How quickly does peanut butter mold or go bad?

The oil in peanut butter turns rancid, but it takes longer than a week. The bread would be the worry - it will go mouldy after a few days. And if you put butter or margarine on the sandwich that will develop a sour smell. If the sandwich is wrapped in cling film or is in a container, there shouldn't be too much smell after one week. Don't leave it much longer than that though.

It's not the peanut butter that probably will go bad first--it will be the bread. Don't eat the sandwich if it's been sitting in your locker for a week. The bread will be moldy, even if the peanut butter is still good. It probably won't stink up the locker, however. Just toss it out.

Hi,

Peanut butter can be stored at room temperatures without a problem because it doesn't have enough water in it to support bacterial growth or molds or other ugly stuff. It will become rancid after a period because of the oil and taste strange and you will want to dispose of it.Peanut butter will last 9-12 months without refrigeration.

thanks

Peanut butter commonly does not help micro organism and/or mould growth because of fact of its low moisture content (under a million%) and intense oil content. in spite of the undeniable fact that, the oils can grow to be rancid with the aid of the years. while peanut butter grow to be rancid, it develops a wierd, oily style and smell. There are quite a few aspects that make contributions to the time it takes for peanut butter to grow to be rancid (i.e temperature, ingredients, oxygen availability). unquestionably, if it nevertheless tastes and scents ok, its in all likelihood nevertheless risk-free to consume, yet maximum peanut butters start to coach rancid after 9 to a minimum of 365 days under frequent situations. additionally.....Tiny bugs and bits of bugs are often in the peanut butter.....the USFDA helps a definite volume to ensue in food.

the bread would mold before the peanut butter it will be fine just don't eat it like you said