This is one science experiment we can get behind. 

By Melanie Fincher
September 01, 2020
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Don't write off making rock candy as just as a grade-school science experiment. Sure, it does make for a fun learning experience, but it also makes delicious, homemade candy that the whole family can help make. You can give them as gifts or keep them all to yourself. Learn step-by-step how to make rock candy — it requires patience but you're rewarded with a treat in the end. 

What Is Rock Candy? 

Rock candy is the result of a saturated solution of sugar and water. A saturated solution is one in which no more solute (in this case, sugar) can be dissolved in a given volume of the solvent (in this case, water). As the water cools, the molecules move about more slowly, forcing any sugar molecules to form back together as crystals. 

As the water begins to evaporate over the course of a few days, the solubility decreases, causing more rock candy to grow out of the solution. If this just makes your head hurt — I feel your pain. All you really need to know is you start with water and sugar (and maybe some food coloring) and you end up with candy. So all this thinking pays off in the end. 

How to Make Homemade Rock Candy Step-by-Step

Equipment: 

  • Wooden skewers ($10; Amazon)
  • Clothespins ($8; Amazon)
  • Tall jars or glasses ($39; Amazon)
  • Saucepan
  • Spoon

Ingredients: 

  • 1 cup water
  • 3 cups sugar (plus a little extra to roll the skewers in)
  • Optional: Food coloring
  • Optional: Extracts or flavoring oils 

Instructions: 

  1. Bring the water to a boil over medium heat.
  2. Add the sugar, one cup at a time, stirring throughout. Remove from heat once the sugar has dissolved. 
  3. Add 3-7 drops of food coloring and/or flavoring to the mixture if desired. Stir until smooth. 
  4. Allow the mixture to cool for 20 to 30 minutes. 
  5. While you wait, pour the remaining sugar on a plate. Carefully dip the wooden skewers in the sugar solution and roll in sugar to coat. Clip a clothespin horizontally to the top of each skewer. 
  6. Once the solution is completely cooled, fill each jar with the remaining solution. Submerge one prepared skewer in each jar, balancing the clothespin on the top of the jar so it stays put
  7. Gently cover the jars with plastic wrap to protect the solution from bugs or dust. 
  8. And now we wait! Watch your crystals grow over the next three to seven days. Remove the skewers when you're ready to enjoy. You may have to submerge the jar in warm water to help ease your rock candy out of the jar. 

Related: Browse our entire collection of Candy Recipes