Ingredient Intelligence

Does Butter Go Bad? Yes — Here’s How to Tell.

published Jun 14, 2022
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butter in the bell jar with lid near it
Credit: Photo: Joe Lingeman; Food Styling: Brett Regot

Butter may be a kitchen staple, but how much you use and how often varies from cook to cook. While some may churn — pun intended — through pounds of butter baking cookies and cakes, others may only occasionally spread a bit of butter on toast.

In either case, it’s important keep track of how long you’ve had butter and store it properly. Butter lasts a surprisingly long time — even at room temperature — but like most foods, it does eventually go bad. Read on for everything you need to know about butter’s shelf life, including how to store it and for how long. 

Why Does Butter Go Bad?

Although butter is made from milk, it has the potential to last much longer. This is because it has a much lower water content, which makes it harder for bacteria to grow. Salted butter has an even lower risk of bacterial growth because salt lowers the water content even further. 

Butter also has a high fat content and that fat acts like a protective barrier, further preventing bacteria from forming. On the flip side, all that fat makes butter susceptible to spoilage. As it is exposed to light, heat, and oxygen, butter oxidizes, which alters its molecular structure, changing the taste, texture, and even color. 

How to Tell If Butter Is Bad

Although you should look for mold, you’re more likely to see subtle signs of spoilage like changes in color or texture and off smells. And although spoiled butter probably won’t make you sick, it certainly won’t taste good. If your butter smells or tastes sour or rancid, it’s time to toss it.

What’s the Best Way to Store Butter?

Anyone who’s tried to spread fresh-from-the-fridge butter on toast knows how hard those sticks can get (here’s seven ways to soften it, which is why some cooks prefer to keep butter on the countertop. Unlike milk, yogurt, and many other dairy products, butter’s low-water, high-fat content means it can safely be stored at room temperature for a limited time, especially if it’s salted butter. Unsalted butter won’t keep as well at room temperature, and whipped butter should always go in the fridge. 

Storing butter at room temperature: Butter kept at room temperature should be stored in a covered container, such as a butter dish or a French butter keeper, to protect it from heat, light, and oxygen, all of which encourages spoilage. Also consider how much butter you use and how quickly. If you’re only using a pat here and there, keep just a few tablespoons at room temp and refrigerate the rest, so nothing goes to waste. 

Storing butter in the refrigerator: For slightly longer-term storage, keep butter in the refrigerator, preferably in the coldest part, which tends to be the back, and avoid keeping it in the door, where the temperature fluctuates.

Storing butter in the freezer: Infrequent butter users or those who buy it in bulk should store butter in the freezer. 

Whether storing butter in the fridge or freezer, it can help to keep it in its original packaging, which is designed to protect butter from light and air, as well as odors (butter is delicate and easily picks up smells from nearby foods). 

For freezer storage, pop wrapped butter in a freezer bag or add a layer of plastic wrap or aluminum foil for added protection against odors and freezer burn. When freezing butter, or any food, be sure to label and date it, so you can easily identify it and use it before it’s too late. 

There are also lots of different butter containers if you discarded the original packaging or prefer not to store it that way. 

How Long Does Butter Last?

How long does butter last at room temperature? If properly stored, butter can keep at room temperature for a few days or even a week.

How long does butter last in the refrigerator? Of course, if it’s the height of summer or your kitchen is particularly warm, that butter is best moved to the refrigerator. In the fridge, it will last about a month past the package date if unopened and about two weeks past the package date once opened.

How long does butter last in the freezer? Butter can also be well-wrapped and frozen for six to nine months.

Butter’s shelf life depends on proper storage and it’s important to note that while butter may be safe to eat, quality always diminishes over time. Even if well-stored, butter that’s been frozen for four months simply won’t taste as fresh and delicious as butter you just purchased. If your butter supply is nearing the end of its shelf life, turn it into biscuits, blondies, a buttery pasta, or this quick lemon-butter sauce that’s delicious drizzled over veggies, cooked protein, or grains.