2 cups water
4 cups sugar
food coloring (optional)
Recipe
Place two cups of water into a saucepan. Add four cups of sugar and stir for a minute to get as much sugar as possible to dissolve. Place the saucepan on the stove and turn the heat to medium-high. Stir until the sugar is dissolved. Add food coloring, if desired. Stir. Take the saucepan off the heat. If you're using a Rubbermaid or Tupperware container you can pour the hot liquid directly into it. Otherwise let the liquid cool in the saucepan; then pour into your plastic container (DO NOT use a glass container!!!!). (Larger crystals grow if the solution cools slowly. So, if possible, place container in a warm spot.)
Crystals will form on the surface in a few days. Do not remove them; sink them to the bottom with a spoon. In 7 days or so the bottom of the plastic container will be covered with a thick layer of sugar crystals (rock candy). Turn the container over in the sink. Let the excess sugar solution drain completely. This takes about 2 hours. When the surface of the crystals is dry, push on the sides and bottom of the plastic bowl and the crystals will break into chunks. Put crystals onto wax paper and let them dry completely. The more they dry, the more they sparkle.