in chemistry?
• Could other plants with natural pigments be used as acid-base indicators?