Ever heard the term old as dirt?
Idk how that applies to ur question but.......
Is there anyway to tell if it's gone bad?....I've had it stored in a dark cool closet^Yes sir, soil may not expire but it sure can go hella bad on ya it all depends on how/where it's been stored, When I've used FFOF or HF I always dumped it out on a tarp to aerate overnite, once it dries out enough I'll water it with some Gnatrol and let it cook a few days... unless I've amended it with something else then it cooks longer, like two weeks to two months, etc.
Yes the smell.Is there anyway to tell if it's gone bad?....I've had it stored in a dark cool closet