Rock candy growing at the bottom of the jar rather than on the stick is a common occurrence. This happens when your stick is too close to the bottom of the jar. It is easier for the sugar crystals to form on the bottom of the jar rather than vertically on the stick. So, when the sugar-dipped stick is near the bottom, the crystals will start to build downward, going toward the easy base rather than climb up the stick. To prevent this from happening, make sure you keep the stick at least an inch from the bottom of the mason jar. This is essential to making perfect, DIY rock candy!