how long does it take popcorn to get stale?
Popcorn in most cases doesn't go off or spoil. But it doesn't last forever either. Popped kernels go stale, un-popped ones dry out, and the fat in microwaveable popcorn goes rancid. Unopened ready-to-eat popcorn lasts 2 to 3 months, and between a week or two after opening or making popcorn yourself.