Want something fun and educational to do with your curious kiddos? Homemade Rock Candy is easy to make and doubles as a fun science experiment AND an edible sweet treat!
This experiment does take some time and patience – but the wait is absolutely worth it! It is amazing to see how some colored sugar water can transform and crystallize into beautiful, colorful rock candy over a period of just five days. Your kids will enjoy checking on the crystals daily to see how they gradually “grow” onto the lollipop sticks, and the reward at the end is the yummy treat!
Tools and Materials:
Ingredients for the Sugar Solution:
- 1 cup water, plus extra for seeding the sticks
- 3 cups sugar, plus extra for seeding the sticks
- Food coloring (I used gel for deeper colors)
- Flavor extract, if desired
Dip wooden sticks into water and then roll in sugar. Be sure to only add sugar where you want the candy to grow on the stick. This step allows the stick to “seed” the sugar crystals. Place on a flat surface to dry.
Add sugar and water into a large pot. Our pot was a 5-quart stainless steel Dutch oven.
Stir the sugar water constantly, bringing to a boil over medium heat. Add food coloring of choice and flavor, if desired. Stir well and remove from heat immediately.
Allow for the solution to rest for 20 minutes.
Pour the solution into a mason jar.
Place a popsicle stick over the mouth of the jar.
Submerge the seeded part of your wooden lollipop stick into the mason jar, leaving at least 1 inch between the bottom of the stick and the bottom of the jar.
Clamp a clothespin on to the wooden lollipop stick and place it into the sugar solution with the seeded side down.
Ensure the jar is placed in a clean location where it can stay undisturbed for 5 days.
If you want to check the growth on the sugar crystals, use a flashlight to shine through the jars. If you notice that crystals are growing on the sides of the jar, it may be because the jar was not thoroughly cleaned before the process.
If you notice a thick sugar layer growing over the top of the solution, this is okay. It is to be expected during the process and should be left undisturbed until the candy is ready to be removed.
When the candy is ready to be removed (ie.: the 5th day), use a spoon to crack the sugar crust and pull it away from the stick.
Carefully lift the candy from the mason jar and transfer to a clean, empty jar to dry.
It is possible that the candy has attached itself to the sides of the jar. Use a knife to gently chip away at the sides if this is the case.
If the candy is attached to the bottom, chances are high that you will not be able to remove the candy from the jar. (See our pink candy photo.)
Tips & Notes:
For every four sticks of candy, we had one complete failure and one misshapen candy.
We prefer using wide mouth and deep jars (about quart-size). It makes the candy-making process a lot easier.
Beware of jars with thin glass – they may crack when the hot sugar solution is added due to the sudden temperature change. If you’re using jars that have thin glass, we recommend heating the jars first by placing them under hot running water.
For each color, use 1 cup of water and 3 cups of sugar – these measurements allow for enough solution to cover each stick completely.
Be sure to wash your pot thoroughly between batches. If there is any leftover sugar from a previous batch, it will change your new sugar solution.
Avoid using paper lollipop sticks as they can swell and mold. We used rock candy sticks from Amazon (linked above.)
Ensure that your mason jars are perfectly clean with smooth inner walls because sugar crystals will cling on to anything.
Flavorings and extracts with color will change the color of the final product. If you want consistency in your colors, then we recommend only using clear extracts.
Allow the crystals to grow undisturbed. Even cracking the crystals on top of the solution can change the final rock candy. Once you place the sticks in the solution, do not remove them until you are sure you are done.