cartoon robot



Use the natural properties of lemon juice to write a secret message in invisible ink and reveal it with the application of a little heat!


  • Lemon juice
  • White paper
  • Small paintbrush
  • Iron, light bulb, or hairdryer


  • Have each little scientist write a hidden message on a piece of paper with the lemon juice and paintbrush. Let dry.
  • Once the lemon juice has dried, carefully apply heat with an iron, being careful not to burn the paper. (A hair dryer works as well, but takes longer.)
  • Sit back and let your message appear!

Spark Creative Learning!

Lemon juice is virtually invisible but oxidizes and turns brown when heated. This reaction to heat is the perfect way to create secret messages for science parties or secret laboratory formulas! The lemon juice is invisible when dry, but once you add heat, the message is revealed!

This entry was posted in M's Blog and tagged , , , , . Bookmark the permalink. Both comments and trackbacks are currently closed.