Thanks to ELG’s Tiffany Chen for allowing us to cross-post from her blog, SpeechWithinReach SLP.

Have a secret message to share or a surprise to reveal? Here’s a fun science activity to try at home! 

How to make the Invisible Ink?

First, pour 1/4 cup (60ml) of water into a bowl, and add 1 tablespoon of baking soda into a bowl.

Next, mix everything together.

Then, dab a cotton swab into the water mixture and write your secret message on a paper!

How to reveal the secret message?

First, measure out 1/4 cup (60ml) of grape juice.

Next, use a brush or tissue to gently apply the grape juice all over the paper.

Then, watch the baking soda and acid from the grape juice react and change color!

Click here to watch the video!

What can I teach my child?

1. Language:

  • Sequencing: Support your child to share the step-by-step sequence of how to make invisible ink with friends, then they can write each other messages.
  • Following multi-step directions: Although simple, you have to use the right type of liquid to get the best results! Remind your child to keep their listening ears on!

2. Literacy/Pre-literacy skills

  • Recognizing letters: What letters are written on the paper?
  • Putting sounds together: Reveal one letter at a time and ask your child to try and blend the sounds together.
  • Building sight words: Ask your child to write a word as you dictate it to them, or recognize common words in the message.


3. Science:

  • Making predictions: What will happen when the grape juice hits the paper? Will you see a color change?
  • Compare and contrast: What would happen if you used orange juice instead of grape juice?

Sometimes the simplest ingredients can make the best activities!

Send a photo of your secret message to the ELG WeChat account for a chance to get a gift from us!

Looking for more fun ways to introduce language? Check out our other activities in the series: Science with Toddlers and Young Children