Awful flavour is only the smallest problem with spoiled chicken. Salmonella, E. coli and several other bacteria can develop on chicken as it goes bad. To avoid illness and food poisoning, it's important to learn the various signs that chicken has spoiled. Expiration dates are helpful, but rapid and unpredictable bacteria growth combined with the temperature sensitivity of raw chicken makes it necessary to learn several signs that chicken has spoiled.
While colour and appearance are the most obvious indications of spoiled chicken, these signals don't appear until the most extreme levels of bacteria growth. Meat changing colour also isn't always a reliable sign that it has gone bad. The United States Department of Agriculture says chicken can naturally become lighter or darker while the meat is still fresh and safe to eat. Even some colours your instincts would expect as signals of bad chicken often occur in completely healthy meat. Chicken skin can appear yellow or bluish-white while it is still fresh. These unusual colours are a product of the animal's age, exercise, breed and diet. Throw chicken away if it has obvious colour changes caused by mould but look for other signals before discarding chicken that has just become slightly darker or lighter.
One of the most reliable ways to determine if chicken has spoiled is the smell of the meat. Poultry expiration dates aren't always reliable, so it's a good idea to smell chicken right when you bring it home from the store. Spoiled chicken usually has a strong unpleasant smell. If the chicken has an odour similar to yeast, ammonia or the sulphur smell of rotten eggs, the meat has gone bad.
Another easy way to tell if poultry has spoiled is to check how it feels. After chicken has become bad, it usually becomes sticky to the touch. As the meat gets older, the texture progresses from sticky to slimy. Spoiled chicken starts to smell before it gets slimy, so if the meat feels unusual, there should be additional signs that it's become bad.
While the expiration date on the package seems like an obvious way to tell if the chicken is good or bad, it shouldn't be trusted if there are signs that the chicken has spoiled. If the poultry is not cold enough while it is stored, it can easily spoil before the package indicates. To maintain a constant cold temperature, raw chicken should be stored in the back of the refrigerator, away from the door. While it usually takes longer for harmful bacteria to grow, the USDA recommends using or freezing chicken within two days of purchase.