Rock candy, a popular candy in stores around the world, has a variety of interesting characteristics, including its origin, the process to create it and the science behind its appearance.


According to rock candy manufacturer, Dryden and Palmer, rock candy is referenced in both Indian and Iranian writings from the 9th century. This indicates that rock candy has been around for over a thousand years and probably was invented in the eastern part of the world.


Before becoming a popular sweet, rock candy was used as a medicine. According to Candy Warehouse, rock candy is referenced as a medicine for the throat by Shakespeare in his play titled “Henry IV.”

Making Rock Candy

Making rock candy doesn’t require many ingredients; only sugar and water, but it takes a lot of patience, as it can take up to a week for the candy to grow. It is made by boiling sugar water, and then suspending a sugar coated string into the solution, leaving it undisturbed until the rock candy has grown. For variety, food coloring or flavoring may be added.


Rock candy is essentially sugar crystals grown to create large sugar crystal formations. Growing rock candy is an easy way to learn more about crystals and demonstrate how they are formed.