Does Butter Need to be Refrigerated?
How to Safely Store Butter on the Counter
For the optimal storage of butter, it should be refrigerated. For short term storage of butter, it can be kept out on the counter for a week, or two weeks at maximum. Beyond that time it may begin to spoil and develop a rancid taste.
The butter on the left has been on the counter for more than 24 hours. It is spreadably soft and slightly lighter in color than the butter on the right, which is directly out of the refrigerator. Following are additional tips about leaving butter out on the counter.
Pasteurization removes bacteria.
Dirty hands and dirty knives, just as in any food, can leave bacteria behind in this soft substance.
Don’t leave the whole box of butter on the counter, just what you will use in a week.
If your kitchen is kept above 70°F, it will not last as long.
Since butter is fat, it will begin to taste rancid at some point beyond a week.