Should You Refrigerate Your Butter?

Butter is a must-have in every kitchen. You’ve got to have it on hand whether you’re cooking, baking or simply spreading it on toast or dinner rolls. But there’s a pretty big divide between butter users: Should you keep your sticks in the fridge or out on the counter?

There are plenty of good arguments for both storage methods. Some people love room-temperature butter and its perfectly spreadable consistency. Others prefer keeping butter wrapped up in the fridge, only brought to room temperature when it’s needed. But which approach is actually the right, safe one? Does it even matter at all?

Find out if you’re storing your butter properly or if you might need to rethink your habits.

Proper storage depends on the type of butter you’re working with

Officially, the USDA recommends that you refrigerate all types of butter at 40 degrees Fahrenheit or colder. But that recommendation isn’t a hard and fast rule, and it doesn’t necessarily apply to all butter varieties.

Unlike many other dairy products, butter contains a whole lot of fat. It’s made up of at least 80 percent fat (about 63 percent of which is saturated fat) and just 20 percent water. Compared to dairy products like whole milk (which contains just 3 percent fat) and heavy cream (which is 40 percent fat), that’s a whole lot of fat. 

All that fat is what helps make room-temperature butter so spreadable and smooth – and refrigerated butter solidly hard. But in some kinds of butter, the high fat content also helps fight off dangers like bacteria growth and a risk of foodborne illnesses. This means that certain types of butter don’t have to be refrigerated to stay bacteria-free, but others do.

Here’s what you need to know about storing salted, unsalted and whipped butter at different temperatures.

Salted butter

If you’ve been storing salted butter outside of the fridge and on your dining table instead, there’s great news. Your storage methods are totally safe!

According to the FDA, salted butter is able to resist most types of bacteria because of its salt content. There’s only one kind of bacteria that can survive on a stick of salted butter. And there’s scientific evidence to back this up. In a 2014 research study, scientists added different types of bacteria to regular salted butter and left that butter out at room temperature. After three weeks, there was less bacteria present. Even when the butter was contaminated, very few of the bacteria managed to survive on its salty surface.

So, even though the USDA recommends storing salted butter in the fridge, research shows you really don’t have to keep your salted butter cold. 

Unsalted butter or whipped butter

While salted sticks of butter are pretty awesome at preventing and eliminating bacteria growth, that’s definitely not the case with unsalted butter. And whipped butter doesn’t exactly fare well here either.

If you have sticks of unsalted butter or tubs of whipped butter on hand, you’ve got to keep them in your fridge. With less salt content than salted butter, these two varieties can’t fight off bacteria nearly as well. When left at room temperature for days or weeks, unsalted or whipped butter can begin breeding bacteria. And unlike their salted counterpart, unsalted and whipped butters will wind up developing far more potentially dangerous (and gross) contaminants. 

Also, don’t forget to keep raw, unpasteurized butter in the fridge. This butter is the most prone to bacterial growth, and it can turn dangerous quickly if left sitting out.

All butter can go rancid if it’s not stored properly

Even though it’s perfectly fine to keep salted butter out of the fridge and on your counter or table, it can still spoil. Any and all types of butter will go rancid eventually – and some factors can cause this to happen sooner or later.

The very same high fat content that makes butter more stable than other dairy products also makes it more prone to going rancid. When butter goes rancid, its fat spoils and it starts to stink. 

Butter (or butter’s fat content) goes rancid when it starts to oxidize. This happens when it’s exposed to oxygen. Every time you open up your butter dish and let air inside, the butter begins to change and spoil. Exposure to heat and light can speed up this process, causing butter of any kind to go rancid faster. 

In general, it takes a couple weeks for butter to spoil. However, if you’re frequently opening up your butter and increasing its exposure to rancid-causing elements, it’s not going to last long at all. To make the most out of your butter, keep it in an airtight container and away from sunlight or heat sources. If you have unsalted or whipped butter, it’s also important to limit bacteria by being cautious of how many knives (or hands!) are getting inside the container.

Additionally, according to US Dairy, every type of butter belongs in the fridge if your home’s interior temperature creeps higher than 70 degrees Fahrenheit. So, on hot days, you’re going to want to make sure your butter is kept cool. 

If you’re not going through butter fast enough or simply don’t want to mess with oxygen and light exposure, err on the side of safety and refrigerate your butter. You can also switch from keeping a full stick out at room temperature and keep just a few tablespoons’ worth at room temperature. You’ll still have a bit of butter ready and spreadable when you need it. Plus, there’s an added bonus to keeping some in the fridge: Butter can last up to a month when kept cold.

Find out if you have other bad habits in the kitchen when it comes to food storage:

• Where to Put Your Produce to Keep It Fresh
• 8 Food Mistakes That Are Prematurely Spoiling Your Groceries
• Do You Know Which Produce You Can Freeze?