Rock Candy - How to Make Rock Candy and Learn Science

Rock candy is fun to make. You can create these beautiful crystals with simple ingredients and a few pieces of everyday kitchen equipment.

The making of rock candy is an amusing way to introduce children to chemistry.

The sugar crystals created in the making of rock candy are monoclinic crystals. The shape of the crystal is dictated by the shape of the individual molecules so that the larger crystal shape - the rock candy - is the same shape of the smaller sugar crystal.

A monoclinic crystal is created on a 3D grid where the vectors go off in different directions. Two pairs of vectors are perpendicular and a third pair make an angle other than the first two.

Medium Saucepan

Wooden Spoon

Water

Sugar

Coloring Agent (if desired)

String - Natural Fiber or Heavy Cotton Thread

Tall Glass or Plastic Container

Pencil or Skewer

Tape

If young children participate in the making of rock candy, an adult should boil the syrup for safety sake. Since the syrup must be cool before pouring, children can do this, as well the the measuring before hand.

• Thoroughly wash all equipment and dry.

• Boil 2 cups of water and 4 cups of sugar until the sugar is dissolved.

• Allow sugar syrup to cool.

• Pour into containers.

• Add flavoring agent if desired (1 teaspoon of extract - vanilla, orange, almond, etc) or 1/2 teaspoon of flavoring oil (less if it's peppermint).

• Cut string or thread to a size long enough to wrap around a pencil or skewer, short enough so that it will not touch the bottom of the glass.

• Prime the string. Attach a weigh (paper clip). Dip in cooled sugar syrup. Lay the string or thread out straight on a nonstick cookie sheet or waxed paper. Allow to dry.

• Suspend primed string in sugar syrup. You will no longer need the weight.Wrap the string around a pencil to keep it in place. You can tape the string to the pencil and tape the pencil to the glass to avoid slippage.
  

• You can use skewers instead of string. Suspend skewer from the rim of the glass, anchoring it with clothespins.

• Set glasses on a level surface. Do not disturb the containers for 3 weeks.