How To Cook & breakdown a frozen lobster

Here's the thing nobody tells you about cooking a frozen lobster: it's almost certainly already cooked. Every whole lobster we sell, and nearly every one you'll find frozen anywhere in Britain, went into the freezer straight from the pot. So the job isn't cooking. It's defrosting properly, warming gently if you want it warm, and then getting the meat out without wrecking it. Two minutes of Alistair doing all three:

Can you cook a lobster straight from frozen?

You can, and you'll regret it. A lobster is dense; heat it from frozen and the outside is done long before the middle has thawed, so you end up with tough claws around a cold tail. Defrost it first: overnight in the fridge on a plate, 12 to 24 hours depending on size. If you're stuck, a sealed bag in cold water gets a 450g lobster there in an hour or two. Never warm water, never the microwave. More on defrosting here.

How do you warm a cooked frozen lobster?

Once defrosted, it's ready to eat cold, which is how a lobster roll or a plat de fruits de mer wants it anyway. If you want it hot, split it lengthways, brush the cut side with melted butter, and give it 8 to 10 minutes in a 180°C oven or under a medium grill until the meat is warmed through. That's it. Every extra minute costs you texture. Ten minutes in boiling water, as some guides suggest, is for a raw lobster, and it will ruin a cooked one.

What if it really is raw?

Raw whole lobster is a rare thing in the frozen trade; raw tails less so. For a raw tail, split it, butter it and grill or bake at 200°C for 8 to 12 minutes depending on size, until the flesh has turned from translucent to white all the way through. For a raw whole lobster, salted water at a rolling boil, about 10 minutes for the first 450g and 3 more for each 450g after that.

How do you break down a whole lobster?

Twist the claws off at the body. Twist the tail off the same way, then either bend it flat and squeeze until the shell cracks, or cut down the underside with kitchen scissors and lift the meat out in one piece. Pull out the dark thread running along the top of the tail meat. Crack the claws with the back of a heavy knife or nutcrackers; the knuckle joints hold a surprising amount of meat, which is what the lobster pick is for. Here's the claw job on its own:

How much meat do you get?

About a third of the weight in a clawed lobster, so a 450g lobster gives you roughly 150g of meat: a generous main for one, or a starter for two. If that arithmetic disappoints you, a rock lobster tail is nearly all meat, and our picked lobster meat skips the shell altogether.

What parts of a lobster can't you eat?

The shell, obviously. The feathery gills in the head, the small sac behind the eyes (the stomach), and the dark thread along the tail. The green tomalley in the body and any red roe are edible and prized by some; some official advice is to go easy on the tomalley, so treat it as a taste rather than a course.

Which lobster should you buy?

Our Cooked Whole Wild Lobster is the North American one, 350 to 450g, cooked and frozen whole, and the sensible choice for thermidor or surf and turf. The Wild Cooked British Lobster is the native, sweeter and dearer, from Scotland or Cornwall depending on the season. Both arrive frozen; defrosted the way we describe above, we'd defy you to tell them from a lobster cooked that morning, and if you can, we'll give you your money back. The whole range is here.