Red Cabbage Indicator

Key Stage 3

Red cabbage indicator is a pH indicator made from the leaves of a red cabbage.

The colour of the red cabbage leaves is caused by a dye that can change colour in different pH.

Red cabbage pH scale.

Examples of the red cabbage indicator at different pH values.

1. Tear 20g of red cabbage leaf into small pieces and place into a 500ml beaker.

2. Add 300ml of hot water to the beaker.

3. Stir with a glass rod for 3 minutes.

4. Place a funnel in a conical flask and place some filter paper in the funnel.

5. Filter the red cabbage and water mixture by pouring through the filter paper into the conical flask.

6. The filtrate is your red cabbage indicator. You can use a pipette to add small amounts to solutions to find their pH.