Debone Any Fish: Keep the Blade Flat on the Spine

To debone a fish, use a thin, flexible fillet knife 6 to 9 inches long. Keep the flat of the blade pressed lightly against the spine as you cut from head to tail, then pull the pin bones with needle-nose pliers at a slight angle toward the head. Chill the fish and pat it dry first so it doesn't slide under the knife.

Most people go wrong partway down the first side. The knife starts sawing, the fillet comes away in shreds, and a third of the flesh stays on the bones. That's rarely a hands problem.

Keep the blade flat on the bone.

Why fillets come out ragged

A chef's knife is too thick and too stiff to follow a fish skeleton, so it tears the flesh instead of sliding along it. A dull fillet knife does the same thing. If your cuts leave ragged edges, check the edge before you blame your technique.

The other culprit is pressure. A sharp fillet knife should move with almost no downward force. If you're pressing hard, you're fighting the fish, and the blade drifts off the bone into the meat. Cooks who skip the cut along the spine and go straight at the rib section get the same result: uneven fillets with chunks left on the carcass.

On the line, whole fish comes in and gets broken down at the station before service. The cooks who do it fast aren't doing anything exotic. They use a flexible blade and a cold fish, and they cut along the spine before anything else. That's worth copying at home, because a whole fish costs less per pound than skinless boneless fillets and holds its moisture and flavor longer than fish that was cut a day or two ago.

Related: The 3 Sharpening Angles That Fix a Dull Knife Fast

How to fillet a round fish

Salmon, trout, sea bass and snapper share the same layout. The spine runs down the center, the ribs angle out from it, and one fillet sits on each side.

1. Chill and dry the fish. Keep it cold right up until you cut, since cold flesh is firmer and holds together under the knife. Pat every surface dry with paper towels, and set a damp towel under the board so it can't slide.
2. Cut behind the head. Lay the fish on its side and make a diagonal cut just behind the pectoral fin, down until you feel the spine. Don't cut through it.
3. Turn the blade flat. Rotate the knife so the blade is horizontal and pointing toward the tail. Keep the flat pressed lightly against the spine and slice toward the tail in long, smooth strokes. Don't saw back and forth.
4. Work the ribs last. Near the belly the rib bones curve inward. Feel them with a fingertip, angle the blade slightly and slice underneath them, staying close to the bone and using the tip of the knife rather than the heel. Rushing here is where you lose flesh.
5. Lift and repeat. At the tail the fillet should come away cleanly. Flip the fish and do the other side.
6. Skin it if the recipe calls for skinless. Lay the fillet skin side down and grip the tail end of the skin. Hold the knife at a low, almost flat angle and slide it between skin and flesh with short forward strokes while you pull the skin back with your other hand.

How do I get the pin bones out?

Pin bones are the thin bones that run in a line through the thickest part of most fillets, especially salmon and trout. They sit just under the surface and angle slightly toward the head. Run two fingers firmly down the center of the fillet from head to tail and you'll feel the tips poking up.

Don't pull them straight up. That tears the muscle and often snaps the bone, leaving half of it behind. Grip each one with needle-nose pliers and pull at a slight angle toward the head, the way the bone already points. Hardware-store pliers work fine and fish tweezers are a small upgrade. Bare fingers won't hold a wet bone.

When you're done, run your hand over the flesh one more time and check the board for loose bones. If you're portioning the fillet afterward, cut across the grain of the muscle for cleaner edges and better texture once it's cooked.

What about flatfish and the carcass?

Sole and flounder are built differently. The spine runs down the center of the top side, and four fillets come off instead of two. Pin bones are less common, and the principle doesn't change: keep the blade nearly parallel to the bones, never perpendicular to them.

Don't throw out the frame. The bones, head and collar make a stock in about 20 minutes that goes into seafood sauces, risottos and chowders. Rinse the carcass under cold water, pull the gills if they're still attached, and simmer with aromatics. Lean white fish gives the cleanest stock. Salmon and mackerel frames turn it strong and oily, so I'd skip those for stock.

If this is your first whole fish, buy a trout or a small snapper rather than a big salmon. The anatomy is the same, and your early mistakes cost less.

Related: Why Restaurant Fish Tastes Better, and How to Sear It