 So before you understand the do's and don'ts of hummingbird food, you're going to need a recipe, and that's really, really simple. It's one cup of sugar and four cups of water. Now you mix the two ingredients together, bring it to a boil, and let it cool, and that is it. Now a bird's digestive system is very different from humans, so there are some tips to keep in mind when you're making this homemade hummingbird food. You need to pay attention to the shelf life. Homemade hummingbird food in the refrigerator, you can keep it for up to two weeks.