How to Make Rock Candy

Rock candy is a deliciously fun way to learn about how yummy science can be while exploring concepts such as evaporation and crystal formation. All you need to make this delicious treat are a few common household items and an adult to help. While the crystals do form slowly over the course of a week, with a little patience, you can watch closely as these amazing “rock” formations take shape. Rock candy is easy to make at home or at school and is a favorite with kids of all ages. Add in some unique flavors and colors and you have a recipe for a tasty science experiment that is as fun to make as it is to eat!

What You Will Need

Before you can start making these delicious candies, you first need to gather all of your materials together, including any flavoring or food coloring you wish to add. While food coloring and flavorings are optional, they can be a fun way to customize your candy just the way you like it. Here’s a list of everything you will need to make these yummy treats.

  • A wooden skewer or chopstick
  • A clothespin
  • A tall, narrow glass or jar
  • 1 cup of water
  • 2-3 cups of sugar
  • Optional: ½ tsp to 1 tsp of flavor extract or oil
  • Optional: 2 or more drops of food coloring

How to Make It

Once you have gathered everything you need to get started, all that’s left to do is to find an adult to help with some of the more dangerous steps. To make these delicious candy science experiments, you will need a grownup to help with that parts that require hot liquids or using the stove. Remember, safety first! To make rock candy, here’s what you need to do:

  1. Use the clothespin to clip the wooden skewer so that it hangs down inside your glass. You will need to make sure you keep it about 1 inch from the bottom. Once you’ve got the clothespin clipped in the right spot, you can pull the skewer and clothespin out and put it aside until later.
  2. Have your adult helper pour the water into a pan. Heat the water on high until it begins to boil.
  3. Next, begin pouring sugar into the boiling water about a quarter-cup at a time, allowing the sugar to dissolve completely each time before adding more sugar. Keep adding sugar until it will no longer dissolve.
  4. Once your solution is ready, have your adult helper remove the hot liquid from the heat, setting it aside to cool. Once you have removed your solution from the heat, you can add your food coloring and flavoring and mix it in. Now is the time to get creative! When you’re done, let it cool for at least 20 minutes.
  5. Once your sugar solution has cooled, it’s time to carefully pour it into your prepared jar or glass. Then, you can submerge your prepared skewer, keeping it in the middle so it doesn’t touch the sides.
  6. Now, find a place to put your jars where it won’t be moved or disturbed. Make sure to pick a spot where you’ll still be able to keep an eye on it to watch your candy grow!
  7. Wait and be patient. It will take from three to seven days for the candy to form.

How Does it Work?

Rock candy crystal sticks are made by dissolving sugar in water until the water can’t hold any more sugar. Heating the water to the boiling point increases the amount of sugar it can hold. Once the water begins to cool, it can’t hold as much sugar anymore, so some of the sugar clumps into crystals, sticking to any surface it can find. By submerging the skewer in the jar, you give the sugar crystals something to cling onto and continue to grow on. With patience, you can watch as the sugar begins to form crystals, eventually growing as big as some of the ones people can find nature. Once your crystal candy has gotten as big as you want it or as big as it can, it’s time for the best part of this experiment. It’s finally time to eat and enjoy your creation!

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