Rock Candy Recipe - Crystallization of Sugar - The Sci Guys: Science at

Today on Sci Guys, we're making rock candy. Welcome to Sci Guys. I'm Ryan and I'm Teresa and today we're making rock candy. Let's rock out. Different kind of rock but that's okay. This episode is a viewer recommended episode. Thank you to these viewers for the suggestion. Rock candy is made from crystallized sugar. Crystallization is the process of forming a The equipment and ingredients you're going to need for this episode includes a whole lot of sugar, a pot, a tall glass, a clip or clothespin wide enough to cover the top of the glass, wood skewers or popsicle sticks, and optionally, flavoring. The safety equipment you're going to need for this experiment include goggles, thermal gloves, and an apron or lab coat to protect from spills and splashes. Also, because the sugar solution is extremely hot, adult supervision is required. The first step in our experiment is to make a sugar solution to put on the stove. Add one cup of water to your pot, then three cups of sugar. Mix them all together until they're thoroughly mixed. Next, take one of your skewers and dip it in some water and then roll it in sugar. This will create the seed crystals for our rock candy. Once it's coated, set it aside until it's dry. While you wait for your sticks to dry, place the pot that contains the solution onto the stove and turn the stove up to high. Continue to stir your solution as it warms up. Once your solution begins to boil, stir it rapidly until all the sugar has been mixed into the solution. Once all your sugar is mixed in, this is a great time to add any flavoring or coloring. Once you're done mixing in all your sugar, colors, and flavors, remove from the burner. The next step in our experiment is to take your boiling solution and pour it into the glass in which you're going to grow your crystals. Let the solution cool for 10 minutes and then place the sugar-coated stick into the middle of the glass and hold it in place with the clip. Leave your solution in a warm dry place to cool. As it cools, crystals will begin to grow on the stick. The process of growing these crystals can take a couple of days up to a couple of weeks. Check your crystals daily and make sure that the crystals growing on the stick don't come in contact with any crystals growing on the sides or bottom of the glass. If you notice they're growing close together, reposition the stick so it's further away from other crystals. Once your crystals are done growing, use a knife to crack the top shell of your solution. Gently remove your crystals from the solution and hang them in a new glass using the clip to hold it in place to drip and dry. Once your crystals have finished dripping and drying, you'll have a delicious crystalline sugary snack. During the filming of this episode, we tried using Kool-Aid for flavoring and coloring. We had limited success and the crystals grew quite small. We think the sucralose and other additives inhibited the growth of the crystals on the sticks. When we repeated this experiment using food coloring and liquid flavoring extracts, we had greater success in growing larger crystals. To get a lighter color, we used 10 to 15 drops of food coloring and for the darker color we used around 50 to 60 drops. Let's look at this experiment a little closer. All liquids have a set solubility to a specific substance at room temperature. Some liquids have high solubilities while others have low solubilities. Solubility refers to the amount of a substance called the solute that can be dissolved into a liquid known as the solvent. In most cases, as the temperature of a liquid solvent increases, the solubility also increases. The Waterner experiment starts off at room temperature and at room temperature, the solubility of the water isn't high enough to dissolve all the sugar that we added into the pot. When we place the pot on the stovetop, the heating element raises the temperature of the water. As the temperature of the water increases, so does its solubility. And eventually, once the water is at boiling point,