In a small saucepan, combine the granulated white sugar and water.
Place the pan over medium heat and stir until the sugar is completely dissolved.
Bring the mixture to a gentle boil and let it boil for 1–2 minutes to help sanitize the nectar.
Remove the pan from the heat and allow the nectar to cool completely to room temperature.
Pour the cooled nectar into clean hummingbird feeders, discarding any old nectar first.
Store any leftover nectar in a covered container in the refrigerator for up to 1 week, and refill feeders as needed.