How long can non-refrigerated butter stay out before it goes bad?

Answer 1

Butter CAN go bad, it can become rancid.

Commercial butter is about 80% butterfat and 15% water; traditionally-made butter may have as little as 65% fat and 30% water. Butterfat consists of many moderate-sized, saturated hydrocarbon chain fatty acids. It is a triglyceride, an ester derived from glycerol and three fatty acid groups. Butter becomes RANCID when these chains break down into smaller components, like butyric acid and diacetyl.
- http://en.wikipedia.org/wiki/Butter
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I have left mine out and not had trouble, but if it is VERY hot where you are I would suggest refrigerating it in between use or refrigeration completely. Otherwise it should last a few weeks I think. There are also crocks that you can use to store your butter (again, when weather is cooler).
- http://www.mykitchencenter.com/Details.cfm?ProdID=1175
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There is very little to worry about leaving butter out on the counter, although we do not recommend the practice. Butter is made from pasteurized milk, so unless there is gross contamination after pasteurizing (which almost never happens) the butter gets to your house in very safe condition. Butter has very little water in it (about 20% which is not much in the world of food) and it has a fair amount of salt in it (about 5-10% in the water portion) so there is little danger of pathogen growth. Butter can support the growth of molds but it usually takes several weeks and ideal conditions to occur.
- http://missourifamilies.org/quick/foodsafetyqa/qafs649.htm

Anyway, hope I helped!

Answer 2

A lot of families and people I know have never refrigerated their butter. They simply keep it in a covered butter dish on the counter or on their dining table. It won't spoil, but it will become extremely soft.

Answer 3

Yeah, pretty much forever until it's used up. My great aunts, my grandma, and my mother all kept theirs in a covered butter dish in the cupboard. So do I. If you rarely use it though, it could become rancid, but it takes ages.

Answer 4

Butter can stay out indefinately, it won't go bad.