How do I cook a lobster at home?

A lobster is one meal where nearly all the cost is in the raw material, so the cooking has to be right first time. There is not much to it — the difficulty is in the timing window and in doing the dispatch properly rather than squeamishly. Buying it ready-cooked from a good fishmonger is a legitimate answer if you would rather not.

Safety

What you'll need

• A live lobster, claws banded
• A very large pan, or a hot grill
• Salt — around 30g per litre
• A heavy chef's knife
• A probe thermometer (optional)
• Kitchen scissors and a lobster pick (optional)

Step by step

1. Buy it lively and heavy.A good lobster is active, curls its tail up hard when lifted, and feels heavy for its size. A limp lobster with a hanging tail has been out of the water too long. Around 500 to 700g suits one person; a kilo feeds two.
2. Keep it cold and alive until you cook it.In the fridge, in an open box, covered with damp newspaper or a damp cloth. Never in fresh water and never sealed. Cook it the day you buy it.
3. Sedate it in the freezer.Thirty to forty-five minutes in the freezer, not longer. It should be completely unresponsive when you take it out. This is the step that matters most and it is the one people skip.
4. Dispatch it decisively.Lay it on a board, find the cross mark on the head behind the eyes, and drive the point of a heavy knife straight down through it, then bring the blade forward through the head. One firm movement. If you are boiling rather than splitting, this step still comes first.
5. Choose boiling or splitting and grilling.Boiling is more even and easier to time. Splitting and grilling gives better flavour and lets you get butter into the flesh, but a grill's heat is uneven and you need to watch it. Steaming is a good middle path and waterlogs the meat less than boiling.
6. If boiling, use heavily salted water and a rolling boil.About 30g of salt per litre. Lower it in head first, bring back to a boil and time from there: roughly ten minutes for the first 500g, then three to four minutes for each further 500g. The shell turns bright red long before the flesh is cooked, so do not use colour as a test.
7. If grilling, split it and cook shell-side down first.Split lengthways, remove the dark intestinal vein down the tail and the small grit sac in the head, brush the cut face with butter, and grill shell-side down for six to eight minutes before finishing flesh-side up for two or three.
8. Test the tail rather than guessing.The thickest part of the tail wants around 60°C. Without a thermometer, the flesh should be opaque white all through with no glassiness where it meets the shell, and it should come away from the shell easily.
9. Rest it briefly and serve.Five minutes. Then crack the claws, split the tail, and serve with melted butter and lemon. The green tomalley in the head and any red coral are edible and prized by some, though tomalley is where contaminants concentrate and is best eaten sparingly.

Tips

• Overcooking is far more damaging than slight undercooking. A lobster two minutes over is noticeably rubbery, and you cannot undo it.
• Cooked and cooled lobster is easier to pick than hot lobster and no worse for it. If you are making a salad or a roll, cook it in advance.
• The shells are the best seafood stock there is. Roast them, then simmer for thirty minutes for the base of a bisque.
• Frozen raw lobster tails are a much cheaper way to eat lobster and skip the dispatch entirely. They are not as good as a whole fresh lobster but they are far from a poor relation.
• If the idea of dispatching one is genuinely off-putting, a fishmonger will cook it for you the morning you want it. That is a sensible choice, not a cop-out.

Common mistakes

• Dropping a live, unchilled lobster into boiling water — It is a slow death for a sentient animal and it produces a worse result — the tail muscle contracts violently and the meat toughens. Chill first, always.
• Timing by shell colour — The pigment change happens within a minute or two of hitting the heat, long before the meat is cooked. Colour tells you the lobster has been heated, nothing more.
• Freezing it to death rather than sedating it — The freezer step is to make the animal insensible, not to kill it. Leaving it in for hours is neither humane nor good for the meat. Thirty to forty-five minutes, then dispatch.

Questions people ask