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!

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
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dallinrp1 month ago
I think mixing honey and lemon juice would be a good flavor.
CAScreate6 months ago


CAScreate6 months ago

how long does it take to make these. me and my sister are making them today and we would like to know

punkyc18 months ago

when did you make this?

mhettick11 months ago
thanks i needed a rock candy recipe!
Vininski1 year 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 V4 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 V4 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
Galahir9502 years 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!
Momarabbit3 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)  Momarabbit3 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?
Obediah4 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
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.
Sagi4 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_taner4 years ago
try arenga palm (liquid) sugar ..... hmmm...
mattbomb4 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 Proton4 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 Proton4 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
HollyHarken4 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)  HollyHarken4 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) 4 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.
joemonkey4 years ago
i always used Ammonia and Bleach. that makes the coolest colors.
just kidding. don't do that :)
JBarker09 (author)  joemonkey4 years ago
Gotta admit, I laughed pretty hard at this.
Schober4 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.
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