For a unique learning experience in basic chemistry, kids can be encouraged to grow their own rock candy crystals, even color them, and eat the result.

Rock crystals are one of the earliest forms of candy. You see rock candy on a stick offered even today at candy counters. Our experiment will use string instead of a stick.

The project is not difficult at all and will take up to seven days to complete. A little adult supervision early in the procedure is advisable (you need to handle some boiling water briefly). Most of the rest of the time involves simple observation, no handling or touching. Materials needed are minimal.

Preparation

You will need four cups of sugar, two cups of water, a pencil, something to act as a weight such as a screw, washer, or a paper clip, and a piece of string. Everything needs to be ultra-clean.

Getting Started

Under adult supervision, bring the water to boil in a saucepan.

The sugar then needs to be added to the water. Stir until sugar is dissolved. You can add food coloring or flavoring at this stage should you wish.

Remove from heat, pour carefully into a small jar of clear glass. The heat can cause it to crack, so when you pour in a bit, swirl it around in the jar before adding more. A jar such as used in canning is best because it can handle heat better, but be careful.

Cover the mouth of the jar with a piece of wax paper.

Second Step

Attach your weight to one end of the string. Tie the other end to the center of a pencil which will be laying across the top of the jar when you are done.

Suspend the string into the water, until the pencil is laying flat. The weight should not be touching the bottom of the jar, so make certain your string is short enough. After a few minutes, remove the string from the water and lay it across the waxed paper so it can dry out. In the process of drying, tiny crystals will begin forming which will be the basis for the finished crystals.

Final Step

Now, return the string to the sugar solution. Leave it untouched for about seven days. Don’t add any water to replace any that might evaporates. Hands off.

You will be able to watch the crystals grow. And when they’re done, enjoy!