(Chemistry for ages 5+)
There are lots of ways science can be fun, but perhaps some of the best kinds of experiments are the ones that create delicious snacks. In the video above, a couple of kitchen scientists show us how to make edible rock candy with just a few simple ingredients. Here’s what you need:
Wooden skewers or popsicle sticks
Whisk or stirring spoon
Clothes pin or clip long enough to lay across the top of the glass without falling in
Candy flavoring (optional)
Food coloring (optional)
- First, add 1 cup of water to your sauce pan, and then add 3 cups of sugar. Mix the sugar and water together, and then set aside.
- Next, prepare your wooden skewers or popsicle sticks with “seed crystals.” This is done by first dipping them in water and then rolling them in sugar to coat them. Once you have your sticks coated in sugar, set them aside to dry.
- Set your sauce pan with the sugar and water mixture on the stove and set the temperature to a high setting. Continuously stir the mixture as it warms up. Once it begins boiling, stir the mixture rapidly until all of the sugar has dissolved and the solution appears clear.
- If you would like to add any food coloring or candy flavoring, do so now.
- Remove the sauce pan from the heat and carefully pour the hot liquid into the tall glass. Let the solution cool for 10 minutes.
- After the 10 minutes are up, place a sugar-coated wooden skewer in the middle of the glass and hold it in place with the clip. Set the glass in a warm and dry place where it can be undisturbed for several days while the crystals form.
- Check on your growing crystals at least once a day to be sure the crystals growing on the stick do not come into contact with any growing on the sides or bottom of the glass. If you notice these crystals growing close together, reposition the stick so that it is farther away from other crystals.
- Once your crystals are finished growing, use the butter knife to gently crack the top layer of the solution, and carefully remove your crystals from the solution.
- Place your crystals into a new glass and hold them in place with the clip. Let your crystals dry like this until they are no longer dripping. Now you are ready to enjoy your crystallized snack!
- Adult supervision (Adult supervision at all times please)
This sugary rock candy is made through a process called crystallization. If you look closely at small grains of sugar, you might notice they have similar block-like structures. These are actually tiny crystals themselves. When sugar is dissolved into water using heat, these structures break down and melt into the water.
Then, slowly over time as the sugar water cools, the crystalline structures reform and build upon each other. That’s what makes the funky and jagged edges of your rock candy. The sugar is what makes it so sweet and delicious though.