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Can Old Sugar Water Make Hummingbirds Sick?

Can Old Sugar Water Make Hummingbirds Sick?

Changing sugar water every day in the hummingbird feeder can be challenging for some of you. So, an obvious question can strike your mind, ‘can old water make hummingbirds sick?’. Or, more precisely, is it necessary to replace the food with freshly prepared sugar water for hummingbirds? Let’s find out the answers in this post! 

How much time sugar water can stay fresh? 

Sugar water gets damaged very easily. No matter how hard you try to keep it safe, the solution will become non-consumable in some time. So, if you are new to feeding hummingbirds, it’s better to know how long their nectar remains fresh. Here’s what you need! 

Sugar water gets damaged in 1-2 days if left at normal temperature. If it’s too hot outside (above 95°F), the sugar water in the hummingbird feeder will get destroyed in half a day. Also, the sugar water will become undrinkable if it contains pollen grains and dust from the hummers after some time of supplying it in the feeder. So, a replacement will become necessary in such cases.

Do you know? You cannot keep the sugar water fit even after storing it in the fridge for a very long time. It will become non-consumable within 4-5 days of storing. So, it’s not an excellent idea to stock hummingbird nectar. It’s better to prepare fresh sugar water every time you replenish their feeders. 

Can you give old sugar water to hummingbirds?

Many hummer lovers don’t know that old sugar water can make hummingbirds sick. Hummingbirds have a different metabolism than us. They react to damaged food more severely than human beings. So, you cannot take a chance giving old sugar water to the hummers. But, how old are we talking about here? Let’s understand in more detail. 

Sugar water gets damaged after some time. It is a suitable medium for pathogens like fungus to grow. Hummers can fall sick and even die if they consume such sugar water. So, old sugar water can be poison for hummingbirds. It can be tiresome but changing the old sugar water in the hummingbird feeders after a day will save their lives. Also, fresh sugar water will help you attract more birds to your feeders. 

You should not give old sugar water to hummingbirds if it was refrigerated for over 6 days. Also, you should not let the sugar water stay in the hummingbird feeders during summers for even a day. The sugar water can get rotten or infested in summers, pushing the birds to death.

During winters, don’t let the sugar water stand in your feeders for over two days. If the birds have leftovers in the feeders, it’s better to clean them well before supplying fresh nectar into the feeders. 

So, it’s better to avoid giving old sugar water to the hummers, especially when you are unsure of the nectar’s age. 

What happens when you give old sugar water to hummingbirds?

You already know that old sugar water is unfit for the hummingbirds. They can make healthy birds sick, leading them to a fatal end. But, why is old sugar water so hazardous for hummingbirds? Here are the reasons! 

It becomes less nutritious

Old sugar water has different constituents. If you keep sugar water for a prolonged period, it will decompose into other carbohydrates. Such a solution will not be nutritious and cannot provide enough energy to the hummers. 

Fermentation starts

Decomposed sugar water gets damaged easily. Soon after the decomposition begins, fermentation will start. Fermented food has more adverse impacts on hummingbirds than on human beings. So, you should replace sugar water before it gets fermented. 

Fungus growth

Fermenting and decomposed sugar water is a perfect medium for fungus growth. Do you know? Fungus is a deadly infestation for the hummers. They can kill the birds for some time if the spores enter their bodies. 

It gets crystallized

Sugar water gets crystallized if it’s kept standing for a prolonged period. Crystallized nectar becomes more sticky and gets attached to bird feathers, creating a mess for the little creatures.

Feeder pore blockage

Crystallized sugar becomes thick and sticky. It can block the feeder pores and becomes difficult to clean. Also, old and crystallized sugar water is unfavorable for the birds to drink.

Fermented sugar water attracts other animals

Fermented sugar water produces a strong odor. It can attract more animals and pests to your feeders. Birds want an isolated place to enjoy their meals. If the feeders remain accompanied by raccoons, insects, and birds, the hummers will become uninterested in drinking nectar from your feeder.

The conclusion is as below.

Old sugar water can make hummingbirds sick as it gets damaged easily and ferments causing fungus growth. Fungus is harmful for hummingbirds. Also old sugar water can crystallize, make nectar sticky and cause discomfort for the hummingbirds.

These reasons make old sugar water harmful to hummingbirds. Now, you might be thinking, how frequently should you replace sugar water in hummingbird feeders? 

The following section will help you! 

How frequently should you change the sugar water in hummingbird feeders?

Sugar water in your hummingbird feeder should be replaced after each day during summer, regardless of the temperatures. 

During the spring season, your sugar-water can get contaminated with pollen grains, especially if you use an open bowl to give nectar to the birds. So, it’s better to change the sugar water by the evening and wash the feeder properly. 

You can keep the sugar water in the feeder for around two days during winters. However, you can change the nectar if the old one appears cloudy. 

Finally, if you stock sugar water in the fridge, please ensure that you discard the leftovers after four days of storing. Serving fresh nectar to the hummingbirds will keep them healthy.

Check out this article for more in-depth info on how often to change hummingbird feeder water.


Hummingbirds are habituated to drinking fresh nectar from flowers. Their immunity system and body structures are suited accordingly. They cannot take in old, rotten, and decomposed sugar water. It does not provide the hummers with the required energy content. Also, it can kill the birds as hazardous fungus and algae grow in old sugar water. 

What’s the takeaway here? You should keep changing sugar water in their feeders from time to time. Even if you refrigerate the nectar, it’s better to restock sugar water after 3-4 days. It will keep your birds healthy and your home chirpy forever.