How long do you cook a live mud crab?

Boil mud crab for 8 minutes for the first 500g, then add 5 minutes for each additional 500g. A typical 1kg mud crab takes about 13 minutes; a 1.5kg crab takes about 18 minutes. Steaming takes slightly longer — roughly 12 minutes for the first 500g plus 6 minutes per additional 500g. The crab is cooked when the shell turns a deep orange-red and the largest leg joint reaches 70°C internally.

How do you humanely kill a mud crab before cooking?

The RSPCA-recommended method is to chill the live crab in the freezer for 30–45 minutes (or in an ice slurry for 20 minutes) until it is completely unresponsive and insensible, then spike it through both nerve centres before cooking. Chilling alone does not kill the crab — it sedates it so the spiking is humane. Never drop a fully conscious crab into boiling water; it is both inhumane and causes the crab to shed legs.

Should you cook mud crab in salt water?

Yes. Cook mud crab in well-salted water — about 35g of salt per litre, which approximates seawater. This seasons the meat from the outside in and stops the natural sweetness leaching out into plain water. Some Gold Coast cooks use clean seawater directly. Sugar is not needed; the salt level is what matters.

How can you tell when a mud crab is fully cooked?

Three signs: (1) the shell turns deep orange-red all over, (2) a leg pulls away cleanly and the meat inside is opaque white, not translucent, and (3) the internal temperature at the thickest part of the body reaches 70°C. Undercooked crab meat looks glassy and sticks to the shell.

Is it better to boil or steam mud crab?

Steaming gives slightly sweeter, more concentrated meat because none of the flavour leaches into the water, and the meat is less likely to become waterlogged. Boiling is faster, cooks more evenly for very large crabs, and is easier if you don't have a large steamer. For crabs over 1.2kg, boiling is more reliable; for smaller crabs, steaming is excellent.

Can you cook a dead mud crab?

Only if it has been kept properly chilled and died very recently — within an hour or two — and shows no off smell. Mud crab deteriorates extremely fast once dead because digestive enzymes break down the meat. A crab that died in storage hours earlier, smells of ammonia, or has gone limp and discoloured should be discarded. This is why mud crab is sold live: buy it live and cook it the same day.

How much mud crab do you need per person?

Allow one 600–800g mud crab per person as a main course, or one 1–1.2kg crab to share between two as part of a larger seafood spread. Mud crab yields roughly 30–35% edible meat by weight, so a 1kg crab gives about 300–350g of meat.

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How to Cook Live Mud Crab: The Complete Gold Coast Guide

Tasman Star Team3 June 20267 min read

mud crablive crabhow to cook crabQueensland mud crabGold Coast seafood

How to Cook Live Mud Crab: The Complete Gold Coast Guide

How to Cook a Live Mud Crab: The Complete Gold Coast Guide

Quick answer — Sedate the live crab in the freezer for 30–45 minutes until unresponsive, spike it through both nerve centres, then boil in well-salted water (35g salt per litre): 8 minutes for the first 500g plus 5 minutes per extra 500g. A 1kg crab takes ~13 minutes. It's done when the shell is deep orange-red and the meat is opaque white. Plunge into iced water, then serve.

Key facts:

Sedate the crab first: 30–45 min in the freezer, or 20 min in an ice slurry, until unresponsive
Boiling time: 8 minutes for the first 500g + 5 minutes per additional 500g
A 1kg mud crab takes about 13 minutes to boil; a 1.5kg crab about 18 minutes
Cook in salted water (~35g salt per litre) or clean seawater for the sweetest meat
Done when the shell is deep orange-red and internal temperature reaches 70°C
Mud crab yields ~30–35% edible meat; allow one 600–800g crab per person
Always buy mud crab live and cook it the same day — it deteriorates fast once dead

Why Mud Crab Is Worth Doing Properly

Queensland mud crab (Scylla serrata) is one of the best eating crabs in the world — dense, sweet, faintly nutty meat in claws thick enough to need a cracker. On the Gold Coast it's a celebration food: chilli crab, crab in XO sauce, or simply cracked with lemon and good bread.

But it's also a live product, and that brings two responsibilities: cooking it humanely, and cooking it on the day so the meat is perfect. Get those two right and the rest is easy.

This guide covers the humane dispatch method, exact cooking times by weight, boiling vs steaming, and how to know when it's done.

Before You Cook: Buying and Holding a Live Mud Crab

A good live mud crab is heavy for its size, actively moving, and tightly closed. A light crab has recently moulted and the shell is half-empty. Press the shell — it should be hard, not papery.

Keep the crab alive and calm until you cook it:

Store in the fridge crisper (around 4–8°C) covered with a damp hessian sack or wet newspaper
Keep the claws banded
Do not submerge in fresh water or sit it in a sealed bag — both will kill it
Cook the same day you buy it for the best meat

For the full holding method, see our guide on how to keep live crabs alive before cooking.

Tasman Star sells live Queensland mud crab at both Gold Coast stores — graded by size, hard-shelled and full. Browse live seafood or call Varsity Lakes on (07) 5522 1221 to check the day's stock.

Step 1: Sedate the Crab (the Humane First Step)

This is the step most home cooks skip, and it's the most important one. Dropping a fully conscious crab into boiling water is both inhumane and produces worse food — the crab thrashes and sheds its legs, losing meat.

The RSPCA-recommended approach is to render the crab insensible by chilling, then dispatch it physically:

Method	Time	Notes
Freezer	30–45 minutes	Easiest at home; check it's fully unresponsive before proceeding
Ice slurry (ice + water)	~20 minutes	Faster; fully submerge the crab

The crab is ready when it does not respond at all when you touch its eyes or legs. Chilling sedates — it does not reliably kill. That's why the next step matters.

Step 2: Dispatch the Crab

Once the crab is unresponsive, dispatch it by spiking through both nerve centres. A mud crab has two:

Front centre — under the triangular flap at the head/mouth end
Rear centre — under the pointed tail flap folded against the underside

Flip the crab onto its back, lift each flap, and drive a sturdy, pointed knife or a dedicated crab spike straight down into each spot, moving the blade to destroy the ganglion. Done correctly the legs relax immediately.

This is the method recommended for two-nerve-centre crustaceans like mud crab and is quicker and more reliable than relying on boiling alone.

Step 3: Boiling Mud Crab (Times by Weight)

Boiling is the most reliable method, especially for larger crabs.

Bring a large pot of well-salted water to a rolling boil — about 35g of salt per litre (a heaped tablespoon), or use clean seawater. You want enough water to fully submerge the crab.
Lower the dispatched crab in. The water will drop off the boil — bring it back up and start timing from when it returns to the boil.
Cook by weight:

Crab weight	Boiling time
500g	8 minutes
750g	~10–11 minutes
1kg	~13 minutes
1.5kg	~18 minutes
2kg	~23 minutes

The formula: 8 minutes for the first 500g, then +5 minutes for every additional 500g. Don't overcook — past the mark the meat turns stringy and dry.

Step 4: Steaming Mud Crab (Sweeter Meat)

Steaming keeps every bit of flavour in the meat instead of leaching it into the water, so the result is noticeably sweeter and less watery.

Set up a steamer with a few centimetres of salted water below the basket; bring to a vigorous boil.
Place the dispatched crab in the basket, cover, and steam.
Times run a little longer than boiling:

Crab weight	Steaming time
500g	12 minutes
1kg	~18 minutes
1.5kg	~24 minutes

The formula: 12 minutes for the first 500g, then +6 minutes per additional 500g.

For crabs over 1.2kg, boiling cooks more evenly all the way to the centre; for smaller crabs, steaming is the connoisseur's choice.

How to Tell When Mud Crab Is Cooked

Three reliable signs:

Colour — the whole shell turns a deep, even orange-red. A patchy brownish-orange means it needs more time.
Meat — pull a leg away; the meat inside should be opaque white, not glassy or translucent, and should not cling stubbornly to the shell.
Temperature — a probe at the thickest part of the body reads 70°C.

Step 5: Cool, Crack, and Serve

Plunge the cooked crab into iced water for 2–3 minutes. This stops residual cooking and firms the meat so it releases cleanly from the shell.

To serve:

Twist off the claws and legs; crack the claws with the back of a heavy knife or a crab cracker
Lift off the top shell (carapace); remove and discard the feathery grey gills ("dead man's fingers") and the stomach sac behind the eyes
Cut the body in half to expose the body meat

For step-by-step cleaning and meat-picking, see how to clean and prepare crab.

Serve simply with lemon wedges, crusty bread, and a bowl for shells — or build it into a chilli crab or a garlic-butter bake.

How Much Mud Crab Per Person?

Serving style	Amount per person
Main course (crab the hero)	One 600–800g crab
Shared, as part of a seafood spread	One 1–1.2kg crab between two
Asian banquet (chilli/XO crab, multiple dishes)	400–500g crab per person

Mud crab yields about 30–35% edible meat, so a 1kg crab gives roughly 300–350g of picked meat.

Buying Live Mud Crab on the Gold Coast

Tasman Star Seafood stocks live Queensland mud crab graded by size at both stores:

Varsity Lakes — 20 Casua Dr, (07) 5522 1221
Labrador — 5–7 Olsen Ave, (07) 5529 2500

Because mud crab must be bought live, call ahead to confirm size and availability, especially for large crabs or multiple crabs for an event. Home delivery runs Monday, Tuesday, and Friday across the Gold Coast.

→ Not sure which crab to buy? Read mud crab vs sand crab vs spanner crab to choose the right one for your dish.

Browse live seafood at Tasman Star →

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Order live mud crabs online from Tasman Star Seafood — Gold Coast delivery, open 7 days.

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