People use butter all the time—even on a daily basis. But sometimes we're guilty of keeping butter in our fridge and forgetting about it. If we are talking about a couple of weeks, sure, it's probably fine. But does butter expire?

Yes, butter expires.

The dates on the packages are a good place to start. For the shelf life of butter, follow that "sell by" or "best by" date you see on the cover. It's usually okay to still eat the butter a week beyond that date, but if you're thinking of eating it a month beyond that date, you'd have to store it correctly.

How to store butter

butter, box, carton
Caroline Ingalls

Butter needs to be stored properly at, or below, 40 degrees Fahrenheit. If you keep it at room temperature for too long, the oils in the butter will go rancid.

For long-term storage, put your butter in the freezer, and it'll last for 6 to 9 months. In the fridge, it should last a month past the printed date unopened and two weeks beyond the printed date after it's been opened.

Keep the butter fresh by storing, sealed, it in your fridge immediately after purchase and after each use. Use an inner shelf rather than the shelves on the door because the temperature fluctuates whenever the fridge is opened. 

How to tell if butter is spoiled

You're in luck—thankfully, it's easy to tell if butter has gone bad. Spoiled butter will be too soft or too hard and possibly even grow mold. If you're unsure, look for discolorations or sour smell and/or taste. (Don't worry: eating a small amount shouldn't hurt your health.)

Butter does expire, but it'll be okay.

You now know that butter does expire, but its shelf life is still quite long. You'll likely finish the pack before it starts to go bad, so just remember to store it correctly.