How to Make Homemade Rock Candy

Prep: 15 mins
Cook: 30 mins
Crystal Form and Dry Time: 168 hrs
Total: 168 hrs 45 mins
Servings: 4 servings
Yield: 4 candies

Rock candy is easy to make at home, it tastes great, and it's a fun recipe to do with kids. Better yet, it doubles as a science experiment because you get to watch the sugar crystals grow. It's also an excellent opportunity to get creative in the kitchen because the color and flavoring combinations you can create are endless.

Sugar crystal rock candy, colored bright red and purple, on wooden skewers

The Spruce Eats

Is Making Rock Candy Hard?

This is one of the simplest sugar candies you can make, though it does require patience. All you need is sugar and water and a few basic materials you likely have around the house. Most of the steps involve making the sugar syrup and preparing the sticks and jars. While you should start to see changes within the first few hours, it may take three to seven days for the rock candy to form.

How Much Sugar Syrup Will I Need?

Keep in mind that the exact quantity of sugar syrup you will need depends on the size of the jars you're using and how many candies you want. For example, the recipe's measurements work for four 12-ounce jars or one quart-sized Mason jar. You can easily double or triple the recipe and make more rock candy at once.

Skewers, Sticks, or String

A wooden skewer or popsicle stick are both good options for rock candy. They're easy to work with and make removing the candy a little easier if it gets stuck to the bottom crystals. You can also use a cotton string, you'll need to tie it to a weight of some kind, so it doesn't float in the syrup. While a paper clip is a common solution for this, a hard candy with a hole in the middle (e.g., Life Savers) is a food-safe alternative that works just as well.

Glass or Plastic

Glass is recommended because it is a relatively nonporous material that will produce better crystals. Foam cups and some plastic cups are more porous and may attract the sugar crystals away from the skewer, which is where you want them to grow. Some people have had success with plastic cups, so it is worth experimenting with your options.

Granulated Sugar is Best

Regular white granulated sugar seems to be the best for making rock candy. In some informal experiments, people have found that it produces larger crystals than other types of sugar. It's also the least expensive option, which is an important consideration because you need a lot of sugar to make rock candy.

For Easier Clean-Up

The crystals will grow on the bottom and sides of the jar, and they're pretty tough to remove. Rather than discarding the glass jars, they can be cleaned and used again. Begin by dumping out all of the syrup and any loose sugar crystals. Fill the jars with hot, soapy water and place them in a pan with about 3 inches of water. Boil the water for 10 minutes (for safety, watch it carefully as you would when canning), then turn off the heat. Let the jars cool to the touch and use a fork to break up the sugar crystals. Discard the sugar and wash the jars as normal.

Tips for Perfect Rock Candy

  • Oils or extracts—You can use either oils or extracts for flavor. The 1/2 to 1 teaspoon measurements for flavoring extracts that are provided create a mild-flavored rock candy. If you'd like a more intense flavor, carefully taste test the syrup in the pan and add up to a 1/2 teaspoon extract or 1/4 teaspoon oil more to your liking.
  • Paste or gel—Select paste or gel food coloring to create richer colors than liquid options. Keep in mind that the color of the rock candy will be significantly paler than the syrup. If you'd like to create a deeper color, use more food coloring, preferably of the gel variety.
  • Successful crystal formation—Heat is an important factor in crystal formation. Don't forget to transfer the syrup to warm jars before it cools off too much.

"Growing sugar crystals is tricky business because there are so many variables, but this is a fun kitchen experiment. I found that the stick option was easier to work with than the strings, though crystal growth was the same for both. This is also a sticky project and cleanup is not the most enjoyable part." —Colleen Graham

How to Make Homemade Rock Candy Tester Image
A Note From Our Recipe Tester

Ingredients

  • 6 cups granulated sugar, more as needed

  • 2 cups water, more as needed

  • 2 to 3 drops food coloring, optional

  • 1/2 to 1 teaspoon flavoring oil or extract

Steps to Make It

  1. Gather the ingredients and materials. Aside from sugar, you'll need four 12-ounce Mason jars or one quart-sized Mason jar, wooden skewers or strings, and clothespins. For the smaller jars, you'll use one wooden skewer (or string) for each. You can suspend several skewers in the larger jar. You'll suspend skewers (or strings) in the jars using clothespins.

  2. Clean the jars thoroughly with hot water. Set aside.

  3. Generously sprinkle a flat, rimmed plate with granulated sugar. Dip each skewer halfway into a glass of water and roll it in the plate of sugar to coat. This base layer gives the sugar crystals something to grab when they start forming. Set these aside to dry while you prepare the sugar syrup.

  4. Place the 2 cups of water in a medium saucepan and bring it to a boil on medium-high heat. Add the 6 cups granulated sugar, 1 cup at a time, stirring to dissolve before adding the next cup. You'll notice that it takes longer for the sugar to dissolve after each cup is added. Continue to stir, boiling the syrup until all of the sugar has been added, and it's completely dissolved. Remove the pan from the heat.

  5. If you're using colors or flavorings, add 2 to 3 drops food coloring and stir it in to ensure an even, smooth color. Add only 1/2 teaspoon flavoring oil, or 1 teaspoon flavoring extract. Make sure you don’t stand right in front of the pan because the scent can be very strong as it rises in the steam.

  6. Allow the sugar syrup to cool for 20 to 30 minutes.

  7. Quick-rinse the prepped jars with hot water, then pour in the warm syrup.

  8. Lower 1 reserved sugared skewer into each jar of syrup, using the clothespins to suspend it over the mouth of the jar about 1 inch from the bottom.

  9. Carefully place your jar in a cool place, away from harsh lights, where it can sit undisturbed. Cover the top loosely with plastic wrap or a paper towel.

  10. You should start to see sugar crystals forming within 2 to 4 hours. If you see no change after 24 hours, try boiling the sugar syrup again and dissolve another cup of sugar into it. Then, pour it back into the jar and insert the skewer again.

  11. Allow the rock candy to grow until it is the size you want. Don’t let it grow too large; otherwise, it might start growing onto the sides of your jar and you won't be able to remove it easily.

  12. Note that a top layer of crystal will form. This is OK. Once the candy has reached the desired size, gently break that top layer of crystal up with a fork, then remove the candy.

  13. Transfer the rock candy to an empty jar or glass with the clothespin suspending it, and allow it to dry for 1 to 2 hours.

  14. Serve and enjoy, or wrap in plastic wrap to save for later.

Feeling Adventurous? Try This:

  • Raspberry extract with blue food coloring creates a fun and delicious blue raspberry rock candy.
  • Cinnamon oil with red food coloring is fun for the winter and a fantastic treat or gift for the holidays.
  • Peppermint extract with a blue-green food coloring combination is always a delight. Any other mint flavoring is great as well; wintergreen and spearmint extracts are readily available.
  • Banana oil with yellow food coloring is always a hit with kids.
  • Maple extract creates an old-fashioned rock candy that doesn't necessarily need any coloring.
  • Other options include star anise for the taste of black licorice (purple), tutti-frutti (orange or pink), green apple (green), buttered rum flavoring (orange), cherry (red), grape (purple), or any other fun flavoring you find. Pair these with different colors, and you will have a rainbow of flavorful rock candy to share.

How to Store

Store remaining rock candy skewers in a large mason jar or wrapped individually in plastic in a cool, dry place.

Nutrition Facts (per serving)
1164 Calories
0g Fat
300g Carbs
0g Protein
×
Nutrition Facts
Servings: 4
Amount per serving
Calories 1164
% Daily Value*
Total Fat 0g 0%
Saturated Fat 0g 0%
Cholesterol 0mg 0%
Sodium 8mg 0%
Total Carbohydrate 300g 109%
Dietary Fiber 0g 0%
Total Sugars 300g
Protein 0g
Vitamin C 0mg 0%
Calcium 7mg 1%
Iron 0mg 1%
Potassium 8mg 0%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)