Picture of Grow Your Own Rock Candy
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!

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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CAScreate1 year ago

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

Max-anB CAScreate3 months ago
Takes 3 days to 3 weeks depending how well u coat ur surface with sugar and what type of surfactant how well u cooked ur sugar and so forth.
Galahir9503 years ago
How much "Pure Lemon Extract" and "Maple Extract" would this recipe need? The 2 flavors would make seperate candies.
The extracts are great for flavors. I suggest mixing ur sugar solution first then splitting it into two glasses then put 2-3 nice drops in each. U can put more for stronger flavor but for one glass I wouldn't do more than a table spoon. U can also ads ur food coloring at the end so u know which one is what flavor. Best of luck.
JBarker09 (author)  Galahir9509 months ago

The amount depends on how strong you want the flavor. If it comes in a dropper I would use about 5-10 drops, then adjust to your liking.

Saturn V5 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.
Max-anB Saturn V3 months ago
Dip ur skewer or string in water then in sugar before u put it in the cooked sugar for growing it provides a good surface to grow on. ;)
JBarker09 (author)  Saturn V5 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.
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!

chances are that it was crashing out to the top because of dust or other particles on the surface, and that breaking it caused the other molecules crashing out to look for another surface- in this case, your string, but you got less growth because the solution was less oversaturated at that point. (yes, way late comment, but someone else might be having the same question)

decant it into a new glass when it grows in the side
you can break it up and eat the crystals
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.
NoahB46 months ago

why would u need aluminum foil?

MichelleV16 months ago

I love this! I made this into a science fair project. I recorded if the different type of water affected the growth of rock candy. I won 2nd place!

joemonkey5 years ago
i always used Ammonia and Bleach. that makes the coolest colors.

You can eat these you know that right?

JBarker09 (author)  joemonkey9 months ago

Reading back through these comments 4 years later and this reply still made me laugh, and I'm in class right now lol

just kidding. don't do that :)
JBarker09 (author)  joemonkey5 years ago
Gotta admit, I laughed pretty hard at this.
Love how you put some science into this! Very interesting!
JBarker09 (author)  JohnDeere3129 months ago

Thanks! It was my first instructable so I wanted to go all out. I hope to be coming up with more soon!

Vininski2 years 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!
JBarker09 (author)  Vininski9 months ago

The hotter the mixture is, the more sugar that is allowed to dissolve. You can also try coating the wooden skewer or string with sugar prior to dipping it down into the liquid. Sorry, but metal doesn't work as well because of it's physical properties. Hope it worked out for you :)

punkyc11 year ago

when did you make this?

JBarker09 (author)  punkyc19 months ago

I remember making rock candy like this when I was a child, but this instructable was posted in 2010. Hope you enjoy it!

dallinrp1 year ago
I think mixing honey and lemon juice would be a good flavor.
JBarker09 (author)  dallinrp9 months ago

Honey and lemon juice sound like they would make a great combination!

CAScreate1 year ago


mhettick1 year ago
thanks i needed a rock candy recipe!
Momarabbit4 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)  Momarabbit4 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!
Collarina4 years ago
This only make one?
Obediah5 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 RAY4 years ago
this is a great project me and the family were doing it right now as i speak great idea
Shany1204 years ago
build524 years ago
sweet!!!!! I can't wait to make it.
Instead of skewers, I use chopsticks.
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