Spotting Bad Fish Fillets: Sammy’s Tips for Freshness

Alright folks, Sammy here, your friendly neighborhood food enthusiast from Chefsicon.com. Today, we’re diving deep – pun absolutely intended – into a topic that can make or break your dinner plans: how to avoid bad fish fillets. There’s nothing quite like the anticipation of a beautifully cooked piece of fish, flaky, moist, and flavorful. And conversely, there’s nothing quite as disappointing, or frankly, sometimes worrying, as realizing the fillet you so carefully selected is… well, less than stellar. It’s happened to the best of us, myself included, more times than I’d care to admit in my early culinary adventures. I remember one time, back when I first moved to Nashville from the Bay Area (where, let’s be honest, fresh seafood was practically jumping onto your plate), I bought some cod that looked okay-ish under the supermarket lights. Got it home, and Luna, my usually food-obsessed rescue cat, wouldn’t even sniff it. That should have been my first clue! Needless to say, that meal was a write-off. But those experiences are learning opportunities, right? So, today I want to share what I’ve learned over the years, blending a bit of food science with practical, on-the-ground tips you can use whether you’re at a fancy fishmonger or your local grocery store. We’re going to cover everything from deciphering what ‘fresh’ truly means to trusting your senses and making informed choices. By the end of this, you’ll be a fish-selecting savant, I promise. Or at least, you’ll significantly reduce your chances of that fishy letdown.

The quest for the perfect fish fillet isn’t just about taste; it’s about safety and getting the most value for your money. Fish is a fantastic source of protein and healthy fats, but it’s also highly perishable. Understanding its journey from water to your plate is key. It’s a bit like marketing, actually – you need to look past the flashy packaging or the enticing display and really scrutinize the product itself, understand its provenance. Is this the best approach? Maybe not for everything in life, but for fish, a little skepticism and a lot of knowledge go a long way. We’ll explore the visual cues, the olfactory signals (yes, you gotta smell it!), the textural tells, and even the questions you should be asking your fishmonger. It’s about becoming an empowered consumer, not just a passive buyer. I used to just grab whatever looked white and vaguely fish-shaped. Now? Now, I’m practically interrogating the fish counter staff. In a friendly way, of course.

Think of this as your personal guide, compiled from years of experience, a few unfortunate meals, and a genuine desire to help you enjoy fish the way it’s meant to be enjoyed. We’ll talk about fresh versus frozen (spoiler: frozen isn’t always the villain it’s made out to be), how to store fish correctly once you get it home, and those critical red flags that scream “Do not eat!” No more guessing games, no more hoping for the best. We’re aiming for consistent, delicious results. Because life’s too short for bad fish, plain and simple. And honestly, with the insights we’re about to unpack, you’ll find that sourcing excellent fish fillets becomes second nature, almost an instinct. It’s about tuning into the subtle language of the product itself. So grab a coffee, maybe a notepad, and let’s get to it. Luna is currently napping on my notes, which I take as a sign of approval for this topic. Or she’s just being a cat. Probably the latter.

Unmasking the Culprits: Your Guide to Pristine Fish Fillets

1. Understanding “Freshness” in Fish: More Than Just a Date Stamp

So, what does “fresh fish” actually mean? It’s a term thrown around a lot, often quite loosely. For many, it conjures images of fish pulled from the water mere hours ago. While that’s the ideal, it’s not always the reality, especially for those of us not living right on the coast. The first thing to understand is that “fresh” in a retail context usually means the fish has never been frozen. That’s it. It doesn’t necessarily tell you how long ago it was caught, or how well it’s been handled since. Fish begins to deteriorate the moment it leaves the water due to enzymatic action within its own flesh and bacterial growth on its surfaces. Think about it: the fish’s natural enzymes, designed for digestion and other life processes, don’t just switch off upon death. They start breaking down the muscle tissue, leading to changes in texture and flavor. This process is accelerated by warmer temperatures. Then there are the bacteria, naturally present on the fish’s skin, gills, and in its gut. Once the fish dies, these bacteria can multiply rapidly, especially if the fish isn’t gutted and chilled promptly. This is why proper handling immediately after catching is so crucial. Rapid chilling to near-freezing temperatures (around 30-32°F or -1 to 0°C) is paramount to slow down both enzymatic decay and bacterial growth. A “sell-by” date is a guideline for the store, not a definitive guarantee of freshness for you, the consumer. It’s a piece of the puzzle, but not the whole picture. I often find myself wondering if the systems in place are truly optimized for the end consumer’s experience or just for logistical ease. It’s a complex chain, and somewhere along it, information can get muddled.

You might also hear about rigor mortis in fish. Just like in mammals, fish muscles stiffen after death. The onset and duration of rigor mortis can actually be an indicator of freshness and handling. Fish that enters rigor quickly and stays in it for a longer period is generally of better quality, as this indicates it was healthy and not stressed before being caught, and was chilled rapidly. Once rigor passes, the flesh begins to soften, and this is when the enzymatic and bacterial degradation really kicks into gear if conditions aren’t optimal. So, a very fresh fish might still be quite stiff or just coming out of rigor. However, a fillet that’s overly soft or limp and shows no signs of ever having been firm is a cause for concern. It’s a delicate balance, and understanding these natural processes helps you interpret what you’re seeing and feeling at the fish counter. It’s not just about avoiding ‘bad’ fish, it’s about aiming for ‘peak quality’ fish. There’s a difference, and your palate will thank you for recognizing it. I remember learning this and it was a bit of an ‘aha!’ moment, suddenly the slight variations I’d noticed in texture made so much more sense.

2. The Eyes Have It (And So Does the Nose): Visual and Olfactory Cues

This is where your senses become your most powerful tools. Let’s start with the eyes, if you’re buying a whole fish (which often gives you the best clues). The eyes should be clear, bright, and slightly bulging. Think of a healthy, live fish – that’s the look you want. Cloudy, sunken, or opaque eyes are a dead giveaway (pun intended, again, sorry!) that the fish has been out of the water for too long and is well past its prime. The cloudiness is due to the deterioration of the cornea and fluids within the eye. It’s a pretty reliable indicator. If you’re looking at fillets, you won’t have eyes to guide you, but there are still plenty of visual cues. The flesh itself should look moist and translucent, or if it’s an oilier fish like salmon, it should have a vibrant, rich color. Avoid fillets that look dull, dry, or have a chalky appearance. Any browning or yellowing around the edges of a white fillet is a bad sign, indicating oxidation and spoilage. Similarly, if the color looks faded or washed out, it could mean the fish is old or has been improperly handled, perhaps exposed to too much air or light. Pay attention to any liquid in the package or on the display tray. A little clear moisture is normal, but if the fish is swimming in milky or cloudy liquid, steer clear. That’s often a sign of cells breaking down and bacteria having a party. It’s like looking at a product’s packaging in marketing – sometimes what’s NOT there tells you more than what is. The absence of vibrant color can be a big warning.

Now, let’s talk about the nose. This is arguably the most important test. Fresh fish should smell like the ocean, clean and briny, perhaps with a hint of seaweed. It should not have a strong, overpowering “fishy” odor. That distinctively unpleasant, ammonia-like, or sour smell is a clear indication of spoilage, caused by the breakdown of amino acids by bacteria, producing compounds like trimethylamine (TMA). If you get a whiff of anything that makes you recoil even slightly, trust your instinct and walk away. Don’t be shy about asking to smell the fish, especially if it’s behind a counter. A good fishmonger will have no problem with this; in fact, they should encourage it. If they seem hesitant or refuse, that itself is a red flag. I’ve definitely been in situations where I’ve politely asked for a sniff and the reaction told me everything I needed to know before my nose even got close. Remember, by the time fish develops a really foul odor, it’s usually well past the point of being safe or pleasant to eat. Sometimes the smell can be subtle at first, so really take a moment. Is it clean and oceanic, or is there an underlying note of something…off? This skill takes a little practice, but once you learn to distinguish good from bad, it’s invaluable. Luna, my cat, has an unerring nose for this. If I bring home fish and she turns her nose up, I immediately get suspicious. She’s my furry little quality control expert.

3. Feel Factor: Texture and Firmness of a Good Fillet

Beyond sight and smell, touch is another crucial sense in evaluating fish fillets. If you’re allowed to (and sometimes you can, especially with a good fishmonger or if the fish is pre-packaged in a way you can gently press it), the flesh should feel firm and elastic. When you press it gently with your finger, it should spring back, leaving no indentation. If your finger leaves a dent, or if the flesh feels soft, mushy, or slimy, that’s a strong indicator that the fish is old and its cellular structure has started to break down significantly. This breakdown is due to those enzymes and bacteria we talked about earlier, which weaken the muscle fibers and connective tissues. A slimy surface is also a major warning sign. While fresh fish will naturally have a thin, clear layer of slime (its natural protective coating), an excessive, thick, or milky slime is a sign of bacterial overgrowth and spoilage. It’s like the difference between dewy skin and, well, something less pleasant. You want that resilience, that bounce-back. It’s an indicator of structural integrity, which directly correlates with freshness.

Also, pay attention to how the fillets are holding together. If the flesh is starting to separate or flake apart easily while still raw (a phenomenon sometimes called “gaping”), it could be a sign of age, rough handling, or even previous freezing and improper thawing. While some delicate fish might be more prone to this, significant gaping in a fillet that should be firm is generally not a good sign. The muscle segments (myotomes) should be tightly connected. When they start to pull apart, it suggests the connective tissue (myocommata) is degrading. This is a subtle point, and one I didn’t appreciate until I started looking really closely. It’s easy to overlook if you’re in a hurry. But these little details, they add up. It’s like analyzing data in a marketing campaign; individual data points might not tell you much, but patterns emerge when you look at them together. A slightly off smell, plus a bit of dullness, plus a soft texture? That’s a clear pattern of a fish past its best.

4. Source Matters: Where You Buy Your Fish Makes a Difference

This might seem obvious, but it bears repeating: where you buy your fish fillets can significantly impact their quality. A reputable fishmonger who has a high turnover, knowledgeable staff, and a clean, well-maintained display is often your best bet. They are more likely to have established relationships with good suppliers and understand the importance of proper handling and storage. Don’t hesitate to ask questions: When did this fish come in? Where is it from? How was it caught? A good fishmonger will be happy to share this information. Their willingness to engage and provide details is often a sign of confidence in their product. I’ve found that building a relationship with a local fishmonger can be incredibly rewarding. They get to know your preferences and might even give you a heads-up when something exceptionally fresh arrives. It’s like having an inside source. When I moved to Nashville, finding a good fishmonger was one of my top priorities. It took some trial and error, but now I have a couple of trusted spots.

Supermarkets can be more of a mixed bag. Some have excellent seafood departments with well-trained staff and high standards, while others… not so much. Look for the same signs: cleanliness, clear labeling, and staff who can answer your questions. Pay attention to how the fish is displayed. Is it piled high, or is it laid out in a single layer on a thick bed of ice? Fish should be kept well-chilled, ideally surrounded by ice, not just sitting on top of a refrigerated shelf. The ice helps maintain a consistent low temperature and also helps to keep the fish moist. If the fish looks like it’s been sitting there for a while, or if the ice looks old and melted, it’s probably best to pass. Online fish suppliers are also an option, and some are excellent, shipping fresh or flash-frozen fish directly to your door. If you go this route, research the company thoroughly, read reviews, and understand their shipping and handling practices. They should be able to guarantee that the fish will arrive at a safe temperature. Ultimately, it’s about due diligence. No matter where you shop, be an observant and inquisitive customer. Your diligence is your first line of defense against bad fillets.

5. Decoding Labels: Wild-Caught vs. Farm-Raised, Sustainability, and More

The labels on fish can be a bit of a minefield, but they can also offer valuable clues if you know what to look for. Wild-caught vs. farm-raised is a common distinction. Neither is inherently superior in all cases; it really depends on the species, the specific fishery, or the aquaculture practices. Wild-caught fish often have a more complex flavor and firmer texture due to their natural diet and activity levels. However, sustainability can be a concern for some wild species due to overfishing. Look for certifications like the Marine Stewardship Council (MSC) blue label, which indicates that the wild fish comes from a fishery that meets standards for sustainable fishing. Farm-raised fish (aquaculture) can be a sustainable alternative for some species and can offer a consistent supply. However, the quality of farm-raised fish can vary widely depending on the farming methods, feed quality, and environmental standards. Look for certifications from organizations like the Aquaculture Stewardship Council (ASC) or Best Aquaculture Practices (BAP). These labels can provide some assurance about responsible farming practices. I’m always a bit torn here, because the ideal is wild, perfectly sustained, but the reality of feeding a large population makes responsible aquaculture so important. It’s a complex system, and as consumers, our choices do send signals.

Beyond these basic labels, you might also see terms like “fresh frozen,” “previously frozen,” or “Product of [Country].” “Fresh frozen” or “flash frozen” usually means the fish was frozen very quickly after being caught, often on the fishing vessel itself. This method can preserve the quality very well, sometimes even better than so-called “fresh” fish that has taken a long time to reach the market. “Previously frozen” means the fish was frozen and then thawed for sale. There’s nothing inherently wrong with this, as long as it was handled correctly during both freezing and thawing. However, you should use previously frozen fish quickly and generally avoid refreezing it. The country of origin can also be relevant, as handling standards and regulations can vary. It’s not always a direct indicator of quality, but it can be a factor to consider, especially if you have concerns about specific regions or fishing practices. The key is to be an informed consumer. Don’t just glance at the price tag; take a moment to read and understand the information provided. It’s another layer of your defense against subpar fish. It feels a bit like detective work sometimes, doesn’t it? Piecing together clues to make the best choice.

6. Frozen Fish Fillets: Not Always a Second-Best Option

Let’s talk about the often-maligned frozen fish fillet. There’s a common misconception that frozen fish is always inferior to fresh. But that’s not necessarily true. In fact, properly frozen fish can be of excellent quality, sometimes even better than fresh fish that has endured a long and uncertain journey to your local market. The key is how it’s frozen and how it’s handled. Fish that is “flash-frozen” at sea, shortly after being caught, undergoes rapid freezing at very low temperatures. This process minimizes the formation of large ice crystals within the fish’s cells, which can damage the texture and cause moisture loss upon thawing. When done correctly, flash-freezing locks in the freshness and flavor of the fish at its peak. So, if you don’t have access to genuinely fresh, recently caught fish, high-quality frozen fillets can be a fantastic alternative. I often keep a stash of good quality frozen salmon or cod fillets in my freezer for quick and healthy meals. It’s a lifesaver on busy weeknights.

When buying frozen fish, look for fillets that are solidly frozen, with no signs of thawing and refreezing. The packaging should be intact and airtight. Avoid packages with a lot of ice crystals inside the bag (frost or freezer burn), as this can indicate temperature fluctuations during storage, which can negatively affect the texture and flavor of the fish. Freezer burn appears as dry, discolored patches on the surface of the fish and means moisture has been lost. The fish should also be free of any off-odors once thawed – it should still smell clean and fresh. Proper thawing is also crucial for maintaining the quality of frozen fish. The best way to thaw is slowly, in the refrigerator, over 24 hours. Avoid thawing at room temperature, as this can allow bacteria to multiply on the surface while the inside is still frozen. If you’re in a hurry, you can thaw sealed fish under cold running water. Once thawed, cook the fish promptly. And generally, it’s best not to refreeze fish that has been fully thawed, as this can further degrade its quality. Maybe I should clarify: if it’s partially thawed but still has ice crystals, refreezing is usually okay, but fully thawed? Best to cook it.

7. Common Types of Spoilage and What They Mean

Understanding a little about what actually goes wrong when fish spoils can make you a more discerning buyer. The primary culprits are bacterial spoilage and enzymatic degradation. As we’ve touched on, bacteria are naturally present on fish, and they multiply rapidly in warmer temperatures, breaking down the fish’s tissues and producing those tell-tale off-odors and slimy textures. Different types of bacteria thrive at different temperatures, but keeping fish consistently cold (just above freezing) is the best defense. Enzymes native to the fish also contribute to spoilage by breaking down proteins and fats, leading to mushiness and rancid flavors, especially in oily fish if they are not handled well. This is why quick gutting and chilling are so critical right after the catch. The fish’s own internal organs are a major source of both enzymes and bacteria that can accelerate spoilage if not removed promptly.

Another issue, particularly with certain types of fish like tuna, mackerel, mahi-mahi, and bluefish, is histamine formation, also known as scombroid poisoning. If these fish are not chilled properly after being caught, bacteria can convert an amino acid called histidine (naturally present in the fish’s flesh) into histamine. Consuming fish with high levels of histamine can cause an allergic-type reaction with symptoms like rash, flushing, headache, dizziness, and gastrointestinal upset. Histamine is not destroyed by cooking, so prevention through proper chilling is key. This is why trusting your source and their handling practices is so important, especially for these species. While less common in commercially sold fillets from reputable sources, parasites like worms (nematodes) can sometimes be found in fish. Most are killed by thorough cooking or commercial freezing (-4°F/-20°C for 7 days, or -31°F/-35°C for 15 hours for blast freezing). If you’re planning to eat fish raw or lightly cured (like in sushi or ceviche), it’s absolutely crucial to use fish that has been specifically handled and frozen to destroy parasites, often labeled as “sushi-grade” or “sashimi-grade.” Though, even these terms aren’t strictly regulated everywhere, so again, know your supplier. It sounds a bit scary, but awareness and good practices mitigate these risks significantly. It’s about being informed, not fearful.

8. Proper Handling and Storage at Home: The Clock is Ticking

So you’ve successfully navigated the fish counter and brought home some beautiful fillets. Congratulations! But your job isn’t done yet. Proper storage at home is crucial to maintain that freshness until you’re ready to cook. Fish is highly perishable, and the clock is always ticking. As soon as you get home, get that fish into the refrigerator. Don’t leave it sitting on the counter while you unpack the rest of your groceries. The ideal temperature for storing fresh fish is as close to 32°F (0°C) as possible, which is usually colder than the main compartment of most home refrigerators. The best spot is typically the coldest part of your fridge, often the bottom shelf towards the back, or in a dedicated meat/fish drawer if it’s properly chilled. I sometimes place the packaged fish on a bed of ice in a container, similar to how it’s displayed at a good fish market. Just make sure the melted ice can drain away so the fish isn’t sitting in water.

If the fish came in butcher paper or a loose plastic bag, it’s a good idea to rewrap it or place it in an airtight container. This prevents fish odors from permeating other foods in your fridge and also protects the fish from drying out. Generally, fresh fish fillets should be cooked within one to two days of purchase. If you don’t plan to use them within that timeframe, freezing is your best option. To freeze fish, pat it dry, then wrap it tightly in plastic wrap, followed by a layer of aluminum foil or a freezer-safe bag, squeezing out as much air as possible. Label it with the date and type of fish. Properly frozen, lean fish can last for 6-8 months, while fattier fish like salmon or mackerel are best used within 2-3 months, as their fats can go rancid even when frozen. Remember, the goal is to minimize exposure to air and maintain a consistent, very cold temperature. It’s a bit like protecting a valuable asset – which, let’s face it, good quality fish is!

9. Red Flags During Preparation: When to Toss It, No Questions Asked

Even if a fish fillet passed your initial inspection at the store, always give it another once-over before you cook it. Sometimes, signs of spoilage can become more apparent after the fish has been home for a day, or as you begin to prepare it. If you unwrap the fish and are hit with a strong ammonia, sour, or overly “fishy” smell, that’s a major red flag. Don’t try to mask it with marinades or spices; your nose is telling you something important. The texture is another critical checkpoint. If the flesh feels excessively slimy, sticky, or mushy to the touch when you’re rinsing or patting it dry, that’s a bad sign. It should still feel firm and resilient. As you’re cutting or handling the fillets, look at the color and consistency again. Is there any unusual discoloration that you didn’t notice before? Is the flesh separating or falling apart too easily? These can be signs that the fish is past its prime. I once had a piece of halibut that looked fine in the package, but when I went to cut it, it practically disintegrated. Lesson learned – into the bin it went.

If you’re making something like ceviche where the fish is “cooked” in citrus juice, pay extra attention. The acid will firm up the fish, but it won’t kill all bacteria or neutralize toxins like histamine. So, the fish must be impeccably fresh to begin with. Any doubt here, and it’s an absolute no-go. Another thing to be wary of is any unusual iridescence or sheen that looks unnatural, or any signs of mold (though mold is less common on fish than other spoilage signs unless it’s been stored very poorly for a long time). The guiding principle here is simple: when in doubt, throw it out. It’s just not worth the risk of foodborne illness. A few dollars wasted on a bad fillet is far preferable to a miserable night (or worse). Trust your senses and your judgment. It’s that internal risk assessment we all do. For fish, the stakes are just a bit higher, so err on the side of caution.

10. Trust Your Gut (Literally and Figuratively): When in Doubt, Throw it Out

This final point really encapsulates everything we’ve discussed. After all the looking, smelling, and touching, if there’s still a nagging doubt in your mind about a piece of fish, listen to that instinct. Your intuition is a powerful tool, often honed by subtle cues your conscious mind might not fully register. Maybe the fishmonger seemed a bit evasive, or the lighting in the supermarket display was a little too flattering, or there’s just something indescribable that feels ‘off’ about the fillet. Don’t dismiss these feelings. I’ve learned over the years that trying to convince myself that a questionable piece of fish is “probably fine” usually leads to regret, either in the form of a disappointing meal or, worse, an upset stomach. It’s just not worth it. That little voice of doubt? It’s often right. It’s your internal quality control system, refined by experience and, well, common sense.

This principle – “When in doubt, throw it out” – is a cornerstone of food safety, and it applies with particular force to highly perishable items like fish. The potential consequences of eating spoiled fish can range from mild discomfort to severe food poisoning. Why take the chance? Even if it means a last-minute change of dinner plans, it’s always better to be safe than sorry. Think of it as an investment in your well-being. Over time, as you become more experienced in selecting fish, your confidence will grow, and you’ll rely less on doubt and more on informed judgment. But even the most seasoned chefs will occasionally encounter a piece of fish that doesn’t meet their standards, and they wouldn’t hesitate to reject it. So, give yourself permission to be discerning, to be cautious. Your health, and the enjoyment of your meal, depends on it. It’s a simple rule, but perhaps the most important one of all when it comes to handling fish. And who knows, maybe Luna will give your perfectly chosen fillet her paw of approval too!

Final Thoughts on Your Fin-tastic Fish Future

Well, there you have it – a pretty comprehensive dive into the world of selecting fish fillets and avoiding those dreaded bad ones. It might seem like a lot to remember, but honestly, it boils down to engaging your senses, asking the right questions, and trusting your judgment. From understanding what ‘fresh’ truly implies beyond a simple date, to recognizing the subtle visual, olfactory, and textural cues, you’re now armed with the knowledge to make much better choices. Remember the importance of the source, the value of deciphering labels, and the fact that good quality frozen fish can be a fantastic ally in your kitchen. And, of course, proper handling once you get that precious fillet home is key to preserving its quality. It’s a journey, this culinary exploration, and every shopping trip is a chance to refine your skills. I still have moments where I pause and really scrutinize a piece of fish, even now.

My challenge to you? Next time you’re shopping for fish, slow down. Really look. Ask a question. Maybe even politely ask for a sniff if you’re at a proper fish counter. Don’t just grab the first fillet that looks passably white. Engage with the process. You’ll not only end up with better tasting, safer fish, but you’ll also develop a deeper appreciation for this amazing food source. And who knows, maybe you’ll even start to enjoy the ‘hunt’ for that perfect fillet as much as I do. It’s a small skill that pays big dividends in deliciousness and peace of mind. Will you always get it 100% right? Maybe not, perfection is elusive. But you’ll dramatically swing the odds in your favor. Happy fishing, or rather, happy fish buying!

FAQ: Your Fish Fillet Queries Answered

Q: How long can I keep fresh fish fillets in the fridge after buying them?
A: Generally, you should aim to cook fresh fish fillets within 1 to 2 days of purchasing them. Store them in the coldest part of your refrigerator, ideally below 40°F (4°C), and make sure they are well-wrapped or in an airtight container to maintain quality and prevent odors from spreading.

Q: Is it safe to eat fish that smells a little “fishy”?
A: Truly fresh fish should smell clean and briny, like the ocean, not offensively “fishy.” A strong, unpleasant fishy odor, or any hint of ammonia or sourness, is a sign of spoilage. When in doubt, it’s always best to err on the side of caution and discard fish that has an off-putting smell. Trust your nose!

Q: What’s the best way to thaw frozen fish fillets?
A: The safest and best way to thaw frozen fish fillets is slowly in the refrigerator. Place the frozen fish in its packaging (or in a sealed bag) on a plate to catch any drips and leave it in the fridge for about 24 hours, or until completely thawed. If you’re short on time, you can thaw fish in a sealed bag under cold running water, but avoid using warm water or thawing at room temperature, as this can encourage bacterial growth.

Q: Can I refreeze fish fillets that have been thawed?
A: It’s generally not recommended to refreeze fish fillets that have been fully thawed, especially if they were thawed at room temperature or in warm water. Thawing and refreezing can negatively affect the texture and quality of the fish, making it mushy and increasing moisture loss. If the fish was thawed safely in the refrigerator and hasn’t been out for long, refreezing might be technically safe but quality will suffer. It’s always best to cook thawed fish promptly.

@article{spotting-bad-fish-fillets-sammys-tips-for-freshness,
    title   = {Spotting Bad Fish Fillets: Sammy’s Tips for Freshness},
    author  = {Chef's icon},
    year    = {2025},
    journal = {Chef's Icon},
    url     = {https://chefsicon.com/how-to-avoid-bad-fish-fillets/}
}