Step 1: Wash and thoroughly dry the apples. It’s crucial that there is no wax or moisture on the apple surface, as this will prevent the candy from sticking. Insert a candy apple stick into the stem end of each apple, pushing it about halfway through.
Step 2: Prepare a baking sheet by lining it with parchment paper or a silicone mat. Lightly grease the surface with non-stick spray and set aside.
Step 3: In a heavy-bottomed saucepan, combine the granulated sugar, light corn syrup, and water. Stir gently over medium heat until the sugar dissolves completely. Avoid stirring vigorously once the mixture begins to boil.
Step 4: Increase the heat to medium-high and bring the mixture to a rolling boil. Insert a candy thermometer and continue to cook without stirring until the temperature reaches precisely 300-310°F (149-154°C). This is the “hard crack” stage.
Step 5: Immediately remove the saucepan from the heat. Carefully stir in the black gel food coloring until you achieve a deep, opaque black color. Work quickly as the syrup will start to cool and thicken.
Step 6: Working swiftly and carefully (the syrup is extremely hot!), tilt the saucepan slightly. Dip one apple into the black candy mixture, swirling it to evenly coat all sides. Allow any excess candy to drip back into the pan. If the candy becomes too thick, you can gently reheat it over very low heat for a minute or two.
Step 7: Place the coated apple onto your prepared baking sheet. Repeat the dipping process with the remaining apples, ensuring they don’t touch each other on the sheet.
Step 8: Allow the black poison candy apples to cool completely and harden at room temperature for at least 30 minutes to an hour. For faster setting, you can place them in the refrigerator, but be mindful of condensation causing stickiness. Once set, they are ready to serve or store.