What You Need
- Bicarbonate of soda
- water
- a red grape
- a cotton wool bud
What To Do
- Add one tablespoon of bicarbonate of soda to a cup of water
- Dip your cotton bud into the mixture and use it (like a pen) to write your message on some paper
- When it's dry, rub a red grape over your secret message and watch it appear, like magic