Décorticage is the art of extracting meat from crustacean shells with maximum yield and minimum damage — a foundational skill for the poissonnier that determines the elegance of every lobster, crab, and langoustine presentation. LOBSTER: twist the tail from the body (a firm 180° twist snaps the joint cleanly). Crack claws with the back of a heavy knife, not a crusher (crushers create shell fragments). Extract claw meat in a single piece by cracking the knuckle joint and pulling — the entire claw muscle should emerge intact, still shaped like the claw. For the tail, insert scissors along the underside of the shell membrane, cut along both sides, and lift the membrane away — the tail meat slides out as a whole cylinder. Remove the intestinal vein (a dark thread running along the dorsal surface). CRAB: remove the apron (tail flap) on the underside, then twist off all legs and claws. Push the body up and out of the shell from the tail end. Remove and discard the dead man's fingers (feathery grey gills — these are toxic). The brown meat (tomalley) in the shell is scraped out and sieved. Claw and leg meat is extracted by cracking at each joint. LANGOUSTINE: twist the head off, then pinch the sides of the tail shell to crack it, and push the meat out from the tail end — it should emerge in one piece. A skilled poissonnier can extract 24 langoustine tails in under 3 minutes. Yield targets: lobster should yield 35-40% of live weight as meat; brown crab 25-30%; langoustine 30-35%. Below these figures, technique needs refinement.
Crack, don't crush — crushing creates shell fragments that are impossible to remove and dangerous to eat Extract claw meat in single pieces — broken claw meat lacks visual impact and dries out faster Remove all intestinal veins and gills — these are bitter, gritty, or mildly toxic Work quickly — extracted crustacean meat dries rapidly once exposed to air Yield matters: lobster 35-40%, crab 25-30%, langoustine 30-35% of live weight
Chill cooked crustaceans for 10 minutes before shelling — cold shells crack more cleanly and the meat firms slightly, making extraction easier For lobster, insert a chopstick into the tail from the end and push — the meat slides out in a single, perfect cylinder Save every scrap of shell, coral, and tomalley — these make shellfish butter and bisque that are more valuable per gram than the meat itself
Crushing shells with a nutcracker, generating sharp shell fragments throughout the meat Breaking lobster claws into multiple pieces rather than extracting the muscle whole Leaving the intestinal vein in lobster tails — it is visible and tastes of grit Discarding the brown meat from crab — it is intensely flavoured and essential for bisques, soups, and dressed crab Overhandling the meat after extraction — crustacean flesh bruises easily and turns mushy
Escoffier, Le Guide Culinaire; Larousse Gastronomique