Stir sugar and water and bring to a full boil. Add food color if desired. Remove from heat and using a ladle, remove about 1/2 cup of syrup and pour carefully in a coffee mug. (This small amount will quickly cool and will be needed to prepare the skewers). Cover large amount of syrup with plastic food wrap and leave undisturbed until completely cold. This will take at least 4 hours or overnight.
Once syrup in coffee mug has cooled, dip about 15 bamboo skewers one inch deep into syrup and roll dipped part in granulated sugar. Place on a plastic food wrap lined cookie sheet and allow to dry for one day.
Stick non-sugared end of bamboo skewers about 1 inch apart in a piece of styrofoam. Turn styrofoam piece upside down and place above pan containing sugar syrup. The sugar coated end of skewers should now be into syrup. (Adjust height of styrofoam piece by sticking skewers in side and resting on edge of the pan)
Place in an area where crystals can grow without having to move container. (Moving will make crystals grow on sides of the pan). Allow about 7 days for crystals to grow.
Remove skewers from syrup and allow to dry for one day.
Properly wrapped rock candy will last for at least a year. The remaining syrup can be reused for another batch of rock candy.