Chances are, you use butter at least once or twice a day around the kitchen. You might start off with toast or a muffin in the morning, then use it again to fry an egg to go over your salad at lunch. You definitely use it whenever you bake (regardless of whether you use salted or unsalted butter), and of course, butter is a given for your evening popcorn and binge-watching fix. The question is, do you get the butter out of the refrigerator every time you use it, or can you leave butter out on the kitchen counter in a covered dish? If you leave it out, how long can butter sit out?
Cold butter right out of the refrigerator is impossible to spread. Keeping butter at room temperature means that it's spreadable anytime you want it, but most of us still refrigerate butter because that's what we think we're supposed to do. For those who are looking for the most spreadable, usable butter, here's how long butter can sit out before it's time to be thrown away.
Can butter be left out on the counter?
We tend to think that because butter is a dairy product, made from cream, there's a food safety issue with leaving the butter out on the counter. But is that true? Let's walk through what makes butter different and why storing butter at room temperature is okay, within reason.
Yes, butter is a dairy product. But the type of butter you buy at the grocery store is a pasteurized dairy product with high-fat content and a low level of water molecules, about an 80/20 percent ratio. Pasteurization, plus the fat and water content, means that it's harder for bacteria to grow. Salted butter has an extra layer of protection against bacterial growth due to the salt.
So it's safe, but for how long?
According to the USDA, butter is safe at room temperature. But if it's left out for several days at room temperature, it can turn rancid causing off flavors. The USDA does not recommend leaving it out more than one to two days. This partly depends on the type of butter you're using. Salted butter will last longer than unsalted butter, so if you're planning on leaving it out for a few hours, use the butter with the highest content of salt you can. This butter will do great at room temperature for a couple of days, but after that, it should be used up or put into the fridge.
If you're leaving your butter out to use in a recipe later in the day, so that you'll have room temperature butter that's easily creamed or mixed into your recipe, you can always play it safe by simply keeping it in the fridge and then microwaving it for a few seconds when it's time to use it. If you're using unsalted butter or whipped butter rather than salted butter, it's safest to keep these in the fridge no matter how soon you're planning on using them. This is especially true if your kitchen will reach higher than 70 degrees F. If your kitchen is this temperature or warmer, you should keep salted butter in the fridge as well. If you have too much to use up, you can always freeze butter for up to a few months.
For more insight, the USDA says this about room temperature butter: "Butter and margarine are safe at room temperature. However, if butter is left out at room temperature for several days, the flavor can turn rancid so it's best to leave out whatever you can use within a day or two. Margarine, especially soft tub margarine, can separate into oil or water and solids when not kept refrigerated although it will be safe." So, for the question of how long butter can sit out, it depends the type of butter and the temperature of your kitchen.
You'll know if your butter on the counter turns rancid; it will smell off and it will taste terrible. (Trust me, if you've ever tasted oil or butter that's turned, you'll never forget the taste.) It generally doesn't happen overnight but leave the butter out long enough and it will go bad.
Tips for leaving butter on the counter
Exposing butter to air and light is what helps along rancidity, so if you'd rather leave your stick of butter on the counter, keep it in a butter dish, butter crock, butter bell, or another airtight container. It's best to only leave out what you can use up in a day or two in your butter keeper. If you use butter every day, a butter keeper is a must! When figuring out how long butter can sit out, it does partly depend on how you store it.
And, just a reminder, if your kitchen is consistently on the warm side (over 70 degrees Fahrenheit), you might want to leave the butter in the fridge until an hour or so before you want to use it. That way you get soft butter with a longer shelf life.
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This article was originally published on May 15, 2020.