Everyone loves experimenting, but I’m sure we all wish we could get a little something more than knowledge out of it. This is why I’m providing a chemistry experiment where one could eat at the end of it- How to Make Rock Candy.
Rock Candy has been a wonder for kids across the United States, and now you can help your kid master the secret to this quartz-like substance. The Rock Candy’s primary ingredient is sucrose and water. This recipe which teaches you to make crystals and to see the sugar’s structure on a large scale, will provide you with a fun (and tasty) product in the end.
MATERIALS
-2 cups sugar (sucrose)
-1 cup water
-clean glass jar
-cotton string
-pencil or knife
-food coloring (optional)
-flavoring (optional)
-Lifesaver candy (optional)
-pan
-stove or microwave
PROCEDURE
1. Pour the sugar and water into a pan
2. Heat the mixture to a boil, stirring constantly. You want the sugar solution to hit boiling, but not get hotter or cook too long. You run the risk of burning the sugar, or if you overcook slightly, it will produce hard candy, and not rock candy.
3. Stir the solution until all the sugar has dissolved. The liquid will be clear or straw-colored, depending on which kind of sugar you use. Raw sugar looks gold. The mixture will be without any sparkly sugar.
4. If desired, you can add food coloring and flavoring to the solution. Any artificial flavoring you have in your house will suffice. You could also use juice from lemons, oranges, or limes for natural flavor, but be careful, the acid and other sugars may slow down the crystallization.
5. Set the pot of sugar syrup in the refrigerator to cool. You want the liquid to be about 50F which is slightly cooler than room temperature.
6. While the sugar solution is cooling, prepare your string. Cotton string is used because it is rough and non-toxic. Tie the string to a pencil, knife, or other object that can rest across the top of the jar. Make sure the string is able to hang into the jar, but not touch the sides or bottom.
7. You want to seed the string with crystals so that the rock candy will form on the string rather than on the sides and bottom of the jar. There are two easy ways to do this. One is to dampen the string with a little of the syrup you just made and dip the string in sugar. Another option is to soak the string in the syrup and then hang it to dry, which will cause crystals to form naturally.
8. Once your solution has cooled, pour it into the clean jar with the cotton string secured inside. Set the jar somewhere quiet. You can cover the jar with a paper towel to keep the solution clean.
9. Check on your crystals, but don’t disturb them. You can remove them to dry and eat when you are satisfied with the size of your rock candy. Typically you want to allow the crystals to grow for 3-7 days.
10. You can help your crystals grow by removing (and eating) any sugar that forms on top of the liquid. If you notice a lot of crystals forming on the sides and bottom of the container and not on your string, remove your string and set it aside. Then repeat steps 1-3. Add it to a clean jar and suspend your growing rock candy crystals once again.
This is an easy, but suspenseful treat the whole family will enjoy. It’s a great activity for children when it’s rainy outside or when you just want to bond with your children. Enjoy!
