Introduction: How to Make Rock Candy

but not just any rock candy.... This is, boulder candy...

Step 1: Materials

Sugar
Water
Large Pot
Cotton String
Skewer Stick, spoon or something that covers the span of your jar
Jar

Step 2: Preparation

Fill your jar with water leaving some empty space at the top. Pour this water into a pot.

Place the pot on the stove over medium heat. Heat until you start to see steam rise off the surface of the water. Now, slowly stir in sugar. Keep adding sugar until vigorous stirring does not dissolve additional sugar.

Next, pour the sugar syrup into a jar. Take care not to allow any sugar sediment to pour into the jar.

Step 3: Make Candy!

Tie a long piece of cotton* string to a spoon, fork, skewer, etc. Then, measure the height of your jar and trim the string to this length. You may need to weigh your string down to keep it straight. For this, you can use anything that sinks in water - but avoid lead.

Place your jar in a place that it won't be disturbed for about a week.

After about a week, pull out your candy! If you don't see any growth within the first few days -- drain the sugar water into a pot, heat it and add more sugar. Also check that your string isn't super slippery.

If ants are a problem, place your jar on a plate of water - then add a few drops of detergent. This makes an ant moat.

Here at instructables HQ -- ants are a problem when it comes to leaving food on the counter.

*Do not use nylon or other synthetic stings as these are too slippery for candy crystal growth. Coarse cotton twine works best, providing locations for crystal growth to begin (these are called nucleation sites).

Step 4: Break Through

My rock candy was left in the jar for too long... So, to salvage - I had to break my jar for the full effect. Wear safety glasses ;)

Step 5: How It Works

By heating and agitating water while adding sugar, a saturated liquid is formed. As the syrup cools and evaporates, the fluid becomes super saturated - meaning the water has more sugar than it can hold. When this happens, sugar looks for a place to escape - these places are called nucleation sites and sometimes called "seeds."

The string provides the nucleation sites for crystal growth. As the water evaporates, more sugar crystallizes on the string - growing the rock candy.

Comments

author
shatteredbreeze (author)2015-07-05

made it! one with vanilla, one with brown sugar, and two each of orange and strawberry flavor. gonna see how they turn out in a week or so. i used hemp string for a rustic look. hopefully it'll turn out with some nice crystals.

author

Did you take any pics?

author
The cloud 1808 (author)2016-03-28

? =}

author
luh_bri (author)2015-11-18

THIS IS AN GREAT WAY TO GET AND A+ ON AN SCIENCE PROJECT

author
Wlngfrvr (author)2015-10-21

I love cj rey mwaa

author
Wlngfrvr (author)2015-10-21

I love cj rey mwaa

author
Wlngfrvr (author)2015-10-21

I love cj rey mwaa

author
Wlngfrvr (author)2015-10-21

I love you cj reyy mwaaaa ?

author
Wlngfrvr (author)2015-10-21

Ncba students.
I cj rey mwa mwaàa

author
funny70 (author)2015-01-07

Can u use mio for flavoring??

author
Max-anB (author)funny702015-05-23

Yes also Walmart has several flavors for under $3 a piece for 2 oz and u really only need a small amount to flavor ur candy.

author
RoseW2 (author)2015-03-10

I don't know why, but my sugar keeps coming off my stick?? I have tried many different solutions but it will not stay. Can you help me?

author
Max-anB (author)RoseW22015-05-23

If u r using string or wood I recommend dipping it in water then dip it in sugar lightly coating ur surface for growing the rock candy. It will give the candy something to grow on. :) good luck next time.

author
JenniferS2 (author)2014-11-15

Can you flavor/make it with kool-aid?

author
sector47 (author)2008-05-16

who wants candy!!!

author
esparanzak (author)sector472014-09-17

Count me in!!!

author
Shany120 (author)sector472011-03-08

I do!!

author
mason0190 (author)sector472008-08-10

I DO!!! :D

author
Huntman00 (author)2010-03-05

Can u wash out that pot easily... my mom mite get pissed if i do this... please reply soon

author
Jimmy Proton (author)Huntman002010-07-31

as long as the sugar doesn't caramelize then it will come off with water

author
SKelem (author)Jimmy Proton2013-10-03

If it does caramelize, you can fill the pot with hot water, and the caramel will dissolve.

author
csk14 (author)2010-06-02

Can you color the candy?  Maybe put food coloring in the water or ad a fruit.

author
Goygar (author)csk142011-11-14

Adding food coloring or fruit gives no real problems. But to flavor the candy, it is best to add a candy flavoring or an extract of some flavor.

author
jeanphyl (author)2011-03-16

Wow this is new.Did u actually eat it?

author
Jimmy Proton (author)2010-08-18

ive had mine out for over 2 weeks and nothing has happened

author
DrWeird117 (author)2009-08-15

Smoke it.

author
Huntman00 (author)DrWeird1172010-03-05

you can do that... then comment in a week and we will see if u lived

author
crazygurl (author)2010-01-13

i love sean!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

author
crazygurl (author)2010-01-13

is it eatable?????????????

author
crazygurl (author)2010-01-13

tis is the fucken bomb

author
mae-kitty (author)2009-11-14

 KoZuEst, the pantyhose was a great idea. I tried to and it kept everything out. =D and also, if your having trouble growing the seed and or the crystal, either go out and buy rock candy then use that as the seed, or you can do what i did. Use a sugar cube. It works great lol.

author
EncasedDeath (author)2009-10-06

if i put it in a cold area will it harden quicker and not have to wait a week?

author
link605 (author)2009-10-03

to the author you should add a washer to the bottom of the string to keep it straight so if you make more candy you will still have a jar : - )

author
namraps (author)2009-09-19

Maybe I'm missing it, but I saw nothing about the amount of sugar.

author
trebuchet03 (author)namraps2009-09-20

Step 2

Keep adding sugar until vigorous stirring does not dissolve additional sugar.

author
chi chi chippy (author)2009-09-18

can u make it on a skewer like you see if u buy rock candy from a store?

author
circlethewagons (author)2009-09-16

I followed the instructions and filled the bottle close to the top like you said, and ended up with way too much sugar water. Considering that you have to mix in twice the amount of sugar as water in order to reach the saturation point, you end up with about one and a half times as much liquid. Next time I'm only going to fill the jar a little more than half way. Another tip is to wet the string with water, then coat it with sugar, and let dry. This will attract additional crystal formation. Also, use a paper clip tied to the end of the string and keep it from touching the bottom or sides of the jar.

author
Jent13 (author)2009-09-12

To get bigger rock candy crystals after you have made the sugar syrup dip the string in it then roll it around in some sugar. Let dry. the put it in the jar. I did that and i got bigger sugar crystals because they had something to grow on and it keeps them from growing on the bottom and sides as much because it has a better texture.

author
dchall8 (author)2007-07-20

My daughter likes to buy rock candy sticks. The ones she gets have clear (no color), red, green, blue, and yellow crystals - sort of like a rainbow from top to bottom. I wonder how they do that?

author
noname420 (author)dchall82009-09-12

ok on my next batch of rock candy i have an idea, my idea is to put a little sugar water is put half in color it, color the other half while still in the pot than carfull put it ontop so see if one will stay ontop of the other, if they do they might do it with 5 colors

author
colinludwick (author)2009-06-25

cool

author
KoZuEst (author)2009-05-21

A better alternative for the string would be a wooden stick. Probably something like those bamboo BBQ skewers, although bamboo might also be a bit too "slippery". I just think using a stick instead of a string makes the candy better to eat.. like a lollipop. Chewing on a piece of string is somewhat unpleasant. Also, maybe something to protect from the dust? If it needs to sit there for a week.. there will probably be some dust or dog hair in it. I don't like hair in my candy.

author
trebuchet03 (author)KoZuEst2009-05-21

You can dust cover as long as it allows the solution to evaporate, that is, no airtight covers (probably not plastic either) ;)

author
KoZuEst (author)trebuchet032009-05-21

Pantyhose.. :D I know, they put jars of water covered with pantyhose in pianos to keep the humidity levels stabile.

author
natethegreat88 (author)2009-05-08

Ummm... I think I should make some Root Beer rock candy! *drools*

author
mynameishamm (author)2009-05-03

brazilian sugar works?

author
dinosoarzsayrawr (author)2009-04-26

its sweet literally! :D I need 2 make some! actually my friends made rock candy for science class, they wanted to make flavored rock candy and used kool aid instead of sugar. I guess because it was so sugary because of the kool aid it grew bigger faster! I wonder about ice tea rock candy?

author
seasonticket1256 (author)2009-04-11

yummy candy

author
d2j5 (author)2009-04-03

nice! finaly i know how to make rock candy. i have been looking all over for ideas

author
ChristianDBrave (author)2009-03-25

When would you add flavor? Before or after you make the syrup?

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