Bring to a rolling boil, stirring frequently (see note).
Once sugar is dissolved, remove from heat and add a small amount of food coloring, if desired.
Allow to cool completely.
Pour into the feeder and enjoy the hummingbirds!
My hummingbird feeder holds roughly 5 cups of fluid, so using the 4:1 ratio of water to sugar, that would be 4 cups of water and 1 cup of sugar. This ratio can be scaled up or down depending on how much hummingbird food you need (see blog post for further explanation).You can boil the mixture on the stovetop or in the microwave in a microwave-safe container.