You can usually tell if salmon is bad by checking date, smell, look, and texture, and if you’re ever unsure, it’s safest to throw it out.

Quick Scoop

1. First check: dates and storage

  • If the “use by” or “sell by” date is past, don’t risk it; just toss it.
  • If it sat at room temperature for more than about 2 hours (or 1 hour on a very hot day), it may no longer be safe, even if it looks okay.
  • Thawed salmon that’s been in the fridge more than 1–2 days after thawing is “borderline”; combine time with the signs below and be conservative.

2. Smell: the biggest red flag

Fresh salmon should smell mild, clean, and a bit like the ocean, not “fishy.”

Bad or risky salmon often smells:

  • Strongly fishy or “funky”
  • Sour or vinegary
  • Like ammonia or cleaning chemicals

If the smell makes you hesitate or think “ugh,” don’t eat it.

3. Appearance: color and surface

For raw fillets:

  • Healthy look: bright, even pink‑to‑orange color, no dark or dry edges, no odd patches.
  • Bad signs:
    • Dull, grayish, or brown patches/spots on the flesh
* Filmy white, milky, or opaque coating on the surface (different from the white protein that appears when cooking)

* Obvious mold or any fuzzy growth

For whole salmon:

  • Healthy look: clear, bright eyes, shiny skin, and bright red gills.
  • Bad signs: cloudy or sunken eyes, faded or brownish gills, dull skin.

4. Texture: how it feels when you touch it

  • Fresh salmon feels firm and slightly springy; when you press it gently, it should bounce back.
  • Bad or borderline salmon may be:
    • Mushy or “mashy” when pressed
    • Slimy, sticky, or tacky on the surface instead of just moist
* So soft that your finger leaves an indent that doesn’t spring back

If it feels like it’s starting to melt or smear instead of staying in neat flakes, that’s a bad sign.

5. Cooked salmon: what to look for

Cooked salmon doesn’t last long either, even in the fridge.

  • Normal: moist but firm flakes, pleasant, mild smell.
  • Bad signs:
    • Sour or rancid smell
    • Slimy surface or obvious drying plus strange spots
    • Taste that seems bitter, sour, or “off” (if you notice this after one bite, stop eating)

If cooked salmon has been in the fridge for more than about 3–4 days, it’s safer to throw it away.

6. Why eating bad salmon matters

Spoiled salmon can carry bacteria like Salmonella, Clostridium botulinum, and Staphylococcus aureus, which can cause food poisoning.

Possible symptoms include:

  • Stomach cramps
  • Nausea and vomiting
  • Diarrhea
  • Headache and fever

These can be especially serious for children, older adults, pregnant people, and anyone with a weakened immune system.

7. Quick yes/no checklist

Ask yourself:

  1. Does it smell neutral and mild, not sour, fishy, or like ammonia? If no → toss.
  2. Is the color bright and even, without gray/brown patches or milky slime? If no → toss.
  3. Is the texture firm and moist, not mushy, sticky, or slimy? If no → toss.
  4. Is it within the labeled date and stored cold the whole time? If no or unsure → toss.

If you get even one strong “this seems wrong” signal, the safest move is to bin it. Food poisoning costs way more (in time and misery) than a piece of fish.

TL;DR: If the salmon smells strong or sour, looks dull or slimy, or feels mushy or sticky, don’t eat it—when in doubt, throw it out.

Information gathered from public forums or data available on the internet and portrayed here.