Hummingbird Nectar Recipe | Smithsonian Migratory Bird Center
https://nationalzoo.si.edu/migratory-birds/hummingbird-nectar-recipe
Directions for making safe hummingbird food:
Mix 1 part sugar with 4 parts water and bring to a boil to kill any bacteria or mold present.
Cool and fill feeder.
Extra sugar water may be stored in a refrigerator.
Red dye should not be added.