Smells sour, fermented, or like vinegar
Has mold on the skin, crown, or cut surface
Feels very soft, mushy, or leaking liquid
Has dark, wet, or sunken spots
Looks shriveled, dried out, or heavily wrinkled
Has a fermented or off taste
Shows brown or translucent flesh throughout
Has a crown that is brown, dry, or easily pulls out
Feels unusually light for its size
Has a strong rotten odor near the base