Butter is a staple in many households, and for good reason – after all, who doesn’t like a pat of butter on freshly baked bread or topping a baked potato? (If you’re a vegan or are allergic to dairy, then look no further than coconut oil, a great butter substitute!)
Butter typically won’t go bad very quickly – it lasts several weeks in the fridge even after being opened and can be out at room temperature for at least a few days. Sealed butter lasts even longer at 4-6 months in the fridge or freezer. Beyond those dates, butter isn’t likely to be obviously rancid, but it might lose its ideal texture and taste if you decide to use it past then.
You likely have butter in your kitchen right now, but how do you know if it’s gone bad? And what are the best ways to store it? We’ll answer those questions and more next!
What is the shelf life of butter?
Regular butter (not counting plant-based buttery spreads or anything) contains cow’s milk, which doesn’t stay good forever. The main reason butter can go bad is when the fats go rancid, which is when the chains of fat molecules break down over time due to factors like heat, light, and oxygen.
When stored in the refrigerator, butter should last at least three months, if not longer. Three months is ideal to maintain the flavor and quality of the butter. If you don’t plan to use butter within those three months, then the freezer is the best place for it (we’ll talk about that more soon!) to maintain its freshness.
How long does butter last after opening?
If you haven’t opened your container or stick of butter yet, there will probably be a “use by”, “sell by”, or “best by” date printed somewhere on the package. It’s safe to assume you can store the butter in the fridge at least until that date if it’s unopened (after all, butter is stored in the refrigerator at the grocery store!).
However, once it’s opened, you should aim to use butter within 2-3 weeks to preserve its freshness and quality. Will anything bad happen if you store opened butter longer than a few weeks? Probably not, but it likely won’t taste as good as if you used it when it was fresher.
Salted butter will likely last a few more weeks than unsalted butter (so more like a month) since salt acts as a preservative, so take that under consideration!
Can you use butter after its expiration date?
It’s important to note that butter might not have an expiration date, but instead a “sell by” date. That was the case for us when we checked the butter in our fridge – sure enough, there was simply a “sell-by” date without any expiration date listed on the package.
(Interesting observation – the sell-by date on our butter was for six months past when it was purchased, hinting that sealed butter can last at least six months in the fridge! Hmm…)
If your butter has an expiration date and it’s been stored in the fridge, it’s likely safe to use it for up to a month after the expiration date. The main concern with using expired butter is that it won’t taste as fresh as it could, but it’s not likely to cause any safety issues if it was stored properly and sealed.
How to tell if butter has gone bad
Butter has a longer shelf life than most dairy products (milk, yogurt, cheese, etc.), but it can go bad.
It’s not very likely that butter will get moldy because it has lower water content and higher fat content than other dairy products (bacteria need moisture to grow), but technically it’s possible. For reference, butter is around 18% water compared to yogurt’s nearly 90%, which is why you’re more likely to spot mold in old yogurt than you are in old butter.
The more likely outcome is that butter will have an “off” taste if it goes rancid, which is when the fatty acids are broken down by things like heat and oxygen. You can also tell if your butter has gone bad if it gives off a sour odor.
Speaking of odor – butter can absorb the odors of nearby foods, potentially altering its taste. So unless you want your butter to taste like the fish it was stored next to in the fridge, seal it tightly to preserve its flavor and quality!
What’s the danger in using butter after it’s gone bad?
The main danger in using butter past its prime is that its taste and texture won’t be ideal, which can negatively impact your baked goods or whatever else you’re using it for.
While you might get a sour stomach from eating rancid butter (the smell and taste would likely stop you from eating too much!), butter isn’t a common source of foodborne bacteria like raw meat and other highly perishable foods.
Best storage practices for butter
- Once opened, keep butter wrapped tightly in plastic wrap or keep it in an airtight container to preserve freshness. This also keeps the butter from absorbing odors from other foods nearby!
- Choose opaque containers to block light from reaching the butter. Also, glass or porcelain containers are best – using plastic containers that have absorbed odors from other foods could seep into the butter.
- Keep butter away from direct sunlight (such as next to a window), which can cause it to go rancid much faster than if stored away from light. You should also keep it away from direct heat, such as the oven.
- If you’ve stored butter in the freezer and it develops ice crystals, it’s best to toss it. The texture and taste are likely altered by that point due to freezer burn.
While there isn’t an exact science on the shelf life of butter, here are some general guidelines to help you decide how long to store it!
|Room temp (counter)||Fridge||Freezer|
|Opened butter||1-2 days (likely more like 3-4 for salted butter)||2-3 weeks (likely at least a month for salted butter)||<=4 months (err on the side of caution and use sooner if it’s been opened for a bit)|
|Sealed butter||At least 1-2 days (likely a few more for salted butter)||At least 3 months (possibly up to 6!)||At least 4-6 months (possibly longer for salted butter)|
A butter crock is an ideal container to help keep butter fresh at room temperature. A butter crock uses water to create a tight seal, keeping air and odors away from butter while keeping it spreadable at room temperature.
Butter isn’t likely to go bad quickly, lasting several weeks once opened in the fridge. Sealed butter is even less likely to go bad, keeping around 4-6 months (likely even longer) when stored in the fridge or freezer.
Yes! The salt acts as a natural preservative, so, for instance, opened salted butter at room temperature will stay good for 3-4 days vs. 1-2 days for unsalted butter.