Is butter better served at room temperature, and therefore soft and spreadable? Or is butter best — like revenge — served cold?
It’s not the most consequential question of our times. Yet, people have opinions.
“I like it soft, so I generally leave mine out for a few days,” says Assistant Professor Stephanie Smith, statewide consumer food safety specialist at Washington State University’s College of Agricultural, Human and Natural Resource Sciences.
Smith notes, however, that butter fat can become rancid if it’s left out at room temperature, though it’s not really a food safety issue, more of a food quality issue.
Butter is mostly fat, so microorganisms are less able to grow in it. Salted butter, especially, reduces microbial growth, Smith said.
“There’s not a huge amount of salt in there, but the addition of salt can be helpful in preventing growth,” she said.
(In a recent story on the butter question, the Wall Street Journal quoted one cook’s opinion that unsalted butter “should be a felony.”)
The U.S. Department of Agriculture recommends leaving out only as much butter as a household will use in a day or two. Smith said it’s probably fine to stretch that to five days, depending on where the butter is stored.
Don’t set it in direct sun or near a stovetop, for example. Make sure it’s in a closed container. Summer months may call for a different approach than during cooler temperatures.
Some butter-lovers favor old-fashioned crocks that suspend butter in water, but Smith said the water could actually introduce microorganisms that wouldn’t otherwise be present.
By the way, Smith said any high-fat food, such as nuts, will suffer the same fate as butter if left out too long. “It’s just going to taste bad.”