Wash and dry your fruit. Slice if needed. The fruit must be dry for the sugar coating to adhere properly.
Skewer the fruit, only add as many pieces as you can dip into the pot.
Add the sugar and water to your pot. Heat over medium heat until the candy thermometer reaches 275 F degrees. Do not stir the mixture. The hard crack stage is reached, 300° F so begin testing at 275 F to account for variance in your thermometer. (see notes). This will take about 10 minutes. Overheating the syrup will burn the candy.
When the sugar and water mixture has reached the desired temperature, turn the temperature down slightly to prevent burning. Dip your fruit skewer into the sugar mixture, and gently turn the skewer to coat the fruit.
Work quickly and allow excess sugar to drip off before setting on your prepared wax paper or silpat. The sugar coating should harden almost immediately.
To check the hard candy stage without a thermoeter, dip a wooden skewer in the sugar and then dip it immediately into cold water. If it hardens the sugar is ready.
When making tanghulu strawberries vendors often add a few drops of red food coloring to the sugar for a deeper color. Adding red dye is optional.
I highly recommend a silpat or wax paper for cooling the candied fruit. Alternatively, you can use parchment paper but it might stick.
Some recipes call for dipping the candy into a glass of cold water. You can do this if you find the candy is too sticky when you remove it from the sugar.