Homemade Rock Candy is awesome! It really is food science working at its finest. Not only is it a fun experiment to do but the end result is so tasty.
Using just a few ingredients you can make rock candy at home. It would make a great activity to do with the kids as well. Maybe someone needs to conduct a science experiment for school? This would work perfectly for that. It is easy to do, if I can do it, you can do it. Let’s get started!
Step 1: Gather the ingredients and tools
Homemade rock candy only requires a few ingredients. You will need:
- Water – I generally use filtered water, since my tap water tastes gross.
- White granulated sugar – The sugar is the star of the dish. You can’t make rock candy without the sugar.
- Food coloring – This is an optional ingredient. It is great for making all kinds of different colors.
- Flavoring – There are a variety of flavorings that you can put in your rocky candy.
- Wooden spoon or spatula
- Lollipop sticks or bamboo skewers
- Wide glasses or mason jars
Step 2: How to make homemade rock candy
To begin you need something for the rock candy crystals to form on. I generally use cake pop or lollipop sticks, strings are used frequently. I have also used bamboo skewers as well.
Dip the stick in water and then roll it in a plate that has some white granulated sugar on it. Little sugar crystals will stick to the stick. These are what are called “seed crystals.” The other crystals will attach themselves to these. Once the sticks are coated allow them to dry for 25 to 30 to minutes.
Step 3: Create the sugar solution
Time to make the sugar solution. Take a medium saucepot and add in the water. Place it on the stovetop and turn the heat to medium.
Once the water starts to simmer add in one of the cups of sugar. After that sugar dissolves add in another cup and repeat with the last cup of sugar. Stir the mixture and bring it to a boil.
Once it comes to a boil add in the food coloring and any flavoring that you may have. Mix it in and then turn off the heat. Allow the hot sugar solution to cool for 20 minutes. This is the base solution for rock candy.
Note: Please do not touch the liquid or the pot it is extremely hot and will burn you. Young children should have adult supervision when making rock candy at home.
Step 4: Containers for the Rock Candy to grow in
Next, you need some sort of container to put the solution in. The container shouldn’t be too narrow it needs to be wide enough to allow the crystals to form without sticking to the sides. I generally use a large mason jar for my rock candy (800 ml size). That, size jar will make one large rock candy. Or can can try it with smaller containers.
Use a funnel so it is easier to fill up the jar. Leave about an inch to an inch to two inches of space from the top. Add a circular ring to the top of the jar and then dip one of your sugar sticks in it and attach it with a clothespin.
Make sure there is an inch and a half of space between the bottom of the jar/container and the stick. If you want to make a few different colors and flavors, don’t add the food coloring and flavoring while the solution is heating. You can add it to the individual jars instead.
Now it is time to wait for those sugar crystals to develop. This will usually take 5 to 7 days for a good amount of crystals to form making that awesome rock candy.
Step 5: Homemade Rock Candy has formed!
After a few days, you will be able to see the progress of rock candy. Notice the film of sugar that has grown on the very top surface of the sugar solution, this is normal. Time to remove the candy from the solution.
Use a fork and gently break apart the thin layer of sugar crystals on the top. Pull the stick with the rock candy out of the solution and place it on another glass to dry.
This will allow any dripping sugar water to be contained. Let them dry for about 4 hours. The longer you allow them to sit in the water the larger the crystals will grow. Don’t they look awesome?
Rock Candy Troubleshooting Tips
It is possible that so many crystals will grow in the glass or cup and the stick will get stuck. This glass is a little too narrow of a glass. This is science but not always an exact science, meaning sometimes the sugar crystals just don’t grow how you want them to.
I have found an 800 ml size mason jar works great, it is about 3.5 inches wide and 6.5 inches tall. But it will only make one large candy with this recipe. The cool thing is the science still worked.
Sugar crystals did form, just too well, because the stick won’t come out. Sometimes you can run hot water on the bottom of the glass to release the stick.
Why are my rock candy crystals so small?
Was your glass or container cold by chance? When pouring the hot liquid into the container it may have cooled quicker causing the development of smaller crystals. One way to avoid this is the heat the jar up on the outside with hot water before adding the sugar solution. Or just a metal container like a wide thermos.
How long can I store the rock candy?
Rock candy, if stored in a dry place, can last for up to a whole year.
Can I reuse the leftover liquid?
Yes, you can reuse the leftover sugar syrup. If you want to make more rock candy, just heat it up with an additional cup of sugar, to replace the sugar that grew on the previous stick.
How do I clean the mason jar or glass after growing the rock candy?
Sometimes when you make rock candy the whole bottom of the glass gets covered with crystals, and they seem to grow everywhere but on the stick, haha. It can be a little bit of a pain to clean the glass. I find running incredibly hot water in the glass for a few minutes will melt the sugar enough to get it out of the glass. If you use something like a plastic cup, you can just throw it out.
Homemade Rock Candy
- wooden spoon or spatula
- lollipop sticks or bamboo skewers
- wide glasses or mason jars (400 to 800ml) or wide metal thermos
- 1 cup of water 240 ml
- 3 cups of white granulated sugar 600 g
- 1 – 2 tsp flavoring
- Begin by dipping the sticks in water and then rolling them in sugar. A plate works well to hold the sugar. I only dip it where I want the sugar crystals to grow. Set the sticks aside and allow them to dry. These are the seed crystals that the other crystals will grow on.
- Add a large pot to the stovetop and set to medium heat. Pour in the water and bring it to a simmer. Then add in the sugar a cup at a time, stirring it to dissolve the sugar. Bring it to a boil. If you are only using one color and flavor you can add it in right when it boils.
- Remove the pot from the heat and allow the sugar solution to cool for 20 minutes.
- After 20 minutes run the tap water until it gets really hot, let the water run over the glass or mason jar to heat it up until really warm. Make sure to use a wide glass or mason jar like the 800ml kind if you want larger candies, but you will get fewer of them, with this amount of liquid you will get 1 large one. Smaller mason jars or glasses for smaller candies, but you will get more of them. 2 to 3 of them.Pour the hot sugar solution into the containers. If you are using a metal thermos no need to heat it up. If you want different colors now would be the time to add those colors and flavors.
- Attach a clothespin to a sugar stick and set it in the solution. If necessary use a metal ring on top of the mason jar so the clothespin can sit on it. Try and keep the stick in the very middle of the glass and at least 1.5 inches from the bottom. If it is too close to the bottom the crystals might fill up the bottom.
- Let the crystals form for 3 to 5 days. Use a fork and gently break away any thin layer of sugar that has formed on the surface of the solution. Then pull out the rock candy and place in another container to dry for 4 hours. That's it! Enjoy!
Do you like the recipe? Please give it a rating and comment down below, I really appreciate it. If you make it tag me on Instagram @inthekitchenwithmatt. Also, sign up for the newsletter so you won’t miss out on any of my new posts and recipes.
Here are a few more recipes you may like:
What are some of the flavorings that you can use? Will vanilla work?
Hi Olivia! Any hard candy flavorings will work. You can try vanilla. There are several online that you can try like these. https://amzn.to/3muFxFa
My son wants a geode cake for his birthday with purple crystals (for amethyst) , and to my surprise it’s rather hard finding purple rock candy so I decided to make it myself. Made some small test batches so I could hone in my color and flavor and two weeks later I have 4 jars with perfectly purple and flavored rock candy “brewing”. I also like the fact that I can scrap off the crystals from the sides of the far and use them too. Such an easy “recipe” and works perfectly.
That is so awesome, Angel! 🙂 I am glad you like the recipe and are having fun experimenting with it. 🙂
can you put multiple sticks in one jar? i need to make a large batch but aren’t sure if it will work
Hello, Laila! It really depends on how wide the container is, if it is really wide, then yes, if it is a mason jar, then no, the sticks will be much too close together. 🙂
Is my solution meant to be very thick ?
It will be fairly thick, but not super-duper thick. Watch the video, that will give you a good idea how it should look.
Matt, and idea why within an hour my hole cup turns rock solid ?
Hi Kristina! Did you check the troubleshooting tips in the post? How narrow was your cup? Also, it really is a science experiment as opposed to an exact recipe that works perfectly every single time. Did you heat up the cup first?
I heated the cup up for 5 minutes in the microwave and I also made sure my sticks weren’t hitting could I possibly not heated the mixture long enough ?
It’s very possible. What size was your cup? If it is too small in diameter that will affect things as well.
How many cups of sugar do I use for the mixture?
Hello! Make sure to scroll all the way down on the recipe to find the printable recipe with the measurements. 1 cup of water, 3 cups of sugar
My daughter did this and used glass cups (our “fancy” ones?) and she took out the candy, but the rest of is rock solid and we can’t get it out. I’ve tried hot water, but I’m afraid boiling water will break the cup. It’s so completely rock solid and on the bottoms of the cup. I can’t scrape it out. Any suggestion?
hi there, Dassie! Yes, just run the water as hot as it will go from the tap and just keep it flowing inside, eventually it will loosen it up and melt the sugar. 🙂
If I wanted to make clusters of rock candy instead of on a stick, do I just pour the solution in the mason jar and then let it sit for 5 days?
Hi there, Lia! No, you need it to grow on something. If you just put it in the jar, they will grow in the jar, but it is too hard to get it out haha. You could experiment with a couple of different things. Like using an old half-gallon milk carton, which may work, just make sure the liquid isn’t too hot when you pour it in. That way you could just cut the carton. I haven’t tried the carton, just giving you ideas 🙂 Or like those wax paper cups, like used for hot coffee.
Would this work great for a school project?
Hi! What kind of flavouring do you use? I saw the link but are there any alternatives?
Any flavored extracts will work. 🙂 Some of the common ones to find at the supermarket are orange extract, cherry, lemon, mint, etc. That link I shared gives a huge variety. You can also dissolve kool-aid in the sugar solution to color and flavor it.
I am looking forward to trying to make this but how much flavoring oil should I use for a batch?
Hi Patti! Use 1 to 2 teaspoons of flavoring. 🙂
I made the recipe with 1 cup of water to almost 3 cups of sugar – 1 teas at a time. When I poured the mixture in the jars it was thick – not clear! Help!
Hi Julie, how long did you heat it? Did you put food coloring in it? It sounds like you may not have heated it up enough.
I run a candy shop on Etsy, and I was interested in making rock candy resembling worm on a string, but I’m not quite sure how or if I can even do that. What do you think? And if I can, how do you think I should go about doing that?
mmm, I am not sure if you could get it to grow that way. The string would stay long and straight because of gravity. It wouldn’t be curved like a worm. You would need to use some kind of curved stick. A fun experiment for sure.
I made the sugar water mixture, and I put it in the Mason Jar. But, I’m waiting for the sugar on the stick to dry. How long would you say it takes for it to dry? ?
When you dip the stick in water and then roll it in sugar, it only takes 20 minutes or so to dry, at least in my house. It should be dry by the time the sugar liquid has cooled enough.
Hey Matt looks great. Can you reheat the sugar water after removing your finished rock candy and repeat the process?
Thank you, Vicki! You certainly can, but you will need to add another cup of sugar to it, to replace the sugar that grew on the previous rock candy 🙂
If I leave a stick in the sugar solution for a longer period of time will the crystal’s continue to grow larger and larger?
Can I reheat the sugar solution, add more sugar (or even just make more) then put the same stick with already formed crystals to continue growing more rock candy on that stick?
I have these ridiculously oversized jars and I want to make enough sugar solution to make ridiculously oversized rock candy, because why not right 🙂 , and I was considering multiple layers for multiple flavours on the one rock candy stick for a flavour mixture 🙂
Hello, Missy! Yes, the longer you leave them the more crystals will grow. You can reheat the leftover solution, but will need to add another cup of sugar, to replace the sugar that grew on the stick. I have never tried adding different layers, so that would definitely be a fun experiment. 🙂 Try it like this first, so you get the hang up of it, since it can be tricky at times since it is more of a science experiment than something like a pancake recipe which pretty much always turns out. Good luck and have fun! 🙂
Awesome recipe! Although when I am putting the sugar coated sticks into the sugar/water solution, all the sugar seems to fall off the stick. Why is this?
Thank you! The liquid still may be a little too warm, but it still may be okay. You can let it cool just a little longer, and reroll the stick in sugar. Make sure the sugar dries on the stick completely first before dipping it.
It might be a dumb question, but can you put two sticks in a jar , or does it have to be one stick per jar.
Hi there! No, you can only do one stick in the jar. Otherwise they would just grow together. 🙂 If you had a wide enough container though, you could do more than one. But it would have to be twice as wide as a mason jar. 🙂
Why does my solution turn to sugar instead of crystals?
It sounds like you measured the ingredients incorrectly. The sugar solution, should remain a liquid even after the crystals for on the stick, lick in the pictures and video? Did you watch the video as well? That might help if you haven’t watched it yet.
I tried this recently using several different sized of mason jar, just what I had empty. I prepped the lollypop sticks by wetting them and rolling them in sugar, but when I checked them after one day, the entire bottom of all three jars were completely overgrown with crystals, with very little on the stick. I didn’t expect much to be on the stick after one day, but the bottom inch or two of each jar was totally overgrown.
Hello! Yes, that can definitely happen Tegan, since really it is a food science expirement. Did you heat up the jar with hot water first? Sometimes that helps.