Do you want to write cool, invisible messages to your friends and family members? Well, this is easier than you might think! All you need to do is gather a few items from around the house and you can make your own invisible ink!
What you need:
- Baking soda
- Water
- Cranberry or grape juice
- Cotton swab
- Paintbrush
- White paper
Steps:
- Mix equal parts of baking soda and water together (I used 1 tablespoon of each).
- Use your cotton swab to write a secret message on your paper.
- Allow the message to dry.
- Use your paintbrush to brush the cranberry or grape juice over your secret message.
- Watch the message magically appear!
What makes the message appear?
Baking soda has a pH of 8, which means it is a base. Since baking soda is white, when we write with the baking soda and water mixture on the paper, it blends in with the paper and does not appear. Cranberry juice has a pH of about 2.5, which makes it an acid. The cranberry juice also has a specific molecule in it that acts as an acid-base indicator, which means it can change colors depending on the amount of acid or base present. When the cranberry juice is brushed onto the basic message, the message turns a different color than the paper due to their differences in pH.