Fish: Selection, Cleaning, and Cooking, Is It Fresh and How Does It Cook?
Telling fresh from stale at the counter, the right cleaning technique, cooking for oily and lean fish, from Türkiye's fish map to FDA parasite rules, a practical guide.
The Tatonia Editors··10 min read
Fish is the most delicate protein in the kitchen. If meat is mishandled for a day, you can barely tell; fish gives away the change within three hours. Overcooked meat is "overdone"; in the same condition, fish loses its texture entirely. This sensitivity is tied to its chemistry: less connective tissue, higher water content, and a fat profile that oxidises easily. Picking fish correctly and cooking it correctly comes down to a few fundamentals.
Spotting fresh fish: the four-sense test
At the market or the fishmonger, trusting the label alone is a mistake. With four senses you can read freshness in seconds.
1. Eye: a fresh fish's eye is bright, slightly bulging, and clear in the pupil. According to Tasting Table's and Serious Eats' fishmonger guides, a stale fish's eye is cloudy, sunken, and matt. In thawed previously-frozen fish the eye can be slightly cloudy but should still be rounded.
2. Gills: lift the gill cover and look inside. Vivid red or pink is a marker of freshness. Brown, grey, or sticky-yellow gills signal staleness. Supermarkets sometimes refuse this test; a fishmonger usually allows it.
3. Smell: a fresh fish smells lightly of sea and iodine, a tolerable note. Ammonia, sharpness, or a sweetish-bad note means the protein has started breaking down. "Fish always smells fishy" is wrong; truly fresh seafood does not give a strong smell.
4. Texture: press the body of the fish gently with a finger. A fresh fish springs back, with no indent. If a fingerprint remains, the protein has lost its structure. This test is especially critical for fillets.
These four sensory checks take seconds and catch 80 percent of the quality problems at the supermarket counter.
Fish varieties and seasons in Türkiye
Different fish peak in different seasons. Off-season fish is either frozen or farmed.
Hamsi (Black Sea): November to March. In season, it is Türkiye's cheapest high-quality protein. Small, oily, suitable for grilling, pan, or steaming. Hamsi pilavı is the classic.
Horse mackerel: October to March. Marmara and Mediterranean. Small, oily. Pan or grill.
Bonito: September to November. The autumn icon of the Black Sea and Marmara. Oven, grill, lakerda (salt-cured fermentation).
Bluefish (lüfer): September to March. The Marmara's luxury fish. Five names by size: defne yaprağı (small), çinekop (medium), sarıkanat (medium-large), lüfer (full), kofana (largest). This naming system is a particular detail of fishing culture.
Sea bream (dorado): year-round. Aegean and Mediterranean. White, sweet flesh. A grill classic. Both wild and farmed versions.
Sea bass: year-round. Aegean and Mediterranean. Leaner and softer than sea bream. Oven, salt-baking.
Whiting: November to April. Black Sea. Small, lean. Cooks easily, perfect for children.
Turbot: March to June. Black Sea. Flat fish, lean but fleshy. The classic fish for pan with butter.
Salmon (imported): year-round. Frozen from Norway or Chile. There is no native salmon in Türkiye, the available product is farmed. Oily, ideal for grill and oven.
Sardine: April to August. Marmara and Aegean. Small, oily fish, a grill icon.
At home cleaning can look daunting, but it takes 10 minutes with the right knife and discipline.
Tools: a sharp medium-sized fish knife (thin, flexible), a cutting board (preferably plastic; the fish smell sticks to plastic but it cleans easily), paper towel, a mixing bowl.
Step 1: Scaling. Hold the fish by the tail and scrape with the back of the knife from tail to head. A dedicated scaling tool works too. Place the fish in a bowl of water or scale underwater to keep scales from flying.
Step 2: Opening the belly. From the vent to the head, cut a straight line along the belly. Don't go deep, or you tear the intestine.
Step 3: Removing the innards. Pinch the organs between two fingers and pull towards the jaw. Gut, liver, kidneys come out as one mass. If a black peritoneal membrane runs along the spine, scrape it out too; that membrane turns bitter when cooked.
Step 4: Remove the gills (mandatory for grilling, optional for pan). Scrape with the knife under the gill plates. Gills spoil fastest during cooking.
Step 5: Rinsing. Rinse the inside and outside with cold running water. Too much rinsing washes the flavour out; 15 to 20 seconds is enough. Never soap or detergent.
Step 6: Drying. Dry the inside and outside thoroughly with paper towel. A wet fish does not sear, it boils. This is the most-skipped step that makes the biggest difference.
Filleting (for larger fish)
For medium-sized fish like sea bream, sea bass, and bonito, filleting before grilling is often practical.
Cut: behind the head, make a vertical cut down to the spine. Lay the knife along the spine and slide towards the tail. The first fillet comes off. Flip the fish and do the same on the other side. Two fillets plus the spine.
Pin bones. The fine bones inside the fillet usually run horizontally. Feel with a finger, pull with tweezers. Quality fishmongers do this at delivery, but most of the time it is done at home.
Skin. On sea bass and salmon, skin gives a crisp crust during cooking, so leave it on. For small hamsi and horse mackerel, the skin is eaten as part of the fish. For raw use (ceviche, tartare), skin is removed.
Oily vs lean fish: the cooking logic
The fat percentage of the fish drives the cooking method.
Oily fish (hamsi, sardine, bonito, salmon, mackerel, tuna): pink-red flesh, 5 to 15 percent fat. Cooks in its own fat. Grill, oven, steaming are ideal; in the pan, a little extra fat is enough. Quick searing over high heat leaves crisp edges and soft interior.
Lean white fish (whiting, sea bass, sea bream, turbot): white flesh, 1 to 3 percent fat. Can dry out during cooking, so added fat is essential. Pan-frying in butter or olive oil, oven with olive oil and lemon, or salt-baking (which preserves the fish's own moisture) are the right methods.
Larger meat fish (swordfish, tuna, large bluefish): cut into steaks (thick slices) and treated like a beefsteak. Internal temperature matters; the USDA minimum is 63°C. There are tuna methods that leave the centre raw, but only with sushi-grade fish from the right source.
Cooking methods
Grill: charcoal or cast-iron grill pan. Dry the fish, marinate with olive oil + salt + lemon (30 min), place on the grill. Skin side down, no movement (the grill must be very hot and the fish should not be lifted). 3 to 5 minutes per side, thick steaks 5 to 7 minutes.
Pan: a ridged grill pan is ideal, a regular pan also works. Low-medium heat plus a mix of butter and olive oil. For sea bream and sea bass, 3 to 4 minutes per side. Small fish like hamsi take 2 minutes per side.
Oven: 180 to 200°C. Place on a greased tray, top with olive oil + lemon + herbs, cover or leave open. 10 minutes per cm of thickness as a rule of thumb. A 2 cm fillet 20 minutes, a 4 cm steak 40 minutes.
Steaming: the fish sits over steam, no oil at all. Hamsi buğulaması is a Black Sea classic. Arrange the fish over a tomato-paste sauce, cover, 15 to 20 minutes.
Salt baking: a whole sea bass or sea bream is encased in coarse salt, baked at 200°C for 30 to 40 minutes. The salt forms a hard shell, the fish retains its own moisture, and the result is extremely tender. The salt crust is broken at the table.
A practical check: press with a fork or knife at the thickest part. If the fish is opaque and flakes easily, it is done. If more than half still looks translucent, continue.
Chef-level medium: bring the fish to 57 to 60°C and rest. The centre stays slightly glassy and moist. Salmon and tuna deepen at this level, though it sits below the USDA minimum from a safety standpoint.
Overcooked fish gives a white, dry, fibrous texture. The proteins have contracted tightly and lost all moisture. This happens fastest in lean white fish; 1 minute makes the difference.
Raw fish and parasites: the FDA rule
Sushi, sashimi, ceviche, tartare and other raw fish dishes need extra care. Anisakis simplex and Anisakis pegreffii parasites can be present. Salmon, herring, mackerel, tuna, and wild Pacific Alaska fish carry higher risk.
According to the FDA Food Code, fish to be served raw must meet one of the following freezing conditions:
-20°C for 7 days (168 hours), home freezer; or
-35°C for 15 hours of freezing, then held at the same temperature (professional); or
-35°C freeze, then held at -20°C for 24 hours
These conditions kill parasites with certainty. Heat treatment (63°C for a minimum of 15 seconds) achieves the same effect.
"Sushi grade" is not an official term. Neither the FDA nor the Turkish Food Codex recognises it. "Sushi grade" is marketing; the real assurance is checking the freezing history of the fish you buy. In Türkiye, quality sushi restaurants use imported frozen salmon or tuna.
A home freezer is usually around -18°C, slightly below the FDA standard. Technically 10 to 14 days are advised instead of 7, but because home temperature stability is not perfect, home sushi remains riskier. For cooked fish dishes a home freezer is fine.
Common mistakes
Over-rinsing. 15 seconds are enough. Holding a fish under running water for minutes washes flavour out and breaks the texture.
Not drying the surface. A wet fish on a hot pan steams and breaks the sear; instead of cooking it boils. Paper towel, always.
Cooking straight from the fridge. Cold fish in a pan drops the pan temperature; the cooking time stretches and the outside dries while the centre is undercooked. Rest at room temperature for 10 to 15 minutes.
Wrong-side-down start. Most fish go in skin-side first. The skin needs 3 to 4 minutes of contact to crisp; if started the other way, the skin stays soft.
Too much flipping. Fish is fragile; one flip is enough for searing. Constant flipping breaks it apart.
Squeezing lemon before cooking. Acid denatures the fish protein, leaving a "cooked" look without proper heat (the ceviche technique). Squeeze lemon at service.
Burning oil in a too-hot pan. If the oil overheats before the fish goes in, the fish sticks. Medium heat plus a little oil plus a dry fish equals a working sear.
A closing thought
Fish is the protein that demands the most discipline in the kitchen. Right choice, fast cleaning, right method, controlled time. As long as you do not break these four steps, hamsi, bonito, lüfer, and sea bass from Türkiye's seas can all make for an excellent dinner. Learning to cook fish brings a more delicate kitchen discipline than meat, and that discipline carries over positively to other cooking too.