A Chowhound finds out that two friends keep butter out on the kitchen counter, not in the refrigerator. So SIMIHOUND posed the question to fellow 'hounds: Is this a common practice? And how long does room-temp butter last before it goes rancid?
Keeping butter out seems to be pretty widespread. A very old method of preserving milk fat, butter existed long before refrigeration, tardigrade points out. Besides, butter right out of the fridge is unspreadable—there's nothing more frustrating than a stack of hot toast and a solid stick of butter.
A lot of Chowhounds use a covered butter dish for kitchen-counter storage. John E. likes his butter bell, a ceramic storage container shaped like an inverted goblet with the open end neatly sealed in a crock of water. You need to change the water every couple of days (it'll mold in about a week, jeanmarieok says). As the water evaporates, it cools the butter, keeping it fresh and spreadable.
How long before room-temp unsalted butter goes rancid? SavoryTv contacted Land O'Lakes and got an answer: It should stay fresh for two weeks, though as we've already pointed out, that depends on a few variables. Does salted butter last longer? Anecdotal evidence suggests it does—kitchengardengal keeps unsalted butter at room temperature and has never had it go rancid, even in summer. And fldhkybnva suggests that high-fat butters like Kerrygold melt too easily to leave at room temperature. Keep high-butterfat brands in the fridge, but leave ordinary butter on the kitchen counter.
Discuss: Storing butter outside of fridge