Add half a cup of sugar and water to a saucepan. Stir over medium heat until the sugar has dissolved.
Add the grapes to the pan and stir to coat them with the sugar mixture.
Line a baking sheet with parchment paper and set a wire rack over it to catch any drips. Transfer the grapes to the wire rack and allow to dry at room temperature for about an hour.
Add the remaining sugar to a bowl, then roll the grapes in the sugar to coat them.
Place the candied grapes on a board lined with parchment paper and chill in the fridge for 30 minutes. Enjoy!
Notes
When arranging the grapes on the wire rack, ensure they don't touch to prevent them from sticking together.