We were eating C-rations over twenty years old in the late 60’s. They must have know more about canned processes if the new stuff is only good for a few years?
I never met a C-Ration, MRE or whatever you wanted to call them that I didn’t like - but then, I was 99 pounds soaking wet and the Army had me burning about 9,000 calories a DAY back then. ;)
And I STILL miss Army Life every day! :)