Peanut butter, whether it's an opened or unopened jar, should be stored in a cool, dark place, like the pantry. An open jar of peanut butter can also be stored in the refrigerator to extend its ...

It'll last for a year in the fridge if you don't open it, but who wants to wait that long? Still, let's say you actually did forget about your jar of peanut butter — how do you know it's gone bad?

These flourless peanut butter cookies pack intense flavor into every bite. The proportions are easy to remember: a cup of peanut butter, a cup of sugar, an egg, a teaspoon of baking soda.