12 Signs Your Seafood Isn't Fresh, According To An Executive Chef

Nothing ruins a dining experience more than subpar seafood. Imagine a fishy smell, rubbery texture, or pungent flavor. It all sounds like an unwelcome attack on the senses, but luckily, this can be avoided with the right knowledge. The key is looking for signs that your seafood isn't fresh. And to help us identify these red flags, we turned to Mazen Mustafa, executive chef at The Lonely Oyster.

Mustafa is familiar with buying fresh seafood as well as preparing seafood dishes at The Lonely Oyster, a Los Angeles oyster bar serving everything from lobster rolls to tuna tartar. As such, many of these red flags can be applied to both fresh seafood purchases and restaurant orders. Because however you get your seafood, quality is essential — and freshness is a big part of that. It isn't solely about taste considerations, either. If seafood isn't fresh, it can harbor harmful pathogens that pose genuine health risks.

Becoming seafood savvy is a beneficial skill. Who wants to throw money away because they couldn't tell the difference between delicious and denatured fish? Not only will it enhance your dining experience, but it may also improve your well-being. So if you want to navigate the murky waters of seafood selection with confidence, look out for these signs your seafood isn't fresh.

Ammonia has an undeniable smell reminiscent of human urine or cleaning products. It's far from appetizing, and it seems obvious that if your seafood smells like this potent chemical, you should steer clear. But what makes seafood smell like ammonia, and is it actually dangerous or simply off-putting?

Mustafa explains that when fish decay, a bacteria called trimethylamine (TMA) is released from the tissues. In small quantities, this organic compound smells slightly fishy, but in larger amounts, TMA begins to smell like ammonia. When it comes to fresh seafood, he notes, "Everything should smell like fresh ocean mist." A slight brininess is okay, but an overly fishy or ammonia odor is a sign of too much TMA, meaning your seafood is rotten.

This rule can apply to both fresh and cooked seafood. So if you sit down at a restaurant and your filet smells far too fishy, it's a telltale sign that your fish has gone bad. But if your seafood is undeniably fresh and you simply don't like that ocean smell, try squeezing fresh lemon over your dish. Citrus has a way of balancing that briny odor and bringing out brighter flavors.

When we think of the freshest seafood out there, we think of beachside fishmongers with beautiful spreads. Everything looks like it was caught that morning, and that's exactly what you should aim for in texture. When purchasing raw seafood, Mustafa says, "It should look like it was just pulled from the line." Of course, we aren't all lucky enough to live by the water, and this level of freshness isn't always attainable. So, if you question the freshness of your seafood, there are some textural warning signs to look out for.

When seafood has gone off, Mustafa warns that "the flesh becomes soft and slimy." This applies to a variety of seafood, including fish and crustaceans. However, he singles out lobster, explaining that old lobster "will be flaccid or saggy." You see, like most whole foods, seafood is perishable. It begins decaying the second it dies. When this happens, naturally occurring enzymes break down the seafood's tissue, particularly the muscle. This causes the seafood to soften. The more time passes, the softer this flesh becomes, and the higher the risk of bacteria. So if you notice your seafood's texture is just sad and floppy, give it a pass.

An overly soft or slimy texture isn't the only warning sign of bad seafood. You should also pay attention to the integrity of the muscle fibers. When seafood is alive, its muscles are tight. If you look at freshly caught raw salmon or tuna, you'll notice distinct but firm lines. If they begin to separate, the decaying process is well underway. And if chunks are chipping off, you're dealing with second-rate seafood.

Although less obvious, scallops also have a taught muscle structure. If you break a raw scallop in two, the muscle fibers should be extremely compact. Fibers that are more spread apart mean your scallops aren't super fresh. They may still be safe to eat, but the flavor and texture will be compromised. Separated fibers can be a sign of age or mishandling, but to truly know if your seafood is off, we'd look at the muscle fibers in combination with other factors like smell, texture, and color.

Color may be one the easiest indicators of spoiled seafood, but of course, a healthy color depends on seafood variety as well as whether it's raw or cooked. For starters, scallops can vary slightly in color, with males being whiter and females being a richer yellow or slightly pink. If scallops have been treated with sodium triphosphate (STPP), they'll be a bleached translucent white, wet, and super plump. But while STPP may preserve seafood's shelf life, many believe it takes away from the natural fresh flavors and texture.

When it comes to fish, raw tuna is naturally a deep red when fresh. However, if it's treated with carbon monoxide to prevent browning, it'll be a bright pink. Mind you, this treatment only prevents the color from changing; it doesn't prevent the fish from going bad. As such, this pink color doesn't necessarily mean it's fresh. Meanwhile, most raw salmon will be a rich pink. How do these colors change when cooked? "Most fishes should be lighter in color or more opaque after cooking," Mustafa explains. "You can often see a translucent rainbow coloring through the fish fats as they melt with temperature."

When it comes to shrimp, the raw stuff should be a translucent shade of gray or pink. Like fish, shrimp will turn opaque when cooked. It should have a pretty pink exterior, red tails, and whitish flesh. So how do you tell if your shrimp has gone bad before cooking? Mustafa says, "The head will start to darken." But generally speaking, any abnormal color for raw or cooked seafood should be questioned.

If you visit the fishmonger or the fish aisle of your local grocery store, fresh seafood may be displayed on ice — which is a good thing. It needs to be kept at a cold temperature to stay fresh. However, if the fish itself is developing ice crystals, we'd think twice before purchasing. As Mustafa explains, "[this is] freezer burn and indicates the product was not stored or packaged properly." This is especially important to look out for when purchasing frozen seafood since Mustafa adds that freezer burn "will dramatically impact the flavor profile." Although freezer burn isn't a safety issue, it definitely affects freshness.

If you've already purchased seafood and plan to freeze it, avoid making common food storage mistakes. To prevent freezer burn, make sure you seal your fish in an airtight package. Keep your freezer at the appropriate temperature, and try not to leave it open too long when fishing for items in the back. Lastly, don't thaw and refreeze your seafood — once defrosted, savor it all so it doesn't lose flavor.

Freezing and defrosting seafood multiple times is a bad idea. But even if you aren't freezing your seafood, you should keep it consistently cold before cooking. If seafood is kept at a warmer temperature, it risks entering the "Danger Zone," a temperature range of 40 F to 140 F in which bacteria multiply at alarming rates. If you're purchasing seafood, make sure it's been kept at the appropriate temperature. If you're eating at a seafood buffet, hot dishes should be kept in warming trays or under heating lamps, and raw seafood should be on ice.

There have been numerous seafood recalls that affected millions over the years, many of which stemmed from bacteria. Think salmonella, listeria, norovirus, and vibrio. Raw seafood comes with an increased risk of infection, which is why people wonder whether we should be eating raw oysters at all. The European Food Safety Authority has even warned consumers that vibrio — a bacteria that can cause severe food poisoning — is on the rise in aquatic animals like oysters. However, when mollusks are kept at cold temperatures, this risk significantly decreases. We're not about to give up our tasty raw oysters. So, to limit food-borne illnesses, keep a watchful eye on the temperatures and storage of seafood, particularly when served raw.

This red flag might seem obvious to some, while others will think, well, they're going to die anyway, so what's the issue? The issue is that dead lobsters and crabs in a tank are never a good sign. For the freshest flavor, you want to cook a lobster when it's alive. Many seafood stores claim you can safely consume lobster 12 to 24 hours after death. But even so, dead lobsters should never be floating around in the tank.

Firstly, you don't know how long the dead carcasses have been there. If staff isn't watching the tank, who knows what other corners they're cutting. Plus, the longer dead crustaceans hang around, the more likely they are to leach harmful bacteria into the tank. As mentioned, seafood begins decaying the second it dies, so if that seafood is lingering near live creatures, they'll be exposed to the bacteria, as well.

If you visit a fish market or restaurant with a tank, don't be afraid to examine it and keep your eyes peeled for one of the telltale signs a lobster is dead. Tails and appendages may become loose while claws remain clenched, and the shell or eyes may take on a dull color, which should be easy to spot next to the more vibrant live creatures.

Buying whole fish comes with several benefits. Not only does it reduce waste, but you can get a better deal on whole fish as opposed to filets. Plus, the fishmonger can remove entrails and scales for you if asked, so you're left with all the tasty bits, like the nutrient-rich skin and protein-packed flesh. However, if you're purchasing an entire fish, there are some telltale signs of spoilage to watch out for.

Mustafa shares some of these red flags, which include obvious signs of discoloration. "The eyes are not clear, or the gills are dark." He also describes how if you touch fish skin and "it doesn't bounce back to its original form," it's likely gone bad. The fish may even have developed belly burn, which is soft, grayish interior meat caused by enzyme breakdown. To avoid these issues, keep your eyes peeled for the freshest whole fish options. The fish should have shiny skin, firm flesh, and clear, bulging eyes. It should also have red or pink gills and tightly attached scales.

Bivalves are a type of mollusk containing a body enclosed in a hinged shell. These include popular kinds of seafood like clams, mussels, and oysters. But if you've ever gotten food poisoning from one of these shellfish, it's a hard feeling to shake. Even if you love seafood, one bad experience can put you off bivalves faster than you can say "sea-ya!" But before you completely bid farewell to these delicious delicacies, there are ways to tell if you're dealing with fresh or spoiled bivalves before cooking.

As Mustafa shares, "Bivalves open when they start to turn, so this is a major indicator." Mind you, shellfish do open and close when alive, and if you're soaking or rinsing clams, you can expect them to open their shells. However, if you're purchasing shellfish at the market and want to know if they're alive or dead, just give them a slight tap. They should clam right up (pun intended). If they don't close, they're likely dead, in which case you should avoid eating them. Dead shellfish can multiply bacteria quickly, presenting a significant health risk.

Whether buying fish fresh from the market or ordering a cooked seafood meal, an empty seafood establishment should immediately raise red flags. After all, seafood has a limited shelf life. And if a fishmonger consistently lacks customers, they likely aren't receiving regular deliveries and may keep inventory hanging around longer than ideal. If you want the freshest catch, we recommend talking to the fishmonger directly and keeping an open mind. Also, one of the biggest mistakes you can make when buying fish at the grocery store is pigeonholing yourself with one type of seafood. Perhaps you have your heart set on salmon, but if the fillets aren't fresh, don't be afraid to try another fish altogether.

In seafood restaurants, empty tables suggest that locals — who know the best spots – avoid eating there. Unfortunately, this creates a dangerous cycle of fewer customers, leading to slower inventory turnover. Without steady business, establishments may take shortcuts, like serving seafood past its prime or freezing and thawing products. And ultimately, this means that the seafood platter you ordered won't be super fresh.

Finding the best catch means seeking out quality vendors. The freshest seafood suppliers and restaurants are often found where there's consistent demand and rapid turnover. Think busy fish markets in the morning or seafood restaurants with a steady stream of loyal patrons. If you're uncertain, check reviews on Yelp or Google Maps before ordering.

The seafood you bought on Monday? If it's still sitting in your fridge on Friday, we'd think twice before cooking it. According to the USDA, raw seafood should only be kept in the refrigerator for one to two days, while cooked seafood can last safely up to four days. This short time frame might seem surprising, but considering that seafood has a higher pH and water content than meat, it makes sense that it spoils faster.

Restaurants keep their fish fresh as long as possible by storing it at temperatures below 38 F. If your fridge isn't this cold or you don't plan to eat your seafood right away, consider freezing it instead. The USDA recommends using fish within three to eight months of freezing, raw shellfish within three to 12 months, and cooked fish within three months. However, it's important to note that while freezing keeps seafood safe for longer periods, the freshness will gradually decline.

Is the date printed on your seafood packaging a hard rule or merely a suggestion? Surprisingly, the USDA says the latter. It turns out those 'best-by' and 'use-by' dates are more about quality control than safety. But just because you can technically eat seafood past its expiration date doesn't mean you should. The older the seafood, the less fresh it'll be.

We recommend checking the quality of your expired seafood before consumption. Even if it's well before that 'best-by' date, we still recommend examining your seafood for red flags since improperly packaged or stored seafood will spoil far sooner. Look for suspicious smells, textures, or other items mentioned on this list.

If you're skeptical, read our guide to food expiration dates. You'll see that while these dates aren't a hard-and-fast rule, they exist for a reason. Seafood has a limited shelf life, and the risk of harmful pathogens tends to increase as the quality of seafood declines. So when in doubt, throw it out! You'll get over the disappointment of discarding seafood faster than you will food poisoning.