Ground beef that has gone bad has an unpleasant odor and a telltale grey-brown hue. When fresh, all raw red meats have a vibrant red-pink appearance and do not have a strong odor. Fresh ground beef also contains tiny flecks of white fat.
The odor of bad ground beef is cloying, sickeningly sweet and musty. When this smell is present, the beef is not safe for consumption by humans or animals and should be discarded immediately. If the meat has a grey cast but smells fresh, it is edible but must be cooked immediately.
Eating raw meat is dangerous because of the harmful bacteria it may contain. Meat that is on the verge of going bad should not be used for raw preparations, such as steak tartare. Well-done hamburgers, steaks and other dishes are better choices for this type of meat because the high cooking temperatures kill the bacteria.
To minimize the chances of purchasing meat that has already spoiled, shoppers should check its expiration date, note the color of the meat, and sniff the package for rancid odors. If the meat passes these tests, it is edible. Cooking beef on the day of purchase ensures maximum freshness and juicy flavor. According to Eat By Date, ground beef tolerates freezing for up to eight months and refrigeration for up to two days.