Buying fish starts with the condition of the product, not with the species name. Even expensive fish becomes mediocre if it has been stored too long, thawed badly, or kept sitting in water.
Whole fish
Fresh whole fish has clear eyes, not cloudy or sunken ones. The skin is moist and shiny without a sticky film, and the scales hold firmly. Gills should be red or pink, with no brown coating or heavy odor.
Press the side of the fish: the flesh should feel firm and spring back. Smell is the fastest test. Good fish smells like the sea, cucumber, clean water, or almost nothing; sharp sour, ammonia, or stale fish odor means walk away.
Fillets and steaks
Fillets are harder to judge because eyes and gills are gone. Look at the cut surface: it should be even and moist, not wet. Sticky surface, gray patches, loose texture, and liquid pooling in the package all point to poor storage.
Fatty fish may have a stronger aroma, but it should not smell rancid. If a fillet is sold as chilled, ask whether it was previously frozen: that is normal for many species, but repeated thawing matters.
Frozen fish
Good frozen fish is often safer than random chilled fish. The package should be intact, with no snow coat, thick ice, or crystals inside. Those signs usually mean the fish thawed and froze again.
For tartare, ceviche, and other raw fish dishes, freshness is not enough; safe deep-freezing matters. A home freezer may not provide the required conditions, so buy raw-serving fish from a seller who understands parasite control and temperature.
Transport and storage
Buy fish near the end of your shopping trip and carry it in an insulated bag or next to cold products. At home, place it immediately on the coldest refrigerator shelf and cook it the same day or the next.
If you need to freeze fish, do it right away, not after two days in the refrigerator. Thaw slowly in the refrigerator so less liquid leaves the flesh and the texture stays firmer.
