Food Science Recipe: Rock Candy

We can make food with science! Here’s a great example of that. Rock candy takes the science of crystallisation to the next tasty level. It’s a fun treat to make but it does take a lot of time and patience.

Here’s what you need:

How to do it:

  • Prepare the stick and jar setup. Suspend your bamboo skewer in the middle of the jar using two clothespins. The skewer should not touch the bottom of the jar or the sides because the crystals will form there if they do. Alternatively you could use a piece of kite string instead of a bamboo skewer.
  • Next, boil 1 cup of water in a pan. Once it starts to boil put in your food colouring and food flavours (ie vanilla, lemon essence). Slowly pour in the sugar, do it a quarter cup at a time. Mixing and waiting for all the sugar to dissolve completely before you add more. This becomes your super saturated sugar solution.
  • Let it sit for 5 to 10 minutes to cool down. Once it is a bit cooler, pour it in your jar.
  • Dip your bamboo skewer into the sugar solution and then into sugar so it the sugar clings to the skewer. This will give your crystals something to hold on to when they start to form. Prepare your bamboo skewer setup as above.
  • Your crystals will start forming in just a few minutes. Make sure you keep your jar in a dry place where it can sit untouched. You can cover the top with cling wrap or foil to avoid getting any dirt in it.
  • Note down your observations for the next 30 minutes, after a few hours and after a few days. The longer you wait, the bigger your rock candy gets.

Here’s our video on how we made it:


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