Make Homemade Rock Candy
Equal parts science & cooking, this simple experiment takes some time but has a sweet payoff. Experiment courtesy of The Spruce Eats.
Master this basic recipe, then play around with color & flavor combinations…
Materials
2 cups water
4 cups granulated sugar
Optional: 1 /2 to 1 teaspoon flavoring extract or oil
Optional: 2 drops food coloring
Glass jar
Cotton thread
Prepare Your Materials
Clean your glass jar thoroughly with hot water
Cut a length of a thick cotton thread a few inches longer than the height of the jar, and tape it to a pencil
Place the pencil across the lip of the jar, and wind it until the thread is hanging about 1 inch from the bottom of the jar. Attaching a paper clip to the bottom of the thread will weigh it down and help it hang straight.
Make Your Rock Candy
Wet thread with water and roll it in granulated sugar. This base layer gives the sugar crystals something to grab when they start forming. Set aside to dry while you prepare the sugar syrup.
Place the water in a medium-sized pan and bring it to a boil. Begin adding the sugar, one cup at a time, stirring after each addition. You will notice that it takes longer for the sugar to dissolve after each cup you add. Continue to stir and boil the syrup until all of the sugar has been added and it is completely dissolved. Remove the pan from the heat.
If you are using colors or flavorings, add them at this point. When using an extract, add 1 teaspoon of extract; for flavoring oils, only add 1/2 teaspoon. Make sure you don’t stand right in front of the pan because the scent can be very strong as it rises in the steam. Add 2 to 3 drops of food coloring and stir it in to ensure an even, smooth color.
Allow the sugar syrup to cool for approximately 10 minutes, then pour it into prepared jar. Lower one sugared string or skewer into each jar until it hangs about 1 inch from the bottom
Carefully place your jar in a cool place, away from harsh lights, where it can sit undisturbed. Cover the top loosely with plastic wrap or a paper towel
You should start to see sugar crystals forming within 2 to 4 hours. If you see no change after 24 hours, try boiling the sugar syrup again and dissolve another cup of sugar into it. Then pour it back into the jar and insert the string or skewer again
Allow the rock candy to grow until it is the size you want. Don’t let it grow too large, otherwise, it might start growing into the sides of your jar! Once it has reached the desired size, remove it and allow it to dry for a few minutes, then enjoy or wrap in plastic wrap to save for later.