Mr. Russell’s Classroom: Lemon Juice Isn’t Just For Lemonade

It’s time for Mr. Russell’s classroom. Today J-Stace the Science Ace proves lemon juice isn’t just for lemonade, it can also double as ink for your secret messages.


What You Need

  • lemon juice
  • a cotton swab
  • a piece of paper
  • a cup
  • a lighter



  • Add about 1 tablespoon (15 ml) of lemon juice to the cup. Fresh squeezed or bottled juice will work just fine.
  • Soak an end of the cotton swab or put the paintbrush into the lemon juice. You’ll use this to write your message.
  • Write your message on the plain paper. You’ll be able to see it as long as the paper is wet so let the lemon-juice message dry completely.
  • Bring your heat source (a lighter) close to the paper and watch as your secret message magically begins to appear!


Science Behind the Experiment

How Does the Experiment Work?

Lemon juice – like most fruit juice – contains carbon compounds. These compounds are pretty much colorless at room temperature.

Heat breaks down these compounds and releases carbon. When carbon comes in contact with air (specifically oxygen), oxidation occurs and the substance turns light or dark brown. If it oxidizes long enough, it can go all the way to black.


Science Words of the Day

Oxidation: Oxidation is a process in which a chemical substance changes because of the addition of oxygen.



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