Outreach: red cabbage pH indicator


This is a hands-on experiment that explains the measurement of pH using red cabbage indicator paper. Are household solutions acidic or alkaline/basic?


These resources were created for the Cambridge science festival 2013.


These resources were created for the Cambridge science festival 2013.

If you teach primary science, click the headings below to find out how to use this resource:

Skill development

Children will develop their working scientifically skills by:

  • Drawing conclusions and raising further questions to be investigated, based on their data and observations.
  • Asking their own questions about scientific phenomena.
  • Selecting and planning the most appropriate ways to answer questions, including:
    • Grouping and classifying things.

Learning outcomes

Children will:

  • Group substances according to whether they are acidic, neutral or alkaline.
  • Compare and group together everyday materials on the basis of their properties.

Concepts supported

Children will learn:

  • That substances can be acidic, neutral or alkaline, and that tests can be performed to determine which of the three a substance is.

Suggested activity use

You can use this activity as a whole-class investigation, allowing children to group substances into acids and alkalis. It will provide opportunity for discussion and questioning.

Alternatively, you could use this resource as part of a science week or at a science club.

Practical considerations

The red cabbage juice indicator can be prepared the prior to the lesson, which will save time.

A range of different substances to test will be required.