You and the kids can make your own natural pH indicator and watch it change colour as you add everyday ingredients from the kitchen. So grab yourself a red cabbage and let’s get started with this simple experiment from Tūhura Otago Museum!
Method
- Take a red cabbage and chop finely
- Soak red cabbage in boiling water for 5 min
- Drain and collect the purple/blue water
You have now made yourself a natural pH indicator!
Due to a small molecule found in red cabbage, called anthocyanin, the liquid will change colour depending on what you add to it. In its neutral form anthocyanin is a blue/purple colour, drop the pH by adding an acid and it will change to a lighter pink colour, add a base and it will become a darker blue.
Add a few different things from your kitchen and find out if they are acidic or basic! Hint try lemon juice/vinegar and baking soda.
Try more: Make your own poppin’ pufferfish! >>
