How long does peanut butter last once opened?
Hereof, how can you tell if peanut butter has gone bad?
Sight is usually the most reliable way to tell if your peanut butter has gone bad. A common trait of bad peanut butter is a change in texture from soft and creamy to hard and dry. The color of the spread may also become darker and the pleasant aroma disappears. If the peanut butter begins to smell rancid, toss it.
Also, does opened peanut butter go bad?
Past this date, if it's unopened it's still perfectly good. Opened, peanut butter will slowly develop off-flavors of rancid nuts over the next five or so years before it'll taste so bad not even the most peanut butter-obsessed child will go near it. But it's still very unlikely to make you sick.
Low moisture levels and high oil content keep this butter from going bad for quite some time, but don't go ignoring that expiration date just yet. Peanut butter can go rancid in about a year and lose its flavor. While fungi and bacteria won't ruin your peanut butter, oxygenation eventually will.