Sour, rotten, or ammonia-like smell
Slimy or sticky texture
Gray, green, or brown discoloration
Mold growth
Package is bloated, leaking, or damaged
Beef feels unusually tacky or dry in a bad way
Strong off odor after opening
Past the use-by or expiration date
Left out at room temperature for more than 2 hours
Left out for more than 1 hour if the temperature was above 90°F
Cooked beef has an unusual smell, taste, or texture
Visible signs of spoilage anywhere on the meat or packaging