Instructables

Grow Your Own Rock Candy

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Looking for something sugary to satisfy your sweet tooth, and at the same time have something fun to fill your time?  Then try growing your own rock candy!  Often times seen at carnivals, fairs, or theme parks, this sucker will not only taste great, but you'll learn something in the process as well.  Once you try it, and you decide you want to branch out, try some new flavors!  It does take 3 to 5 days to grow, but the end result is a delicious treat that you can impress your friends with!
 
 
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Step 1: Ingredients

Picture of Ingredients
I guarantee you have all the ingredients needed to grow your own rock candy at your home already.  If you decide to get a little more experimental, you may want to take a trip to your local grocery store, they'll have everything you need!

Ingredients
1 Cup of Water

3 Cups of Sugar (not powdered, but then again I haven't tried it.)

1 Wooden Skewer (also known as a brochette in the cooking world.)
       If you don't have one, a piece of string and a paper clip will work.

1 Clothespin (I needed two because my glass had a wider rim than I expected)
       If you don't have a clothespin, a paper clip will work.  Or if you're using a string then a          toothpick would work.

1 Pan or Pot, and a stove

Fork or Wooden Spoon

1 Tall glass (A regular dinner glass will work, but do not use plastic or paper)

Those are all the ingredients you really need.  I used some other things as well, but that is because I had done it once before and wanted to try some new things.

1 Cookie sheet

2 Tablespoons of Vanilla

Aluminium Foil
punkyc11 month ago

when did you make this?

mhettick4 months ago
thanks i needed a rock candy recipe!
Vininski8 months ago
I mustn't have boiled it for long enough or something cause mine took a few weeks to grow a decent amount (I also realised after that a metal skewer was not the best choice). Anyway worked a treat, thanks very much!
Saturn V3 years ago
Mine isn't growing on the skewer, it's recrystallizing on the top. Why is this? The skewer was straight down the middle, 1 inch from the bottom.
JBarker09 (author)  Saturn V3 years ago
I've noticed with mine if they start growing on top, it won't grow on the stick. If i take a fork or something and poke the surface so the liquid is exposed again it started growing. I have no explanation for this, but I hope to find out the answer in my fluid mechanics class this semester at Arizona State.
Pull out the stick and reheat the solution. The crystals on top will go back into the solution and then you can put the stick back in and continue. Once crystals form new crystals will want to connect with them. If you only allow crystals on the stick, that's the only place they will grow.
Ah. Now some is finally growing on the stick, but it's just a very tiny bit. Some of it's even growing on the glass. Darn variables!
decant it into a new glass when it grows in the side
you can break it up and eat the crystals
Galahir9501 year ago
How much "Pure Lemon Extract" and "Maple Extract" would this recipe need? The 2 flavors would make seperate candies.
Love how you put some science into this! Very interesting!
Momarabbit2 years ago
Anyone have an idea how to make several at a time for a kids birthday party. If I follow above i would have to use a LOT of glasses. I can't think of how to go about this. Thank you in advance!
JBarker09 (author)  Momarabbit2 years ago
The only thing I could think of would be to use a container such as one used to store cereal that is an oval shaped, taller container. I would say anything that is able to keep them a reasonable distance apart, and that won't melt when you pour the liquid in would work. And when I say reasonable distance, I would think a little more than the diameter of the candy you are making would suffice. Never tried it though. Hope this helped!
Collarina3 years ago
This only make one?
Obediah3 years ago
It would only take a a little bit of effort to give the powdered suger version a test. Maybe it would work, maybe not. Failure is ALWAYS an option. Either way you learn something.
Are you a Mythbusters fan?
i am
definitely, it just seems that everyone is assuming that powdered sugar has starch, and that would make it impossible to grow rock candy. MB has taught me never to take public opinion as wise. $3 and 20 minutes of work and you have your answer, maybe you have something totally better.
BUBBA RAY3 years ago
this is a great project me and the family were doing it right now as i speak great idea
Shany1203 years ago
yummy!!!
build523 years ago
sweet!!!!! I can't wait to make it.
Instead of skewers, I use chopsticks.
BoogieWipes3 years ago
Nice Instructable I am going to make these some time.
Sagi3 years ago
I like those for tea! In German tea stores you can buy ready-made baskets with some tea, a nice cup and some sugar sticks. Its a nice thing if you can make something like this all by yourself!
mark_taner3 years ago
try arenga palm (liquid) sugar ..... hmmm...
mattbomb3 years ago
were and what kind of flavoring can i use. and were can i find it
ive had mine out for over 2 weeks and nothing has happened
JBarker09 (author)  Jimmy Proton3 years ago
There are a number of things that could have happened. I've found that adding too much flavoring (at least of the vanilla), will stunt the crystal growth. Also, if there is not enough sugar, the crystal will not grow. It has to reach the point of supersaturation. Also I have found that skewers with a smoother surface will not grow as well either. The sugar needs something "rough" or grainy to grow onto. This can be solved by "seeding" the skewer by coating it in some of the solution and then rolling it in sugar. If this is done, it has to cool before you put it into the glass so the sugar does not fall off and float to the bottom. I've done this on half a dozen separate occasions, and it has worked every time. The longest I've had to wait is three weeks, because I wanted to see if the crystal would still grow with all the added vanilla. eventually it did grow, but I had to break the seal that had formed on the top of the liquid. Hopefully this helps.
i didnt use any flavoring, i put as much sugar as i could, and i am using thick twine for it to grow on, ive noticed that the liquid is very thick and gooey, like the waters evaporating and leaving behind the sugar but it wont grow..nothing. maybe if i take the twine out and let the sugar thats soaked into it dry and harden then put that in there it mite grow
JBarker09 (author)  Jimmy Proton3 years ago
I just thought of something else that could make a difference. I'm not sure what I used, but it could effect the results if using either distilled water or filtered water.
i think i used sink water, maybe thats it
HollyHarken3 years ago
For flavoring try LorAn oils. Add them in after the boiling process. It would probably be best to add any flavoring including vanilla at that time. Otherwise you boil off the flavor! LorAn oils are made especially for candy making and can be bought in some craft stores depending on where you live. I buy mine through a local party supply store that carries cake decorating supplies. If you use the oils only use a drop or two as they are concentrated. Food coloring will work to color the candy. Put it in after the boiling process as well.
JBarker09 (author)  HollyHarken3 years ago
My friend uses those to make homemade suckers. I'll definitely try adding the flavor after boiling. I didn't even think about that! Thanks.
JBarker09 (author) 3 years ago
For some reason my comments are posting in strange places, so if you see a comment that is out of place or doesn't have anything to do with what you posted, let me know and I'll delete it. I'm trying to post them in the right places but it's acting weird. My apologies.
joemonkey3 years ago
i always used Ammonia and Bleach. that makes the coolest colors.
just kidding. don't do that :)
JBarker09 (author)  joemonkey3 years ago
Gotta admit, I laughed pretty hard at this.
Schober3 years ago
Technically speaking powdered sugar should still work. Because powdered sugar is simply regular sugar crystals broken down to one tenth of their original size, and the crystaline form of a mineral remains the same no matter the size; so the cryatals should form the same way on the skewer. As for the dissolving it should actually dissolve better than regular sugar because the crystals are so much smaller but, the sugar may end up clumping together so I would recommend sifting the sugar into the boiling water. You may end up needing less of the powdered sugar due to the fact that there is less air between the crystals. Then again, these are just my semi-educated guesses and have not been tested.
trmpt99 Schober3 years ago
Actually, I would not use powdered sugar, since most powdered sugar includes starches to help alleviate moisture issues.
Schober trmpt993 years ago

You could make your own powdered sugar. Either in a small electric coffee grinder, a food processor or a blender. Whatever you think has a sharp enough/ fast enough blade to pulverize regular sugar. There were no Ible's on the process so eHow provided the next best thing, here. Simply omit the corn starch and you have pure powdered sugar. If you're not going to use it quickly you will want to add the corn starch to prevent clumping. While this will not create perfect one tenth size powdered sugar, it will create a much smaller crystal possibly allowing them to dissolve better. 

Thefireball3 years ago
Why does yours look red and mine loioks yellow? Is it ok to be yellow?
Will someone please tell me how much rock candy this will make. And thank you in advance.
It depends on how long you let it grow, how much sugar is in the mix, and probably several other things. There's no telling how much you'll get.
Lettucehead3 years ago
What if you added kool-aid powder for flavor? That would be really good!
JBarker09 (author) 3 years ago
I've discovered that if you add too much vanilla (and I'm sure it works the same with other flavorings as well), the crystal growth is stunted and may not grow at all. If this happens, like bikerbob2005 said, just reheat and add more sugar. Also, if you are having trouble getting the crystals to grow on a skewer, you can try coating it in some of the mixture and then a layer of sugar. Just make sure the sugar is dried on there before you put it back in the glass so they don't fall to the bottom, because then your crystal would just grow at the bottom of the glass.
if you get the temp right with out burning the crap out of the sugar you can disolve about 10 pounds of sugar into 2 cups of water and still call it a liquid. if it cools it will stay a liquid because of a thing called latenent heat. this computer does not have a spell checker on it. go reasearch 1: carnot cycle 2: the laws of thyerdymonics 3:basic air condishoning rats i can not spell any way trust me ring the bell when it is cool and the crystals will form.:)
ikoneckox33 years ago
My rock candy has not formed for some reason. we did change the recipe to 2 cups of water and 6 cups of sugar, thinking it shouldn't make a difference... any ideas? we also added all the sugar gradually instead of adding 2 then saving one... it's been 2 days so far. do i just have to wait a bit longer?
S a a - w e e e e t!  The science area of my brain was damaged in a flood.   I love, love, love rock candy.  I think the flavoured rock candy I've had always had the flavour dipped on it with some colour added, as well.  Oh, man, thank you!  I'm gonna make like a prom dress and take off ... gotta make me some rock candy.  Thanks again, I am your humble servant.

"The whole of modern thought is steeped in science ..."
MGO_Count3 years ago
bleh I want to add it on my favorites but I have to be a pro :(. I guess I'll try those contests out. And back to the inst. That's very nice. Edible science ftw! I will try this out sometime this week.
I am just a regular and it let me put it in my favorites!
You could win a pro membership here :)
I need a toaster though!! D:
You don't need a toaster, you need a grill.
lazemaple3 years ago
powdered sugar aka icing sugar has large amounts on corn starch in it and therefore will not work.
That's pretty cool! I'm going to try this with the ginger syrup thats an awesome byproduct of lemonies ginger candy.
Good idea! I still have some of that from when I made it :D
I make it mostly for the syrup now, mom likes it in her tea.
zaqzaq3 years ago
well i started it today, hope it works
mdeblasi13 years ago
I was wondering just the other day if you might make rock candy with something like reduced Torani or DiVinci brand syrup. What do you think, it might be easier than finding orgeat or hazelnut flavoring. M
You might be able to use them as flavorings, but they contain a stabilizer to keep them in liquid form, other wise the sauce pumps would turn into giant, delicious candy!
Shadow13!3 years ago
That cane sugar called Sugar in the Raw has a slightly different flavor then everyday sugar. I wonder if the color or flavor would transfer if it was used in this recipe?
I found that by adding "seed" crystals to the skewer helps start crystal growth sooner. Just dip the skewer into the solution to get it nice and sticky, i then rolled the skewer in sugar to get it to stick to it. That way the rock candy crystals can grow right off of the sugar crystals on the skewer, plus the irregular surface of the sugar coated skewer increases the overall "growable" surface of the skewer :)
JBarker09 (author)  Friggin Smift3 years ago
Great observation! The one that I am growing right now, well... It's not actually growing. I'm thinking of reheating the stuff and trying what you said. I mentioned a little bit of this at the end for future reference, but I completely agree with you!
One thing i don't understand: if it is a pure sugar crystal that is growing, how then is the flavor passed on to the candy? Why would the flavorings not just stay in the water solution? what is binding them to the sugar crystal as it grows?
JBarker09 (author)  thatoneguydavid3 years ago
That is a great question. I have no idea. the only flavoring I have tried is using vanilla, and I have found that even different brands of vanilla will change whether or not it grows with the sugar. My very first attempt the sugar came out just plain sugar and all the flavoring was left behind. I have yet to figure out the best way to flavor it, but as soon as I find out I'll post it.
don't question a miracle. =P
As to the powdered sugar issue: I don't think that it will work because powdered sugar is 3% corn starch to keep it from clumping. As far as something that will dissolve faster, you could try super fine sugar. You can make your own by whirling in a blender or food processor. Just don't whirl it too long or it will get hot and sticky. Just short, controlled bursts. For an extra credit project for science class, my son made crystals. We used food coloring and it took the color beautifully. The instructions specifically stated not to use mono-filament because it is too smooth to give crystals a place to form and it said not to use anything like a washer or paper clip. We used a wooden skewer, but I also thought that if you were using kitchen string, why couldn't you use a piece of dried fruit for a weight?
TOCO3 years ago
This is a great instructable! I have always wondered how I could make rock candy.
The Cloak3 years ago
The creation of a super-saturated solution and a demonstration of forming a crystal lattice in a delicious treat, great ible.
powdered suger has corn starch in it do not use it ! what make it work best it to force the crystals to grow , let the glass cool on the counter with the string/stick in it when it is room temp tap the glass with a spoon ie ring the bell . that will start the crystals to growing it helps it the string is not super clean..do not ask why. if no candy then reheat to about 150 deg and add more sugar. cool and ring .
fishhook2673 years ago
Hmm.Instead of water you could proboably try liquor for flavoring.
paperclip323 years ago
I'd rather buy some rock candy,because in 3-5 days my sugar craving will be gone. Great instructable anyway,I'm making some now.
HeyJD3 years ago
The first featured instructable? I can't believe there's no comments... Well I guess I'm the first!
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