Making rock candy is a fun way to teach children about science. Kids can learn about how crystals grow from a sugar water recipe. You can explain to them that the shapes of the candy are actually the same shapes of the sugar crystals, only magnified. Then they get to eat the sweet results of the lesson. Rock candy recipes can be tricky, though, unless you get it just right. Learn the proper way to make this colourful, delightful hard candy.
Measure the water into the saucepan. Pour in the granulated sugar until it is virtually dissolved. Drop in two or three drops of food colouring and stir until it's distributed throughout the mixture.
Cook over medium heat, stirring constantly. When the sugar is completely dissolved and the mixture appears to be pure liquid, remove from heat.
Allow the rock candy to cool completely. Pour the cooled rock candy mixture into a plastic container.
Set the plastic container in a cool, dry location where it can sit undisturbed for seven to 10 days. Check on the rock candy each day to see how it changes. As the water evaporates, colourful crystals will grow.
Break the rock candy into bite-sized pieces. If it still needs to dry a bit, set the candy on paper plates or towels. Marvel over a simple recipe that created a science project and enjoy!
Make several batches with different colours of food colouring. Place each batch in a separate plastic container. See which colour forms crystals the quickest.
Tips and warnings
- Make several batches with different colours of food colouring. Place each batch in a separate plastic container. See which colour forms crystals the quickest.