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How to Make Your Own Rock Candy Kit

Rock candy kits provide an interesting science experiment for small children and interested adults. By using heat to create a supersaturated solution of sugar and water, you set the stage for sugar crystals to encrust and grow upon a string suspended in that solution. As the water cools and evaporates it can no longer retain all the sugar that was dissolved in it, so the sugar molecules accumulate on the suspended string. As long as the string remains undisturbed, it may develop a spectacular accretion of hard sugar crystals--rock candy.

Things You'll Need

Pencil
12-inch length of cotton string
Glass jar, clean, between 6 and 12 inches tall
Clean metal washer
Clothespin
4 to 6 cups white sugar

Instructions

- 1
  Gather the listed items--a pencil, 12 inches of cotton string, a clean, label-free glass jar that's between 6 and 12 inches tall, a clean metal washer and a clothespin. You may include 4 to 6 cups of white sugar with the kit, as this is necessary to make the rock candy, or simply make note on the instructions that whoever uses the kit will need to provide their own sugar. If you include the sugar, seal it in a zip-close plastic bag.
- 2
  Tie one end of the string to the middle of the pencil and the other end to the washer. Wind the string around the middle of the pencil until the washer is flush against the pencil. Clip the clothespin on the pencil around the string to keep it from unwinding and place the pencil, string, washer and clothespin in the jar together. If you've decided to include sugar, place the plastic baggie of sugar in a paper bag along with the jar as there won't be room for it in the jar.
- 3
  Print off or write out the following directions, fold the paper and slip it into the jar along with the other items:
  
  "Heat 2 cups of water to boiling in a saucepan on the stove. Pour 1/4 cup of white sugar into the boiling water and stir continuously until the sugar is completely dissolved. Continue adding sugar, 1/4 cup at a time, until no more sugar will dissolve--expect to use at least 4 cups of sugar. Remove the solution from heat and let cool.
  
  Pour the now-cooled solution into the glass jar, filling it to within an inch of the top. Place the pencil across the top of the jar and slowly unwind string from the pencil, lowering the washer into the jar until it's dangling in the sugar solution, a few inches off the bottom of the jar. Place a clothespin over the string where it's wrapped around the pencil to keep it from unwinding any further.
  
  Place the jar where you can check on it every day without having to disturb or move it. Monitor daily--crystals should grow within a week."

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