The mold is growing and producing that smell. Mold spores form on ALL bread when it is exposed to air. That's why it takes a few days for the mold to actually be visible. The mold doesn't just instantly grow, it "forms" over a few days and when enough of it accumulates, you see it. read more
Yes, mold has an unpleasant odor and you probably don’t want your home to smell musty, but the potential health problems are of much greater concern than the unpleasant mold smell. Mold Odor Control. The only way to really control the mold smell is to remove the mold. read more