How to Make Rock Candy

For a science experiment we recently tried our hand at making sugar crystals, also known as rock candy. This is not too challenging, and kids love it for obvious reasons, (sugar). Whether you’re teaching about crystal formation from various compounds or you just like candy, this is a fun activity.

Ingredients:

Sugar (obviously)
A measuring cup, plate and a pot
Some bamboo skewers or cotton candy/sucker sticks to grow the crystals on. You could even grow them on string, but we used sticks.
A jar of sorts to place it in, we learned that slightly narrow and taller jars would work best.
A clothes pin.
Optional: (food dye, flavorings)

Directions:

1. Prepare your sticks by wetting half of it and rolling it into the sugar until it sticks good. This will give a base for the crystals to grow on.

2. If you wish to add flavoring/color to your candy, place a drop or two into your jars and set aside.

3. Next, measure one cup of water into a pot. You will use 1 part water and 3 parts sugar, we ended up making extra later to fill 6 jars. If you use 1 cup of water and 3 cups of sugar you can fill 3-4 standard Mason jars.

4. Next, bring water to a boil, slowly begin adding sugar while stirring. Continue adding the sugar until it all dissolves. You now have a saturated solution.

5. Carefully remove your solution from the stove (only adults or older children should handle this, as it is very hot!) Pour the liquid sugar into each jar, filling them most of the way up.

6. After your jars are filled, place one stick of sugar into the center of each jar leaving about an inch between the bottom of the jar and the stick, use a clothes pin or whatever works to keep it in place.

7. Now sit it somewhere safe from little fingers, because you will have to wait about 5 days while your crystals grow. Tip: Check on your jars after a couple days and make sure the crystals are not forming too much around the bottom and sides of the jar, gently move it a little if this happens. We could not remove a couple of ours at all at the end of 5 days, I think that if we did this maybe we would have had better luck.

8. After about 5 days, you should have some sugar crystals. You will need to break the surface around your crystal (we used a spoon) to remove your rock candy. If it will not come out, try running a little hot water around the bottom (just a little).