Step 1: Prepare your fruit. Wash and thoroughly dry all fruit. This is a crucial step; any moisture will cause the sugar to crystallize. For larger fruits like strawberries, you may need to hull them or cut them into bite-sized pieces. If using hawthorn berries, make sure they are cleaned. Thread the fruit onto bamboo skewers, leaving a small space between each piece and at the bottom of the skewer for handling.
Step 2: Prepare your workstation. Line a baking sheet with parchment paper or a silicone mat and lightly grease it with a neutral oil (like vegetable oil) to prevent sticking. Have it ready near your stovetop. Also, prepare an ice water bath in a small bowl for testing the sugar syrup.
Step 3: Make the sugar syrup. In a heavy-bottomed saucepan, combine the granulated sugar and water. Place the pan over medium heat. Do not stir the mixture at this stage, as stirring can cause premature crystallization. Allow the sugar to dissolve naturally as the water heats up.
Step 4: Cook the syrup to hard crack stage. Once the sugar has dissolved and the syrup begins to boil, you can gently swirl the pan to ensure even cooking, but still avoid stirring with a spoon. Insert a candy thermometer into the syrup, ensuring it doesn't touch the bottom of the pan. Continue to cook until the syrup reaches a temperature between 300°F and 310°F (149°C-154°C). This is the 'hard crack' stage.
Step 5: Test the syrup (optional but recommended without a thermometer). If you don't have a candy thermometer, drop a tiny amount of hot syrup into your ice water bath. It should harden immediately into a brittle, glass-like strand that snaps cleanly. If it's chewy, continue cooking. If it's cloudy or grainy, your syrup may have crystallized, and you might need to start over.
Step 6: Dip the fruit skewers. As soon as the syrup reaches the hard crack stage, remove the pan from the heat immediately. Working quickly, take one fruit skewer and carefully dip it into the hot sugar syrup, rotating it to ensure an even, thin coating over all the fruit. Lift the skewer out, allowing any excess syrup to drip back into the pan. Do not linger, as the syrup cools rapidly.
Step 7: Cool and harden. Place the coated Tanghulu (Candied Fruit Skewers) onto the prepared parchment-lined baking sheet. Repeat with the remaining fruit skewers. If the syrup starts to thicken too much during dipping, you can return it to very low heat for a few seconds to loosen it, but be careful not to overheat or burn it.
Step 8: Serve immediately. Let the Tanghulu (Candied Fruit Skewers) cool completely at room temperature for about 15-20 minutes, or until the candy shell is completely hardened and brittle. They are best enjoyed fresh, as the candy coating can start to melt or become sticky in humid conditions. Store any leftovers in an airtight container at room temperature for a very short period (1-2 hours); avoid refrigeration.