Start with the eyes
Whole fish give you the most information, and the eyes are the first thing to check. They should be clear, bright and slightly bulging. As the hours pass, the eyes cloud over and sink back into the head. A grey, sunken eye tells you the fish has been sitting around — factor that into your plans.
The gills come next. Lift them gently and look for a deep, clean red — the colour of fresh blood. Gills that have turned brown or pink-grey, or smell strongly ammoniated, indicate age. A fishmonger who knows their trade won't mind you checking; if anything, they'll respect you for it.
Skin, scales and flesh
On a fresh whole fish, the skin is glossy and the scales lie flat and tight, with an iridescent sheen that suggests the sea. Dullness and looseness are both warning signs.
Press the flesh with a fingertip — it should spring back immediately. If an indent lingers, the cellular structure has begun to break down. It is one of the most reliable tests available, and the one most people skip. On a fillet, look for flesh that is moist and slightly translucent rather than opaque and dry at the edges. Gaping — where the natural flakes have begun to separate — is the fillet's equivalent of sunken eyes. It doesn't mean the fish is inedible, but it isn't at its best.
Trust your nose
Fresh fish smells of the sea: clean, faintly briny, perhaps a little mineral. The sharp, sour smell that puts many people off fish altogether is the smell of fish that has been out of the water too long. A good fishmonger's counter should smell oceanic, not offensive.
For fillets, avoid anything that looks wet in the wrong way. A milky liquid pooling beneath the fish in its tray is a sign of age. Moist is good; weeping is not.
Why buying whole makes sense
Buy whole and ask your fishmonger to fillet it for you. You get to assess eyes, gills and skin before a single cut is made, then take home a fillet whose condition you verified yourself. Most fishmongers will do this as a matter of course — it costs nothing extra and gives you considerably more confidence in what you're taking home.
While you're at the counter, ask what came in that day. A good fishmonger will answer without hesitation and may steer you away from something that arrived earlier in the week. That kind of conversation is one of the main reasons to use an independent fishmonger: the knowledge is there if you ask for it.
Getting it home and storing it well
The journey from counter to fridge matters more than most people realise. If you have other shopping to do afterwards, ask for the fish to be well wrapped and keep it in the coolest part of your bag. At home, store it in the coldest part of the fridge — usually the bottom shelf, away from the door — and plan to cook it the same day or the next.
If you're buying ahead, most fish freezes well provided it goes in fresh. Wrap it well to prevent freezer burn and defrost slowly in the fridge rather than at room temperature.
Knowing what's in season
What you buy is closely tied to what's in season — species at their peak for flavour, condition and sustainability shift throughout the year. Our fish seasons articles cover this in detail and are worth reading alongside the practical advice here: knowing which fish is at its best right now makes the choosing considerably easier.
