How to Grow Sugar Crystals on a String

A fun educational experiment, with a tasty reward to look forward to at the end, growing sugar crystals on a string can not only teach children about crystals and crystallisation, it also yields rock candy that students can enjoy as they learn.

In addition to using this technique as a science experiment, you can also use the same method for making rock candy strings to serve as a fun family activity, or use them as attractive gifts during the holiday season. The entire process takes a few days to complete, but the end result is well worth the effort.

Things Required:

– 4 cups sugar
– 2 cups water
– Measuring cup
– Pot
– Wooden spoon
– Glass jar
– Cotton string
– Screw or washer
– Pencil
– Waxed paper


  • 1

    Begin by placing a medium sized pot on to the stove, pouring in 2 cups of water, and bringing it up to a boil.

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  • 2

    Add in the four cups of sugar, and stir it in to the boiling water, until it dissolves. Then, proceed to take the pot off the heat, and pour this sugar mixture into the glass jar. Make sure the glass jar is completely clean.

  • 3

    Procure a cotton string, and tie one end around the middle of a pencil. Then, tie a clean washer or screw to the other end. Make sure the string is only long enough to dandle around 2/3 of the way into the glass jar.

  • 4

    Dip the string in to the sugar solution (screw end first), and soak it in the mixture for a while. Then, take it back out, and lay it out straight on to a piece of waxed paper.

  • 5

    Allow the soaked string to dry for around two days. Meanwhile, cover the glass jar containing the sugar solution with more waxed paper, and keep it aside as the string dries.

  • 6

    Finally, hang the string in the sugar solution by laying the pencil across the rim of the jar, so the string dangles down into the sugar solution. Place the jar in a safe place where it cannot be knocked over, and after 7 days, your sugar crystals on a string will be ready.

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