Disney's Frozen inspired Rock Candy -A fun idea for a "Frozen" themed party! Place 1 cup sugar, 1/2 cup light corn syrup and pinch of salt in a heavy pan. Over low heat, slowly bring mixture to a boil, stirring often. Let it boil until it reaches 300˚ or hard crack stage. Remove from heat and add 1/2 tsp peppermint extract and 4 drops neon blue food coloring. Stir. Poor in a parchment lined pan. Let cool completely. Use your hands or a knife to crack the candy into smaller pieces.