Learn how to make rock candy with our simple step by step tutorial! This homemade sugar candy is SO PRETTY and it tastes amazing! Make this DIY rock candy recipe that’s part science experiment and part tasty treat.
It’s so fun for kids to make their own rock candy and watch the sugar crystals grow more and more every day. Choose your favourite colours and flavours and make homemade rock candy sticks in your own kitchen!
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Check out our How to Make Rock Candy video tutorial:
Looking for more fun recipes? Here’s a few of our favourites:
How to Make Rock Candy
- 16 oz mason jars (5 of them)
- Gather your ingredients and supplies.
- Cut a wooden skewer to about 7 inches long. Spray half of the skewer with water.(You can also dunk it in a glass of water or put it under the tap.)
- Sprinkle sugar over the wet part, rotating the skewer to cover it. Adding sugar to the skewers gives seed crystals for your rock candy to grow on.
- Repeat with 4 other skewers and then set them on a parchment lined tray to dry.
- Add gel food colouring to the end of a stir stick, then place the coloured stir stick in an empty mason jar. Repeat using stir sticks with different colours for each jar.You can also use regular food colouring. Simply add about 5 drops to the bottom of each jar.
- Bring the water to a boil in a large pot.
- Add 1 cup of the sugar.
- Stir until the sugar dissolves.
- Repeat this process with the remaining 9 cups of sugar.Add 1 cup, stir to dissolve, add 1 cup, etc. It will take longer to dissolve the more sugar you've added.
- Allow the syrup to simmer for about 5 - 10 minutes. This will thicken the syrup a bit and ensure that all the sugar has dissolved.
- Remove the pot from the heat (CAREFUL: it's heavy and very hot!) and stir in the candy flavouring oil.(You can also use flavouring extracts. For these, use at least 1 teaspoon.)
- Use a ladle or transfer the syrup to a measuring cup and pour it into the prepared jars with the stir sticks in them. We found it too heavy and difficult to pour right from the pot.
- Stir well with the stir stick, until the colours are fully combined with the syrup. Remove the stir sticks.
- Allow the syrup to cool for 20 - 30 minutes.You can't add the skewers right away, or the seed crystals on them might melt right off.
- Once the syrup has cooled down add the prepared skewers into the syrup. Make sure the bottom of each skewer is at least 1 inch above the bottom of the jar.Secure the skewers with a wooden clothespin and center them in the jar.
- Set the jars in a place they won't be disturbed, away from any heat source or direct sunlight. Once the syrup is completely cooled, loosely cover the top of the jar with plastic wrap.
- Allow the crystals to grow for 5 - 7 days. (Or longer - see more information below.)
- Once your rock candy has grown to the size you want, use a spoon - or fork - to crack the crystals that have grown on the surface of the syrup.
- Remove the rock candy from the jar. At this point it will be dripping sugar syrup.
- Hang your rock candy inside a clean glass or jar to allow the extra syrup to drip off.
- Wait between 30 minutes to 1 hour for the rock candy to fully dry.
- Remove the clothespins and your rock candy is ready to enjoy!
- If the rock candy grows too large it may connect with the crystals at the bottom of the jar. Make sure your skewer is at least 1 inch above the bottom of the jar, and remove the rock candy before it gets too big.
- You can also use lollipop sticks or popsicle sticks to grow your rock candy.
What is rock candy?
Rock candy is a candy that’s sometimes called “sugar candy”, probably because it’s entirely made up of sugar crystals! You can often buy rock candy in candy stores or old fashioned general stores.
Colour and flavouring is added to the candy, since on its own it just tastes like plain sugar. You can eat rock candy on its own as a candy, dissolve it in a hot drink, use it as a garnish for cocktails or mocktails, or as a decoration on a dessert.
How long does it take to make rock candy?
Count on waiting at least 5 days for your rock candy to grow, but you may want to keep them growing for 10 – 14 days depending on how big you want them.
The timing really seems to vary. We made a few batches and even following the exact same recipe, they still seemed to grow at different speeds.
Also keep in mind that the rock candy looks larger when it’s submerged in the syrup (so it will be a bit smaller once you remove it).
Read more below on what factors determine how the rock candy turns out.
How much sugar do I need for a rock candy recipe? What type of sugar works best?
It takes a lot of sugar to make the supersaturated syrup that rock candy grows in. You need 10 cups of sugar to make 5 pieces of rock candy, which works out to about 4.4 pounds (2 kg).
Plus you’ll need a bit of extra sugar for the skewers, so count on buying 2 bags of sugar if you don’t have any in the house.
Regular granulated sugar on its own is the best option for making rock candy, but you can also use a combination of granulated and cane sugar.
Why didn’t my rock candy grow properly?
Growing crystals is a time consuming and sometimes finicky process. (See our salt crystals post for another example!) You need just the right ratio of water to sugar in order for sugar crystals to form.
Too much sugar and the syrup becomes oversaturated and the whole jar will crystalize into a hard sugar paste. Not enough sugar, and the crystals won’t form at all, because the syrup isn’t supersaturated.
Crystal formation can also be affected by things like moving the jars around while the crystals are growing, or even by high humidity in the air. Humidity and heat slow the evaporation rate, making it take longer for the crystals to grow.
Basically, there are a lot of things that can go wrong, so don’t feel bad if your rock candy didn’t grow properly!
What type of jars are best for making rock candy sticks?
We used regular mouth 16 ounce (2 cup) mason jars, and they worked really well. On our first test batch we also used a honey jar that fit close to the same amount of liquid, but was far more narrow. This jar? Not a good idea.
Basically you need to use jars that aren’t too tall and skinny. You need a wider jar for the crystals to build up on the stick properly.
In regular mason jars the crystals also grow in the bottom of the jar. But if your skewer is high enough up, these crystals remain separate from the rock candy itself.
In a narrow jar, the crystals still build up, but there isn’t as wide a surface, so they grow up and connect with the rock candy, making it difficult to remove the rock candy — and even more difficult to clean the jar.
How can I clean the mason jars after removing my DIY rock candy?
When you make rock candy you’ll end up with a hard crystal build up on the bottom of the jar. But don’t panic, because the jars are actually really easy to clean!
Pour the syrup out of the jar, making sure to catch any large sugar crystals. You can let these dry on parchment paper and eat them as well!
Once you’ve removed any loose crystals from the jars, rinse them out with hot water. Then add some dish soap to the jar and pour boiling water on top of it, filling the jars.
The jars will be very hot at first, so be careful and don’t touch them for at least 15 minutes. Then use a fork to break up as many of the crystals on the bottom of the jar as possible.
If the jar is still hot, wear oven mitts to hold the jar and pour the crystals and water down the drain. Repeat with boiling water if there are stubborn crystals remaining, and then clean the jar with soap and water.
Learn how to make rock candy and enjoy this old fashioned, homemade candy. It’s so cool to watch the crystals grow, and with a little bit of patience you can enjoy a tasty snack that you made yourself. So cool!
Here’s even more fun recipe ideas:
Our book Low-Mess Crafts for Kids is loaded with 72 fun and simple craft ideas for kids! The projects are fun, easy and most importantly low-mess, so the clean up is simple!