Homemade Rock Candy is awesome! It really is food science working at its finest. Not only is it a fun science 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 simple ingredients. You will need:
- Water – I generally use filtered water, since my tap water tastes gross.
- White granulated sugar – White 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. So you can make all one flavor or many different flavors of candy.
Tools
- Pot
- Wooden spoon or spatula
- Lollipop sticks, bamboo skewers, strings, popsicle sticks, etc.
- Wide glasses or mason jars
- Clothespins
NOTE: A candy thermometer is not needed to make this homemade rock candy recipe.
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. You can also try using a popsicle stick.
Dip the stick in water and then roll it into 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 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. You can use between medium heat and medium-high heat will work fine for this sugar mixture.
Once the water starts to simmer add in one of the cups of white sugar. After that sugar dissolves add in another cup and repeat with the last cup of sugar. In total, there will be 3 cups of sugar. Stir the mixture and bring it to a boil. There is no need to use a candy thermometer. We don’t have to get a specific temperature, just need to get it to a rolling boil.
Once it comes to a rolling boil add in drops of food coloring until you get the desired color and any hard candy flavoring oil that you may have. Mix it in and then turn off the heat.
Allow the hot sugar solution to cool for 20 minutes until it reaches about room temperature, if it is too hot the sugar on the rock candy sticks will just melt right off. This is the base solution for hard candy rock crystals.
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 DIY 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 for crystal growth without sticking to the sides.
I generally use a large mason jar or other glass jars for my rock candy (800 ml size). That size jar will make one large rock candy. Or can can try it with smaller containers. Honestly, all you need is some sort of empty jar to make this. I have even used clear plastic cups as well.
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 different flavors of candy, don’t add the food coloring and flavoring oil 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 and yes it will require a little bit of patience. Unfortunately, you just can’t rush food science. It takes as long as it takes which is usually 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? You just made your very own rock candy.
While this is an easy recipe it isn’t foolproof. It is a food science experiment so you are bound to run into a few issues the first few times you try it. Below are some common issues and how to solve them.
Rock Candy Troubleshooting Tips
It is possible that so many crystals will grow in the glass or cup up the sides of the jar 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 that 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.
Can I make rock candy with powdered sugar or brown sugar?
No powdered sugar will not work very well for making the candy. However, brown sugar will work. The very best thing to use is just plain old white granulated sugar.
Homemade Rock Candy
Equipment
- pot
- wooden spoon or spatula
- lollipop sticks or bamboo skewers
- wide glasses or mason jars (400 to 800ml) or wide metal thermos
- clothespins
Ingredients
- 1 cup of water 240 ml
- 3 cups of white granulated sugar 600 g
- 1 – 2 tsp flavoring
Instructions
- 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!
Video
Notes
Nutrition
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.
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I’m going to try this right now with my grandsons.
Good luck, Jan! Have fun. 🙂
I have everything but the clothespins. Any ideas on how to secure the sticks otherwise?
A little bit of tape will work. 🙂 Lay as stick across and then tape the other one to it, that is supposed to be in the container or sugar solution.
We did this experiment after growing crystals on pipe cleaners with borax and water; which turned out beautiful! I told my kids that we can do a similar experiment with sugar and it would be so fun to eat for a treat afterward. However, I was doing this with them when they should have already been in bed (confessions of a Mommy) so I was feeling rushed and exasperated.
I sure hope I didn’t ruin the candy…
1. I dipped my lollipop stick in water and sugar and let it dry.
2. Then I made the simple syrup.
3. While that was cooling, I used little plastic dixie-type cups, put a drop of LorAnn flavoring and a drop of gel coloring in each one.
4. After 25 minutes, I poured the hot syrup into a measuring cup with a spout to pour into my little cups.
5. I used my lollipop sticks to stir the color and flavor before propping them up with forks (couldn’t find my clothespins-go figure!)
6. All the ones with lemon oil spilled through the bottom of the cups; I have a feeling the acidity of the lemon oil vs. the other flavors ate through the bottom of the cup while we were waiting…some I caught in time and stacked into another cup, the others were a big mess on the counter.
7. Because of the big mess, I transferred all the cups to sit in a 1/2 sheet pan and moved the pan to a different surface.
In other words, I do not think I followed even one direction properly…any chance of them growing or should I just start over?
Hi Sara! Fun that you are trying them out. I really wouldn’t use plastic dixie cups, the sugar solution is just too hot. You need something like a mason jar or really wide glass. Even a metal thermos will work too. You can start again, or pour all of it back into a pot and reheat it. 🙂
The solution wasn’t too hot after it sat for 25 minutes; it didn’t melt or disfigure the cups or anything. The only ones that had a problem were the ones with the lemon oil and they were a problem mostly before I even put the hot liquid into them. If it won’t work because they don’t retain heat, that I would understand. I am not giving up on these yet; will let them sit and see what happens and if it doesn’t work, I will remelt them and make them on my own, when my kids are not around :).
Ahh, I see. Hopefully, the crystals do grow! It is a very fun experiment, can be finicky, but really awesome when they work. 🙂 Keep me updated on how they turn out. 🙂
Is it normal when you leave it to cool in the pot, crystals form?
Hi Lydia, yes, that is normal and crystals may start to form. Most of the time the reason why they form is there was a bit of sugar on the sides of the pot that didn’t melt. Sometimes, you need to use a damp basting brush and brush those down while the solution is heating up.
I am going to make my own rock candies following your directions above and am wanting to use 32 oz mason jars to grow my crystals in. For 1 batch of sugar solution (1 cup water, 3 cups sugar) how many jars will that fill? I am wanting to only make enough solution for one jar and am trying to figure that out.
Hi Roger, that will be enough for 1 jar. 🙂 The mason Jars I normally use are the 800 ml or around 24 oz. So a 32 oz will be a good size as well. It will hold all the solution for one batch. Good luck! Let me know how it goes. It is a fun experiment for sure.
When I let the syrup cool, it starts to crystalize on the top. Is that normal? What can I do to prevent it?
Hi Lydia, so sorry for the late reply! Yes that is normal for it to crystalize on top. After the rock candy grows, a lot of times you need to gently crack the top to get it out. How did it go?
When I left the syrup to cool, It formed crystals on top. Is that normal? How can I prevent it?
Yep, that is normal. Especially if using a narrower glass or container for the solution. I am pretty sure I show that in my video tutorial which you can find on the post as well. It is usually a thin film of sugar that forms across the whole top, that you gently break to pull the candy out. The only way to prevent it is to have a much wider glass or container, but that would require more solution/syrup.
When I let the syrup cool, It starts to form crystals on the top. Is that normal? How can I prevent it?
Hi Lydia, it is normal to have some crystals form on top, a lot of times it will form a thin top of crystals all the way across the top of the glass, then you gently break to pull the candy out. I think I show that in the video tutorial. The only way to prevent that is to have a really wide glass, which would require more candy solution.
This was amazing thank you so much for this helpful vid?
So glad it was helpful for you, Lyndall! 🙂
Will a string work as a substitute for a lollipop stick?
Hello! Others have been successful with a string. I always use the lollipop sticks or like a bamboo bbq skewer.
Hello!
It seems like our entire jar solidified after about an hour.
Any idea what we did wrong?
Thanks again for the recipe!
Hi there, Kirsten, since growing rock candy isn’t an exact science, and can be very finicky, there are several things that could have gone wrong. How wide is your jar? How far did you put the stick down, is it a stick or string that you used? Did you heat up the jar before adding the sugar solution? The good news is that you got crystals to grow! But it may take a little practice and experimenting to get it to grow exactly how you want it. Even I have had issues on occasion.
do you have any flavors that you would recommend for your first time doing these things? like vanilla or peppermint?
Hello, Marlee! Peppermint is good, any fruit flavors would be good.
Why did my sugar fall off when I put it the stick in the solution? I wanted two hrs for the stick to dry. Am I supposed to insert the stick 10 mins after boiling or do I let it cool and then place the stick? School project for my kids and I can’t get it to work. Please help.
Hi Katie, what do you mean, the seed sugar? It shouldn’t take 2 hours for the seed sugar to dry on the stick. Just lightly dip it in water then roll it in the sugar, it should be dry in less than 20 minutes or so. Also, you let it cool for longer than 10 minutes after it boils, it should be 20 minutes. Step 3 in the printed recipe. 🙂 Let me know if that helps.
Marlee, we some cotton candy flavored extract online. It’s a great flavor to have for many different things from rock candy to ice cream. Also, raspberry extract with blue coloring. Root beer turned out to be a big hit around our house. Banana wasn’t bad. Just about any flavoring extract works. Good luck
So many great flavors that you can get online.
So, I haven’t tried this yet, but I was wondering if popsicle sticks would work instead of lollipop sticks?
That is a good question, Grace, I think so, I haven’t tried it with popsicle sticks, so I can’t say for certain.
Grace, popsicle work just fine. We had the best looking ones when we used wooden BBQ skewers and cut the sharp end off. Cut to length of container and you’re ready. We also use what we but if leftover syrup to lightly coat the skewers and then roll them in sugar and let dry while the syrup cools. Gives you a massive head start for some larger crystals. Also, the container greatly affects the crystallization process. Best thing ever is the old metal coffee thermos that had the metal cap that could be used as a cup. But to answer your question….yes. Good luck!
Yes, those bamboo skewers work great too!
Hi Matt I wondered what would happen or if i could not use flavoring in my rock candy?
Hi Jenna, it would just be clear rock candy. 🙂 It will still work.
I was wondering if the solution needs to cover the stick completely? I only have the jar half full with solution.
Hi Amy, no the solution should only cover the stick about half way. 🙂
I messed up badly, but i forget to put the sea crystals on the stick, i was in a rush because my deaf little sister wanted to make it so i had to rush so hopefully something nice turns out ?
Yeah, unfortunately, you need to dip the stick in water and then roll it in the sugar, for the seed crystals. Not sure it will turn out. If not you can start again. 🙂 Let me know how it goes.
This was the first time I ever attempted any candy making.And I must say my kids loved making them as we nailed it on our first try with 6 pops.Next time we need to try flavors.Thank you
That is so awesome, Brian!! Especially because they can be finicky sometimes lol. So glad you nailed it. 🙂 You are very welcome.
This was perfect! After 2 failed attempts with other recipes we found your kitchen and 7 days later we have 4 sticks and 2 strings of candy, plus a bunch of pieces on the top and bottom!
That is awesome! I am so glad you tried it and were successful, Jes! 🙂 Food science is fun isn’t it? 🙂
I should note that we tripled the recipe to get 6 servings. But could probably add more sugar and reuse the solution. Also we found our wood worked better than the string. We used mint in green, vanilla in purple, and orange in orange. My son didn’t put very much dye in because he wanted to see the crystals growing. He’s ready to try again ?
That is so cool! 🙂 So glad he had fun making it. Such a fun experiment that you can eat! Yes, it takes quite a bit of sugar solution to make a nice piece of rock candy that doesn’t get stuck to the bottom, haha. And you can try reusing it, just heat it back up and add about a cup additional sugar to it. I think the stick works a little better as well than a string.
Hi, I was wondering if you had any tips for doing these in a larger batch? I want to do about 40 but I just cant imagine lining up 40 Mason jars lol
lol wow, that is a lot!! You could use a lot of wide deep pots. And then run a plat narrow board across that will rest on top of the pot. Which would have little holes drilled through them so the popsicle stick/bamboo skewer would fit through it. Then to make sure it doesn’t slide out, put a clothespin on the top of each one. Maybe a few of those cheap aluminum roasting pans would work. With that said I would experiment first with a small batch just to get the hang of it, it can be a little tricky, haha. Fun though! Let me know how it goes.
hi this is 11 year old catherine, i am very happy how it is so far, no crystals have formed. that’s also because it has only been sitting there for i think about 3 hours, so hopefully it will still grow!!! i will write another comment once some form. i do recommend it so far!!! i do also like the video it was helpful!! thank you matt!
Hello Catherine, yes it will take a few days and up to 7 full days to develop nice big crystals. 🙂 Let me know how it goes. 🙂
Hello i am waiting for my crystals to grow and why does it look like there is already a lot of crystals?
Hello, Amelia, if the crystals are forming super fast it could mean the jar wasn’t heated up. Did you heat up your jar with hot water first? Are the crystals growing on the stick/string, or are they growing on the bottom of the glass really quickly?
The numbers on this recipe really need a re-work. It says it yields 6 candies, but we doubled your recipe and didn’t even have enough of the syrup to fill 3 of the 800 ml mason jars to halfway.
Yeah, they might be off, I will have to double-check, I made the YouTube video long before I converted it to a recipe for the blog. But did they actually turn out? And I haven’t made them recently.
But yes you can get 5 to 6 if you use smaller containers, you just need to make sure the sticks aren’t too close to the bottom of the container. The candies will, of course, be smaller as well. You don’t have to use the 800ml mason jars, that is just what I like to use. To get 5 or 6 of the larger ones, you will need more for sure though. I edited the recipe a bit to better reflect the amount used. I also, mention reusing the liquid to get more candies out of it. 🙂