How to Tell If Food Has Gone Bad
- 3 cited USDA/FDA/FSIS sources
- Content updated 2026-09-23
Exact references cover 1 of 5 detected claims in the English guide. The remaining statements have not completed exact-source review. References alone do not confirm every claim; normal smell or appearance does not prove safety.
Visible spoilage is a reason to discard food. But food can cause illness even when it looks, smells, and tastes normal. Do not use sensory checks to establish safety; check storage temperature, handling, and time instead.
Smell
Sour, putrid, ammonia-like, or “off” odors on meat, dairy, and seafood are strong discard signals. However, Salmonella and other pathogens do not always change how chicken smells — never use smell alone for raw poultry.
Texture and appearance
- Slime on meat or fish — discard.
- Mold on soft foods (berries, bread, soft cheese) — discard the item; do not trim and eat.
- Discoloration — gray-green patches on meat, pink slime on lunch meat, or dull, mushy produce.
- Curdled or lumpy milk and separated, watery yogurt.
When sensory checks fail
Cooked food left in the danger zone (40°F–140°F) for more than 2 hours should be discarded even if it looks fine. Bacteria such as Staphylococcus aureus can produce toxins that reheating does not destroy.
Use our food pages
Food pages describe item-specific signs and storage windows. Each storage card shows whether its interval has an exact source match or remains an editorial estimate.
Related on FoodLasts
Guides: Mold on produce · Date labels explained
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Sources: FoodSafety.gov — Keep Food Safe , USDA FSIS — Danger Zone (40°F – 140°F) , FDA — Are You Storing Food Safely? . Content updated 2026-09-23. See the exact-source coverage above.