When in doubt, throw it out.
I PERSONALLY am a sterility freak when it comes to canning. I still get a little weirded out about eating canned foods after a year. Even my own. Especially foods that aren't pressure canned. It may be uncalled for, but as long as I'm not depending on these foods for life, I feel like I can be a little more selective. Having said that...home canned foods are a pretty nice treat here and they don't usually last a year. Every now and then I hide a jar for later and then I forget about it...and randomly find it years later.
Post apocalyptic scenario? That weirdness goes out the window...
USDA Zone 7b/ Sunset Zone 31