Secret message

Secret message

What secret message might you write to your friends in this cool experiment?

Ingredients and equipment that you will need

A leaf of red cabbage
Soda crystals (from any supermarket)
Blotting paper
Paint brush

Method and further information

You can use a red cabbage indicator to make secret messages.

Dissolve a dessertspoonful of soda crystals in water and write with it onto the blotting paper. Let it dry and you can’t see what you’ve written. Then paint the paper with red cabbage juice and the message is revealed.

Be careful – you should ask an adult to help you with these experiments. Do your experiments in old yoghurt pots, jam jars or bottle tops. Don’t use cups or glasses in case someone thinks it’s a drink.