Whether you have a fresh uncooked ham or a package of deli-sliced ham in your refrigerator, you'll know when it's bad. Rotten ham has an unpleasant odor, weird color and may even have an abnormal fuzz growing on it. In some cases, an unpleasant smell and mold are normal. If you're unsure if the ham is safe to eat, how old it is or if it seems borderline bad, it's generally safer to dump it than eat it.
Trust your nose when it comes to food spoilage. If your ham smells funky, it's probably spoiled. Bad meat gives off a sulfur-type odor, which is almost always noticeable right away. Open up the package and take a big whiff of the ham before you prepare it or eat it. Your ham should smell fresh, salty if it's cured or possibly smoky if it's been smoked. It shouldn't be appalling to your nose.
It's normal for ham to be pink, even if it's fully cooked. This rosy color stems from the curing process that involves injecting the meat with sodium nitrate -- done to preserve freshness and improve moisture content. You'll notice that fully cooked ham is the same sort of pink as an uncooked ham. If you opt for uncured ham instead, it'll be a paler pink, almost beige color. When it starts changing to a different color, it's a sign that the ham could be starting to turn. Gray, brown, black or green tones aren't typical. If you see these colors, it's likely time to toss the ham.
Generally mold is something you never want to see on a ham. Mold can create mycotoxins, which are poisonous compounds that can make you sick. Plus sometimes bacteria grow alongside the mold, further increasing your risk of illness if you eat it. It's also possible to be allergic to mold growing on ham, resulting in respiratory issues. This is why it's critical to never sniff ham that is covered in mold. If your package of ham has a fuzzy outer coating, place it in a garbage bag, seal it and throw it away outside. You don't want those mold spores to go airborne and make someone else sick.
Bear in mind that certain types of hams may have a foul stench, like country hams. The high salt and low moisture content does not stop mold growth during the dry curing process, allowing mold to grow on the surface. This doesn't mean the ham is bad. Most molds on country ham and even salami are typically harmless if you're generally healthy. Rinse the ham under hot water and scrub off the mold with a stiff brush, the U.S. Department of Agriculture Food Safety and Inspection Service suggests.