Signs of High-Quality Fresh Fish and Shellfish

 

Signs of High-Quality Fresh Fish and Shellfish

Introduction

The first time I bought bad fish, I didn’t realise it until I was halfway through cooking. The texture was off — soft in a way that fish shouldn’t be — and the smell coming off the pan was sharp enough to make me genuinely reconsider the whole meal. I’d looked at it in the store and thought it seemed fine. I was wrong.

What I didn’t know then, and what took me an embarrassingly long time to figure out, is that reading a fish for freshness is actually a learnable skill. It’s not complicated. It doesn’t require any special tools or insider knowledge. It’s mostly just knowing what to look for — and once you do, you stop second-guessing yourself at the counter.

This guide covers the real signs of quality fresh fish and shellfish. Not a textbook version — just the practical stuff that actually helps when you’re standing there trying to decide whether something is worth buying.

Start With the Smell. Always the Smell.

Before you look at anything, smell it. If you’re at a counter where you can get close enough, do. If you’re at a self-serve case, pay attention the moment you open a package.

Fresh fish smells like the ocean. Clean, slightly salty, a little mineral — the kind of smell that feels natural, not offensive. It shouldn’t make you want to step back. It shouldn’t make you think “oh, that’s fishy.” That specific smell — the heavy, sour, ammonia-tinged odour that most people associate with bad seafood — is a byproduct of bacterial activity. It means the fish is past where you want it to be.

This one indicator alone will save you from most bad purchases. If it smells wrong, move on. Trust that instinct — it’s not being fussy, it’s being correct.

The same principle applies to shellfish, though it smells slightly different. Fresh shellfish has a clean, briny scent. Anything that smells sour, sulphurous, or genuinely unpleasant is a sign to leave it where it is.

Reading a Whole Fish

If you’re buying a whole fish — which, by the way, is one of the better ways to shop for seafood because it gives you so much more to assess — here’s what you’re looking at:

The eyes. Clear, bright, and slightly bulging. That’s what you want. Eyes that have gone cloudy, sunken, or dull are telling you the fish is old. It’s not a subtle signal — fresh fish have almost jewel-like eyes. Once you’ve seen it, you’ll notice immediately when something doesn’t measure up.

The gills. Lift them slightly if you can, or ask someone to. Fresh gills are a deep red or vivid pink. Anything browning, grey, or dried out means the fish has been sitting for a while. Gills are where the blood stays, so they’re one of the most sensitive freshness indicators on the fish.

The skin. Should look moist, slightly slick, and shiny. If the skin looks dull, is starting to dry at the edges, or has that slightly matte quality that aged fish gets — that’s age showing.

The smell again, but closer. Near the gills is where the smell of a whole fish is strongest. Fresh fish even smells clean right at the source. Any off-smell from the gills is a firm no.

Reading Fillets

Most people buy fillets more often than whole fish, and they’re a bit harder to read because you’re working with less. But there are still clear things to look for.

The flesh should look firm, dense, and somewhat translucent — not opaque or milky. A fillet that looks like it’s starting to go pale and dull is one that’s been sitting for a while. Colour should be consistent throughout, no discolouration at the edges, no browning.

Look at where the layers of flesh meet. Fresh fillets hold together. When fish start to age, those layers begin to gap and separate — you can see it visually as the fillet starts to look like it’s coming apart without being touched. That gaping texture is a sign of protein breakdown and not something you want to bring home.

Press it if you can. Fresh fish flesh is firm and springs back when you press it lightly. A dent that stays, or flesh that feels soft and slack — that’s old fish.

Shellfish: Slightly Different Rules

Shellfish — oysters, clams, mussels, scallops, shrimp — have their own freshness indicators, and they differ from finfish in some important ways.

Live shellfish (oysters, clams, mussels) should be alive. That sounds obvious, but it’s worth checking. Shells should be closed or should close when tapped. An open shell that doesn’t respond to being tapped is a dead shellfish, and a dead shellfish that’s been sitting around is not something you want to eat.

They should smell clean and oceanic. Any sour or ammonia smell coming from live shellfish is a bad sign.

Scallops are worth paying attention to because they’re sometimes treated with water-retaining solutions to plump them up. Fresh, untreated scallops — often called “dry scallops” — are slightly ivory or cream-coloured, sometimes with a natural tinge of orange or pink. If scallops look bright white and are sitting in milky liquid, they’ve likely been treated. They’ll also shrink dramatically when cooked. Dry scallops hold their size and sear properly.

Shrimp should feel firm and snap back when flexed slightly. Soft, slack, or mushy shrimp have started to break down. The shells should be intact, and the flesh should smell clean. Any sliminess or sharp smell — don’t bother.

At the Counter: What the Environment Tells You

The quality of the fish you’re buying is partly about the fish itself and partly about where it’s being sold. Both matter.

When you walk into a fish market or up to a seafood counter, look at how things are displayed. Fish should be sitting on clean, fresh ice — not a thin layer of old, slightly melted ice from three days ago. Cases should look clean and well-maintained. Fish should be arranged neatly, not stacked on top of each other in ways that damage the flesh.

The staff matter too. A counter where the person selling fish can answer basic questions — when it came in, where it’s from, what’s best today — is one that takes quality seriously. That knowledge doesn’t come from nowhere. It means someone is paying attention to what they’re stocking and how it’s being kept.

A good sign, maybe the simplest one: the place smells clean. Not “no smell at all” — a proper seafood counter will always have some oceanic scent. But it shouldn’t smell unpleasant. That clean, briny air is actually one of the fastest signals that the product moving through a place is genuinely fresh.

Conclusion

None of these checks takes long. Once you’ve done them a few times, they become automatic — you walk up to a counter, and your nose and eyes are already working before you’ve consciously started assessing anything.

The most important thing is just to trust what you’re picking up. Your instincts about smell and appearance are more reliable than you might think. If something looks dull and smells off, it probably is. If something looks bright and smells like the sea, you’re in good shape.

For more on finding the right place to buy seafood in the first place — suppliers, what to look for in a vendor, how to ask the right questions — have a read through our guide on Finding Quality Seafood in Your Area: A Practical Guide for Freshness, Selection, and Value. It pairs well with what’s here and gives you the sourcing side of the equation to go alongside knowing how to read what’s actually in front of you.

Good fish is out there. You just have to know what you’re looking at.