Library Blog

Rock Candy DIY

Rock Candy

Do you have a sweet tooth? Are you looking for a DIY project that will be fun for the entire family? Why not do something that satisfies both requirements? For a fun activity that is part science activity and part sweet treat, why not try your hand at making rock candy? If you are not familiar with this type of candy, you might think of something that does not sound too appealing. It gets its name, however, from the way the candy is formed, like rock crystals. You will grow candied crystals that you can add flavoring and color to, and then eat when the project is complete. You only need to gather up some household ingredients, clear a space to work, and get started! The first steps of the process do not take terribly long to make at all, but there is some waiting required for the final product. That is part of the fun, though! Everyone can watch the crystals grow over the course of a few days to a week, and then at the end, there will be a delicious reward! 


The supplies needed for this project are: 

5 cups of sugar 

2 cups of water 

2 clean 16 oz. jars (mason jars work great) 

Food coloring 

Flavoring extract  

Spoon for stirring (wooden works great) 

Medium sized cooking pot 


2 bamboo skewers 

4 spring-hinge clothes pins 

Measuring cups 



Cut the skewers to the height of the jars. Then, wet the skewers, but make sure to leave the top 1 ½ inches dry on one end of each skewer. Then while over the plate, spoon some of the sugar onto the damp skewers, turning to coat them evenly. Once they are coated, set them aside to dry completely. 

Add the two cups of water to the pot. Place on the stove and turn to medium/high heat. Slowly begin to pour the five cups of sugar into the water and stir continuously until dissolved. Once most of the sugar has been added, the mixture will become thicker and cloudy as the sugar breaks down. Then, once the mixture comes to a steady simmer, add in 2-3 drops of any desired flavoring (extracts, such as lemon, etc.) as well as 2-3 drops of desired food coloring. Wait for the mixture to come to a low boil once more before removing from the heat.  

Let the rock candy mixture cool down quite a bit in the pot before pouring it into the two mason jars. Then leave on the counter to cool completely. Once completely cool, place one of the dry sugary skewers into the center of the mixture with the uncoated 1 ½ inch end sticking out of the jar.  You can use a clothes pin to secure the skewer in place by closing it around the skewer at the uncoated portion and then rest the edges of the clothes pin along the top of the jar, keeping the skewer in the center of the liquid. 

Leave the jars on the countertop with a paper towel draped over the clothes pins and check on your rock candy creations each day for one week. You should notice crystals forming after just one day! 


For full details and pictures of this activity, check out this link from the Orlando Science Center. 

DIY Candy Rocks! 


Romie is a Systemwide Floating Librarian at the Public Library of Youngstown and Mahoning County, where she has recently landed in the Technical Services Department. She loves to help people and learn new things every day. When not at work, she loves reading, going on adventures, and the great outdoors.