How To Make Rock Candy or Sugar Crystals

Rock Candy or Sugar Crystals

Sugar crystals are one of the few types of crystals you can grow that you can eat. (Anne Helmenstine)

Sugar crystals are called rock candy because these hard crystals are edible. Sugar (sucrose) crystals are one of the few types of crystals you can grow and eat. You can eat the natural clear crystals or you can color and flavor them.

Rock Candy Materials

  • 3 cups sugar (sucrose)
  • 1 cup boiling water
  • food coloring (optional)
  • flavoring (optional — good choices include cherry, peppermint, and cinnamon)
  • clean glass or plastic jar
  • wooden skewer or cotton string

Grow Sugar Crystals

The procedure is really easy.

  1. Dissolve the sugar in the boiling water. You can heat the sugar solution on the stove or in the microwave if you have trouble getting the sugar to dissolve.
  2. Add a few drops of food coloring and flavor, if desired.
  3. Allow the solution to cool a bit before pouring it into your jar. You don’t want to get burned!
  4. Pour the sugar solution into a jar. Place a wooden skewer into the jar or else hang a string into the middle of the jar, tied to a pencil or butter knife.
  5. Place the container somewhere it won’t be disturbed. You may wish to cover the jar with a paper towel or coffee filter to allow evaporation while keeping the crystal solution clean.
  6. It may take a few days to get good crystal growth. If you see crystals forming on the top of the jar, you can remove them and eat them. If you leave them, these crystals will compete with your stick or string for sugar and will reduce the size of your crystals.
  7. Remove the crystals and enjoy them! If you want to store the crystals before eating them, keep them in an airtight container so humidity in the air won’t make the rock candy sticky.
How To Make Rock Candy or Sugar Crystals
Last modified: August 18th, 2015 by Anne Helmenstine

10 thoughts on “How To Make Rock Candy or Sugar Crystals

  1. Pingback: Green Rock Candy - As I See It

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    1. Anne Helmenstine Post author

      You can add it afterward, but the solution thickens quickly, so it’s a bit easier to mix in flavor and color when it’s hot. It’s up to you. If you want to use one solution to make multiple colors and flavors, by all means, add it later 🙂

  3. #yassQueenSlay

    I found this very usefull for granulated sugar, but will powdered, brown, caster, and sanding sugar work?

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