Why Score a Whole Fish Before Baking?

The thickest part of a whole fish is its back, and heat reaches it last. The tail and belly may already be cooked while the back is still raw. Scoring helps reduce this difference: heat moves inward through the opening made by each cut, so the thick section cooks faster. The effect may seem small, but on a whole gilthead seabream or sea bass it can save a few minutes; that may be what determines whether the fish dries out. For the same reason, place the fish on the baking sheet with its thick side facing the back wall of the oven, where it is hotter.

The second purpose is seasoning. The fish's skin is a barrier that keeps salt and spices from penetrating; salt sprinkled only on the surface mostly stays there during cooking. Salt, lemon, and spices rubbed into the cuts reach the flesh directly. For the same reason, season the belly cavity separately, then add a lemon slice, a bay leaf, or fresh herbs. Together, these two steps solve the problem of a whole fish tasting bland.

The third purpose is to preserve the fish's shape. The skin shrinks during cooking, but the flesh does not shrink as much; this difference can curl the fish to one side and keep it from sitting flat on a baking sheet or grill. Cuts divide the skin and release this tension, helping the fish stay flat. The same idea applies to skin-on fillets: a few shallow cuts on the skin side help prevent curling and let the entire piece touch the grill grate or pan.

Make diagonal cuts on two sides of the fish with the tip of a knife. Depth matters: each cut should go through the skin and only the first 1–2 cm of flesh; it should not reach the bones. Deep cuts open during cooking, let the juices escape, and can cause the fish to break apart. Space the cuts about 1.5–2 cm apart; three or four cuts on each side are enough for a portion-size fish. Make more cuts on larger fish, but keep them just as shallow. Use a sharp knife; a dull knife pushes the skin instead of cutting it, so the cut does not open cleanly.

Not every fish needs to be scored. Small fish such as anchovies, sardines, and horse mackerel are already thin, so they do not need scoring; if scored, they fall apart. Fillets and slices do not need scoring either, although shallow cuts can be made on the skin side of a skin-on fillet. Scoring is mainly useful for large whole fish served in portions. Pat a scored fish thoroughly dry before cooking; otherwise, water that collects in the cuts prevents the surface from browning. Thin lemon slices placed in the cuts add flavor and keep the cuts from closing during cooking.