How to Tell If Salmon Is Bad (3 Ways)

Published Categorized as Food
VALENTYN VOLKOV

Stay safe! We’ve got the scoop on how to tell if your salmon filets have gone bad and may no longer be edible.

Salmon is a fish that’s at its best the moment you buy it from the fishmonger or seafood counter at your grocery store. From that moment on, it slowly but surely loses quality until you cook and eat it.

Refrigerate or freeze the salmon as soon as you get it home. As American culinary author Harold McGee writes in Keys to Good Cooking, salmon—a cold-water fish—has the shortest shelf life of all fishes.

The best way to store salmon isn’t to store it at all, and instead cook it the same day you bought it. In case this isn’t possible, bear in mind that salmon can be kept in the fridge for 1-2 days raw and 3-4 days cooked.

If you’ve kept salmon longer, or you suspect that it’s spoiled, throw it away and don’t eat it. Although the bacteria that spoil food are usually harmless, by the time the fish has spoiled, it may be overgrown with disease-causing bacteria.

When in doubt, see our guide below.

Ways to Tell If Salmon Has Gone Bad

If you have kept raw salmon in the refrigerator for more than 1-2 days or cooked salmon for more than 3-4 days, you should assume that it’s no longer safe to eat and discard it.

If you don’t remember when you brought the salmon back home, or someone else in your household bought it, watch for signs that it may already be spoiled. Salmon is bad if it smells excessively fishy, its flesh turns gray, and its skin gets covered with yellowish slime. Bad salmon is also sticky, slimy, and mushy to the touch.

Give It a Sniff

Take the fish in your hands, hold it to your nose, and sniff it inquisitively. Does it smell off to you?

Fresh salmon has almost no odor. When you sniff it, it should remind you of the Atlantic Ocean, the East Coast seashore, or cold-running river water. You may pick up briny and creamy notes, but you should smell nothing fishy.

The longer the salmon sits, the more time the bacteria and enzymes that live on its skin have to convert the amino acids contained in it into trimethylamine, an odorous substance that gives it a fishy smell. This fishy smell is a sign of age, not naturalness.

If the salmon smells slightly fishy, it may still be good, and this smell can be washed away by the obligatory rinsing before cooking. But if it smells too fishy and repulsive, then it’s already gone bad.

Look at the Flesh

Fresh salmon filets should be a gorgeous shade of pink to orange, depending on the variety. The colors of farmed salmon are plain and pale, while those of wild-caught salmon are rich and vibrant.

Salmon filets that have gone bad have a dull and gray color. When the filets can no longer hold their shape and the flakes only loosely hang on to each other, the salmon is no longer tasty and may no longer be safe.

Turn the salmon filets over and examine the skin. If the skin looks wet, as if the salmon was just caught in cold water, the filets are fresh. If the skin looks gooey and covered with yellowish slime, the filets are old.

Touch It

Last but not least, there’s the touch test. Prick the salmon with the index finger of your dominant hand. You’re looking for two signs.

If the salmon filets are still fresh, the flesh should feel clean and slightly creamy. When they are spoiled, they are sticky and slimy, making you raise your eyebrows and prompting you to compulsively wash your hands.

If the filets are lively and springy, they are fresh. If they are lifeless and mushy, they are long past their prime and may be inedible.

Will Cooking Spoiled Salmon Make It Safe?

No, reheating or cooking spoiled salmon won’t make it any safer to eat.

This is a dangerous misconception that can lead to food poisoning, especially for the young, the pregnant, the elderly, and those with a compromised immune system.

Prolonged exposure to high heat will kill most, if not all, of the disease-causing bacteria in the fish. However, it won’t get rid of the heat-resistant toxins that these bacteria have left behind in it.

Few people realize that these toxins can cause foodborne illnesses as bad as the pathogens that created them in the first place. This is something that is taught in culinary school but rarely passed on to home cooks by celebrity chefs and cookbook authors.

If It Smells and Tastes Fine, Can I Still Eat It?

The problem with eating food that you have kept too long—salmon being no exception—is that you have no way of knowing if it’s still safe. A salmon filet can smell and taste perfectly fine, but still cause food poisoning.

We can easily recognize the bacteria, fungi, and yeasts that spoil our food because they make it smell bad, feel nasty, and taste disgusting. But the pathogenic bacteria that cause food poisoning aren’t detectable to us; they don’t affect the smell, taste, or texture of our food.

The short answer is no. If you have kept the salmon too long, but it still smells and tastes good, you can still get sick from eating it.

Always play it safe when it comes to the food you serve on the table. In the U.S. alone, the Centers for Disease Control and Prevention (CDC) estimates that 48 million people get food poisoning, 128,000 get hospitalized, and 3,000 die each year.

Bacteria grow fastest at room temperature, slower in the fridge, and go into hibernation in the freezer. This is why salmon, raw or cooked, should always be refrigerated and never be left to sit out at room temperature for longer than 1-2 hours. The hotter the weather, the shorter its shelf life.

It’s also why salmon lasts 1-2 days in the fridge raw, 3-4 days in the fridge cooked, and, technically, stays safe to eat in the freezer forever. (Although frozen salmon will dry out and lose much of its original appeal over time, which is why every website on the Internet gives you storage times “for best quality.”)

In Conclusion

Buy your salmon fresh and prepare it the same day. If that’s not possible, refrigerate it and cook it within 1-2 days. When in doubt, watch for the tell-tale signs of spoilage: fishy odor, gray color, slimy and mushy consistency.

By Jim Stonos

When Jim isn't in the kitchen, he is usually spending time with family and friends, and working with the HCW editorial team to answer the questions he used to ask himself back when he was learning the ropes of cooking.