How To

Deshell Crab

, Soft Shell Crab Vs Hard Shell Crab, Cleaning And Cooking The Crustacean

Quick Summary

How to deshell crab or crabs can be tricky if you are not used to handling seafood, especially when two kinds exist when it comes to this crustacean. It gets easier once you know which crab you are holding. One kind is the hard-shell crab, which has a firm, fully formed shell and the most meat, so it needs cleaning, cooking and cracking. A soft-shell crab is one that has just moulted. In India, that means either a low-meat ‘water crab’ or a farmed crab eaten whole. This guide covers how to tell them apart, how to choose the best crab in an Indian fish market, how to clean crab safely, and how to get the meat out with and without a crab cutter. 

Deep Dive

Low in fat and a good source of protein, crabs are worth cooking every once in a while, given that India has over 100 species of them along the coasts, mangroves, backwaters, rivers and estuaries. This is one source where the human body can get its omega-3 fatty acids from, which are vital for brain functioning, heart health and cells. The best part about consuming crab meat is that you need to buy them fresh, as crab meat tends to deteriorate rapidly once it dies. Head to your local fishmonger or seafood specialist who might have live crabs moving around in a vessel filled with water. You can ask them to process them for you or bring the crabs home and clean, cook and deshell the crustaceans yourself. 

Soft Shell Crab Vs Hard Shell Crab

Crabs grow by shedding their shells. Before a moult, the crab drinks large amounts of water, which cracks the old shell open. The newly emerged crab is extremely soft and takes a few days to absorb calcium and harden its new shell. Until that happens, there is little meat inside. A recently moulted crab whose shell still flexes will yield little meat when cooked.

In Indian markets, this gives you two kinds of soft crab. The first is the water crab, a freshly moulted mud crab sold cheaply. Farmers buy them and rear them for 20 to 40 days until the shell hardens. Hardened crabs, locally called ‘mud’ (meat) crabs, fetch three to four times the price of soft ones. The second is the farmed soft-shell crab, harvested at the moment of moulting so the whole body can be eaten. A commercial unit in Purba Medinipur, West Bengal, produces soft-shelled orange-clawed mud crab, a species grown largely for export markets.

Which Crabs Are Sold In India?

Over 640 crab species have been recorded in Indian waters, but only eight are commonly called edible crabs. Three portunid crabs make up most regular landings: the blue swimming crab, the three-spot crab (Portunus sanguinolentus) and Charybdis feriatus. Tamil Nadu leads in blue swimming crab landings. Mud crabs (Scylla) are the big brackish-water crabs. In the wild, Scylla serrata can reach about 2.5 kg, while Scylla olivacea typically reaches 600 to 700 g.

How To Pick The Best Crab At The Market

• Buy live. Choose a lively crab that feels heavy for its size, and skip uncooked dead crabs, since you cannot tell how long they have been dead.

• Test its reflexes. Fresh crabs raise their claws when a hand approaches.

• Smell it. It should smell of the sea. Avoid any crab with an ammonia odour.

• Press the shell. A hard-shelled crab should not flex. Flex means a recent moult and little meat.

• Check the limbs. Choose crabs that feel heavy with legs and claws intact. A crab that loses limbs also loses market value.

• Watch the price. A much lower price for the same size can signal a water crab.

How To Clean Crab At Home

Start by calming the crab. Chilling it in the freezer for 30 to 40 minutes puts it to sleep. Do not freeze it, and cook it promptly, because bacteria work on the meat once the crab is dead.

1. Rinse the crab under cold running water and scrub the shell.

2. Flip it onto its back and lift the apron, the triangular flap on the belly. It is narrow and pointed on males, wider and rounded on females. Pull it off.

3. Pry off the top shell, or carapace, from the gap at the back. Keep it for stock.

4. Remove the spongy gills, the mouth and the innards. Rinse the body.

5. Cut the body into quarters by splitting it down the middle, then halving each side. Twist off the claws and legs.

Cleaning crab also raises the question of the yellow-green "crab butter". Some home cooks add it to gravies. The New York State Department of Health advises discarding blue crab tomalley because contaminants concentrate there, and California health authorities found elevated domoic acid in Dungeness crab tomalley. The meat itself is typically unaffected. California advises against using the water from cooking whole crabs in sauces or stocks. These are overseas advisories, but they are worth knowing before you add it to a gravy.

Cleaning Soft Shell Crab

Most of the body is eaten, so the job is lighter.

1. Rinse gently under cold running water and pat dry.

2. With kitchen shears, cut off about half an inch at the front, including the eye sockets and mouth. Cut through the fluid-filled sac behind the face to stop them popping as they cook.

3. Lift the pointed ends of the top shell on each side and remove the gills.

4. Turn the crab over, lift the apron and snip it off.

The intestines are left in and cook through, so removing them is optional. Soft shell crabs are very perishable, so use them immediately.

How To Cook Crab After Cleaning

For whole hard shell crabs, boil them in well-salted water. The timing is 8 minutes per 500 g up to 1 kg, counted from when the water returns to the boil, followed by a dip in iced water. Boiling dilutes some of the crab's juices, so steaming is the alternative. Cleaned, quartered crab can also go straight into a masala, as in classic nandu and kekda curries. For soft shell crab, dredge in seasoned flour or cornmeal, shake off the excess and pan-fry over heat high enough to make them sizzle. Use a splatter screen, as they spit.

How To Deshell Crab With A Crab Cutter

A crab cutter, or cracker, works best on cooked, cooled hard-shell crab.

1. Remove the large claws and the three middle legs by pinching at the base and twisting.

2. Lay each claw flat and crack it along its length. Squeeze just enough to split the shell without crushing the meat.

3. Crack the thick leg segments the same way.

4. Peel back the apron, lift off the top shell and remove the gills. Break the body in half and pick out the meat with a fork or pick.

Go easy on slender legs. On softer or smaller legs, crackers tend to bust the meat into a mess.

How To Deshell Crab Without A Crab Cutter

You can use typical kitchen tools to do the job, like knives or scissors, without investing in professional seafood equipment or cutters. 

• Knife and mallet: Set the edge of a butter knife where you want the crack and tap it with a mallet. The back of a chef's knife, a meat tenderiser or a sturdy rolling pin also cracks claw shells. A pestle works too. Tap once or twice, just enough to crack the shell.

• Scissors: Cut leg shells lengthwise to keep the meat intact. You can also snip about half an inch off both ends of a leg segment, hold it upright and rap it against your palm so the meat slides out in one piece.

• Small legs: Snap them in half and pull the meat out.

• Body: Halve or quarter it, then use the tip of a knife or a small spoon to pick out the meat. There is very little meat where the legs join the body.

Crab Handling Made Easy

The nutrients in crabs are what might make you want to consider browsing a soft-shell crab vs a hard-shell crab and decide which one you might want to try. There are so many Indian crab recipes like the Bengali kakrar jhal, Tamil nandu kuzhambu, Goan xec xec, Mangalorean crab sukka and more. You can try them all or stick to the comforting flavours of your home and indulge in this delicious crustacean.