How to Break Down a Whole Fish

The Benefits of the Whole Fish

Walking past the fishmonger counter, it is tempting to point at the pristine, pre-cut, plastic-wrapped fillets. However, buying a whole, intact fish offers massive advantages to the home cook.

First, it is significantly cheaper per pound. Second, a whole fish cannot hide its age; you can inspect the eyes (they should be clear and bulging) and the gills (they should be bright red) to guarantee absolute freshness. Finally, filleting the fish yourself leaves you with the head and spine, which makes a phenomenal, rich fish stock that you would otherwise have to pay for.

The Essential Tools

Do not attempt this with a dull, thick chef's knife.

You need a flexible filleting or boning knife. The blade must be able to bend and contour against the spine of the fish to maximize your meat yield.
You need a sturdy pair of kitchen shears for removing the fins.
You need a pair of fish bone tweezers (or clean needle-nose pliers) to remove the pin bones.
A clean, dedicated plastic cutting board (wood will absorb the fish oils and smell permanently).

Step-by-Step Filleting Process

This guide assumes the fish has already been scaled and gutted by the fishmonger (which they will do for free upon request). We will use a standard round fish (like a snapper, bass, or trout) for this method.

Step 1: Prep the fish. Rinse the fish under cold water and pat it absolutely bone dry with paper towels. A slippery fish is extremely dangerous. Use shears to snip off all the sharp fins along the top (dorsal) and bottom (anal) of the fish.
Step 2: The Head Cut. Lay the fish flat on the board with the spine facing you. Lift the pectoral fin (the side fin near the gills). Place your knife just behind the gills, angle the blade slightly toward the head, and cut firmly down until you hit the spine. Do not cut completely through the spine.
Step 3: Score the back. Turn the fish so the back is facing up. Make a shallow, guiding incision along the entire length of the spine, from the head cut all the way to the tail.
Step 4: Ride the bones. Insert the tip of your flexible knife into the guiding incision near the head. With the blade angled slightly downward against the spine, make long, sweeping strokes toward the tail. You should feel (and hear) the knife clicking against the rib bones.
Step 5: Release the fillet. As you slice deeper, use your non-dominant hand to gently pull the flesh away from the bones. Once you reach the spine, angle the knife over it and cut down through the ribcage to completely free the first fillet.
Step 6: The Second Fillet. Flip the fish over and repeat the exact same process on the other side. You are now left with two fillets and a central skeleton (save the skeleton for stock).
Step 7: Remove the rib cage. Lay the fillet skin-side down. Slide the knife carefully under the thin rib bones attached to the belly flap, angling the blade up slightly to avoid losing meat, and slice them away.
Step 8: Remove the pin bones. Run your finger down the center line of the fillet. You will feel a row of tiny, sharp bones. Use your tweezers to grip them firmly and pull them out in the direction they are pointing (usually toward the head).

Skinning the Fillet (Optional)

If you want skinless fillets, leave the pin bones in until after skinning.

Place the fillet skin-side down with the tail end facing you.
Make a small incision down to the skin at the tail. Grip the tiny flap of skin firmly with a paper towel.
Angle your knife down toward the board. Wiggle the skin aggressively back and forth while keeping the knife stationary, letting the skin pull itself off the blade.

Filleting a fish requires practice, but the reward is pristine, perfectly portioned fish at a fraction of the cost, along with the immense satisfaction of mastering a professional butcher skill.