From the “This Just In” Dept
I was in the mood for salt, so I went to the vending machine to buy a bag of corn chips (a childhood favourite of mine) for 75-cents. I opened the bag, smelled an acrid odour and took a bite of what turned out to be a stale, rancid corn chip.
Blah.
Chip manufacturers fill potato chip bags with nitrogen gas. It must have leaked out. Nitrogen gas is relatively inert; it doesn’t react. When oxygen is introduced, it causea an oxidation reaction in the oils used to fry the corn chips. This makes them stale. In extreme cases the oil goes rancid.