Can old cereal make you sick?
“Cereals don’t really go bad. There is not that much of a quality issue. If you leave your cereal box open, it can get stale, but you are still not going to get sick from it,” Emily Broad Leib, the director of Harvard Food Law & Policy Clinic, told TIME magazine.
Secondly, Does cereal expire if not opened? Cereal. Shelf life: When properly stored, unopened cereal will last 6-8 months past a “best by” or “use by” date.