Meat is considered spoiled when it is no longer safe for human consumption, according to Purdue University. Meat, such as steak, goes bad when it is exposed to air, is improperly refrigerated or frozen or is infested with microorganisms, such as E. coli or salmonella. There are several tell-tale signs that will let you know whether your juicy steak is edible or should be tossed in the trash.
Examine the coloring of the steak. A steak that has spoiled will take on blackened or green appearance, which is caused by the formation of mold.
Smell the steak. Meat that has spoiled will take on a distinct, rancid odor. If there is any question about the odor of the steak, throw it out to protect yourself from possible food poisoning.
Touch the surface of the steak. A steak that has spoiled will have a slimy texture. This slime is caused by an overgrowth of bacteria, and is a sign the meat has gone bad.
Read the "sell-by" date. Meat that is fresh and frozen will have a date that it is intended to be sold by. If the meat is two to three days beyond the sell-by date, do not consume it.