How to Clean an Octopus and Why Is It Pounded?

Turn the head inside out like a glove, then use your hand to scrape out and remove the organs. Turn the head right side out again. At the exact center where the arms join the body is a hard, beak-like structure; press upward from below with a finger to push it out, then pull it off and discard it. Cut around each eye in a circle with a knife to remove it. Rinse the octopus thoroughly under plenty of cold water, rubbing to clean between the suckers, where sand and sediment collect. You can separate the head and arms at this stage if you like, but leave them together if you plan to boil the octopus whole.

Octopus muscle consists of long fibers with a dense network of connective tissue between them. This network helps the octopus move flexibly in water, but in the kitchen it makes the meat resistant. Without pretreatment, it can remain tough even after a long cooking time. Pounding mechanically breaks down this connective tissue and helps the cooking liquid penetrate. Traditionally, the octopus is struck against a rock or pounded with a mallet to loosen the fibers.

Pounding has its own rules. Place the octopus on a flat, sturdy surface and use the flat side of a mallet or a rolling pin to strike evenly along the arms. The strokes should be firm but not forceful, and steady. Strike the thick sections more and the tips less; the process takes a few minutes. Overdoing it mashes the meat and causes it to fall apart during cooking. Today, freezing does much of this work, and the pounding step is skipped entirely in many kitchens.

Dip the cleaned octopus into boiling water several times, arms first; the arms curl, improving its appearance for serving. Then lower it completely into the pot and reduce the heat. The water should not be kept at a full boil; let it simmer gently. A vigorous boil can peel the skin and break apart the meat. Add salt at the end. Check for doneness with a fork: if it slides into the thickest part without resistance, the octopus is ready. Add only water to the pot; onion and bay leaf are enough, and this simplicity lets the octopus’s own flavor stand out.

If you leave the boiled octopus to cool in its own cooking liquid, it stays juicier; an octopus removed right away will shrink. Once cool, you can put the arms on a grill or in a pan to brown the outside in a few minutes, or serve them cold in a salad. Do not discard the cooking liquid; strain it and use it in rice or soup. Cooked octopus keeps for a few days in a covered container in the refrigerator and should not be left at room temperature for more than 2 hours. If you do not want the skin, rub it off easily with your fingers while the octopus is still warm after boiling.