rock candy contains sugar

Making candy doesn’t have to be intimidating, especially when science does the work for you. Rock candy is the product of a process called precipitation. Its unique crystal shape is created by individual molecules of sugar.

Follow this easy guide inspired by The Spruce Eats to make your own rock candy that’s delicious and eye catching. It’s easy to double or triple the recipe based on how much candy you’d like to make. The process takes about a week, so be sure to plan ahead if you’re gifting.



  1. Cut a piece of thread a few inches longer than the mason jar.
  2. Tape or tie the thread to a pencil or skewer.
  3. Wet the thread with water, and then coat it with granulated sugar. Set aside to dry.
  4. In a medium pan, bring 2 cups of water to a boil. Add sugar one cup at a time. Stir while adding.
  5. Continue to stir until all the sugar is dissolved, and then remove pan from heat.
  6. Stir food coloring or flavor extracts into the sugar solution, if desired.
  7. Allow the sugar solution to cool for about 10 minutes, and then carefully pour it into the mason jar.
  8. Lower the sugared thread into the jar, balancing the pencil or skewer on the rim. The thread should fall about 1 inch from the bottom of the jar.
  9. Move the jar to a cool, dry place where it can stay for about 7 days. To protect your developing rock candy, cover the top of the jar with a paper towel or plastic wrap.
  10. Check the jar in a few hours. You should start to be able to see crystals forming on the thread.
  11. Carefully remove the string after about a week, or whenever the crystals are as large as you’d like them to be.
  12. Enjoy!


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