Your senses are usually the most reliable instruments to tell if your its gone bad. Some common traits of cheese going bad are a darker color and harder texture accompanied by a stronger smell. Your cheese has gone bad when you see or smell mold growth. Once mold is visible, you should throw away any of the softer cheeses. Likewise, if there is mold on some of your shredded cheese, the entire container should be thrown out. For firmer cheeses, if you cut away the mold and an inch of the cheese surrounding the mold it is still fine to cook with.