Awhile back I posted here (I think) about having cured and smoked bacon for over four years and I was compelled to discard 2/3rds of a cured and smoked belly due to odors that were "off". Well, a vendor nearby (in south Georgia) explained to me that that belly may have come from an uncut hog, a boar that wasn't castrated, And therefore the extra hormones circulating in its system will produce an "off" odor. The flavor, once cooked, was okay but you wouldn't have wanted to smell the final product even though it had been properly cured and smoked and froze in the freezer for storage.