How to Make Rock Candy

Believe it or not, rock candy was originally used by pharmacists as a base for medicines [source: Origin of Rock Candy]. Today rock candy is sometimes used to soothe sore throats.

Here's what you need to make rock candy:


  • A large saucepan
  • A long wooden spoon
  • A tall clean glass jar
  • Clean cotton string, shorter than the height of the jar
  • A pencil or skewer
  • A paperclip, sterilized
  • 1 cup (236.6 milliliters) water
  • 2 cups (473.2 milliliters) granulated sugar
  • Food coloring and flavoring (optional)

Got everything? Great! Let's make some rock candy.

  1. Tie one end of the string around the pencil or skewer.
  2. Tie the paperclip on the other end of the string so it hangs straight down.
  3. Moisten the string and roll it in the sugar.
  4. Lower the paperclip into the jar until the pencil or skewer rests on the mouth of the jar.
  5. Boil the water in the saucepan.
  6. Add the sugar slowly to the boiling water while stirring.
  7. Continue stirring until the sugar dissolves.
  8. Remove the pan from the heat.
  9. Add food coloring and flavoring, if you want.
  10. Pour the hot sugar-water slowly and carefully into the jar
  11. Set the jar in a safe place for three to 10 days. Sugar crystals will begin forming on the string in a few hours. The longer you leave it, the more the crystals grow. Don't let them grow for too long or you may not be able to get the candy out of the jar!
  12. Place the jar in a shallow bowl of water and a little detergent, to prevent ants from getting to it.
  13. Pull the string gently out of the jar when the rock candy is large enough.
  14. Break pieces off the string and store them in a tightly covered container [source: Making Rock Candy].