Should You Buy a Whole Fish or Fillets?

The main advantage of a whole fish is that it has visible signs you can check. Lift the gill cover: the gills inside should look bright, vivid red, not brown or pale pink. The eyes should be clear and convex, not sunken or cloudy. When you press the flesh with a finger, it should spring back without leaving an indentation. It should smell of the sea; do not buy it if it has a sharp, ammonia-like odor. A fillet does not have any of these signs.

When buying a fillet, look for different, fewer signs. The cut surface should look bright and moist, not dull and dry; avoid a fillet with yellowed or browned edges. Any liquid collected on the flesh should be clear, not milky or cloudy. The flesh should also spring back when pressed with a finger. Check whether the fillet is displayed on ice in a separate compartment; do not buy one that has come into contact with liquid from other fish. Check for pin bones by gently moving a fingertip across the flesh, perpendicular to the direction of the fibers.

Account for yield when comparing prices. After the head, bones, skin, and organs are removed from a whole sea bream or sea bass, the edible meat left is roughly half the fish; the proportion varies by species. A whole fish that looks cheaper per kilogram may therefore cost close to a fillet when calculated by the edible meat that reaches the plate. However, do not discard the head and bones; they can be used for fish stock, which offsets the difference again.

The dish also affects the choice. Grilling, roasting a whole fish, and salt-baking call for a whole fish; the skin and bones hold the flesh together and slow drying. Steaming, pan-frying, and cooking in parchment are easier with fillets. Fillets are a clear convenience for meals with children or whenever diners do not want to deal with bones. For fish soup and dishes that need fish stock, a whole fish is essential because the bones and head provide the main flavor. Do not mix the two types in the same recipe—whole fish and fillets—because their cooking times do not match, even in the same oven.

There is a third option, and it is often the best: buy the whole fish and have it cleaned at the fish counter. This lets you check freshness at the time of purchase and leaves the work to the fish seller. Ask for the bones and head to be placed in a separate bag. Keep the cleaned fish cold on the way home; ask for an ice-packed bag or an insulated cooler. Do not let the fish sit at home: cook it the same day or portion it and freeze it.