Sour, rotten, or ammonia-like smell
Slimy or sticky texture
Gray, green, or dull discoloration
Mold growth
Package is swollen, leaking, or damaged
Meat feels unusually tacky or dry in a bad way
Off or rancid odor after cooking
Expired use-by date
Left out at room temperature for more than 2 hours
Left out for more than 1 hour if above 90°F
Frozen meat with severe freezer burn and bad odor
Unusual softness or mushiness
Visible signs of spoilage or contamination