The following signs of spoiled crab meat typically occur around the same timeframe, regardless of the type of meat you purchased and cooked. If you notice that your crab has a sour or bitter smell, you should toss the bad crab immediately. There's a fine line for some people between that fishy smell that crabs may have, and an overly fishy smell from spoiled crab meat. Go with your gut on this one, as a rotting smell is never a good sign. You don't want to risk consuming harmful bacteria from crab that has been in the fridge too long. Additionally, cooked crab meat with a sticky film or a white, milky substance covering it is rotten. It may even have a yellowish tint with an ammonia odor. Any color besides white or a red hue where the meat touches the shell is a sign of decomposition. Remember that crab only lasts a few hours when kept at room temperature. So, if you're sure you're not going to eat it, get it chilled immediately. It’s important to know exactly how long cooked crabs last in the fridge.