All natural produce that is consumed relates in some way to a season. Crabs’ seasonality is dictated by when they breed, but more importantly it’s their growth phases that decree when they are best consumed.
Crabs begin life as tiny round eggs held to their mother’s abdomen before becoming fertilised and released as zoea, small floating larvae. As they grow they go through a process called moulting. Each time a crab is big enough to have filled its shell, beneath which it will have cleverly started growing a whole new exoskeleton, it will draw in water, crack the old shell and squeeze itself out. This is when crabs are at their most vulnerable and will hide as they wait for their protective shell to harden. When they’re caught at this stage, regardless of breed, they are eaten or sold as soft shells, cooked whole and particularly delicious deep-fried.
The process of moulting happens fairly regularly in the initial stages of a crab’s life, but as they mature the cycle slows to about every 28 to 30 days, hence the myth of using the lunar cycle to judge when crabs should be caught for eating. The best time to eat a crab is just before the moult happens, although this is obviously difficult to detect when you are in the fish shop, so your best bet it to choose crabs that feel the heaviest. Another good trick is to look at its underside – if it looks rusty or a little dirty, it means it’s older and full; clean and white indicates a sparkly new home that it’s still yet to grow into.
Claw and order
Crabs are crustaceans, creatures with a hard exoskeleton made of calcium carbonate, that have been around since the Jurassic period. They can live on land and water, salty or fresh, as long as they have enough moisture to keep their gills – also known as ‘dead man’s fingers’ – damp. They have two front pincers or claws, three middle legs and two back legs for swimming. Their front claws are used for holding and carrying food, communicating, digging, fighting or aggressively waving about.
Generally it’s the male crabs that are sold, although the flesh of the female is said to be sweeter and has the added bonus of delicious roe that is considered a delicacy. The easiest way to tell the difference is by looking at the abdomen and the flap that holds the head to the body – the female’s is dome-shaped and looks a little like a pagoda, whereas the male’s is narrower and more triangular. There is sometimes also a colour difference between them, and females usually have smaller claws. Most female crabs get thrown back; it’s illegal to sell them in Queensland, which actually helps maintain their sustainable abundance in Australia. That, and the fact a female can release up to five million eggs per cycle.
A cast of crabs
Scuttle into a fish market in Australia looking for crabs and your choice will be between the three types that we commercially fish: blue swimmer, mud or spanner. The blue swimmer is an excellent crab, its name coming from its distinctive colouring. It has mildly sweet flesh, a soft body, high meat-to-shell ratio, and is less expensive than other species, making them very easy to work with. They are usually sold after they have been killed – bright orange when cooked and referred to as ‘green’ when raw. Mud crabs – a beautiful mottled grey blue in colour – are nearly always sold while still alive, as once dead they release toxins that can make you quite sick. The flesh is firmer and has a stronger, sweeter flavour that can be overly rich. Spanner crabs have a more elongated body and their front claws are tool-shaped. They can be sold both live and dead, and usually it’s their meat you’ll find if you buy pre-picked crab flesh.
If you are lucky, you may stumble across other varieties as a result of bycatch. I have the privilege of an excellent seafood supplier and have been able to cook with some uncommon crabs. The spider crab, though prolific, is not generally sold. It is large and has an extremely hard exoskeleton – I tackled its shell to make a delicious rich crab broth with tomato and hints of chilli. I’ve cooked with two-spot and three-spot crabs, both small and annoying to get the meat out of but oh-so delicate and delicious, and I once used the extremely sweet and tiny coral crabs in a dessert. There’s a plethora of varieties – tiny crabs that make their home in oyster shells, and Japanese spider crabs that can span up to four meters. There’s also the very large king crab types that are not actually a crab, but are treated the same way. And then there are the lurid crab sticks, originating in Japan, but they’re not really crab either.
Worth the effort
I understand why crabs can be a little daunting. Apart from their scary claws and beady eyes, they can be a lot of messy effort for what seems only a little reward. This can be especially so when you are faced with a live crab and, despite years of practice, actually having to kill one still makes me uneasy. The easiest method, I believe, is to place them in the freezer for about 45 minutes and then drop them in boiling water or swiftly chop them down the middle with a cleaver. You can also spike them between the eyes or insert a chopstick from the bottom straight through the body.
And then you are faced with extracting the meat. Although time-consuming on a large scale, it is actually fairly simple to do once you’ve had a little practice and is equally as easy with a raw or cooked crab. You first remove the top shell, making sure to keep the tasty juices, and discard the gills, before removing the legs and claws and cutting the body in half. Then it’s just a matter of methodically working your way through all the sections – scissors help, as does a crab picker. Always pick through the mean again at the end to prevent any stray bits of shell getting in your way. If you are working with a raw crab, you have the added benefit of the shells to use. You can make a delicious oil, bright orange and the very essence of shellfish flavour; or a tasty stock – add some ginger and chilli and it can become the base of an excellent aromatic Asian soup.
The other easy, and also very delicious, way to cook the crab is whole, perhaps the famous Singapore chilli crab, or in a tasty Sri Lankan curry. Although there is nothing like the simplicity of a whole crab boiled or roasted with a delicious sauce to dip into. If all of that seems too hard, though, you can always just cheat and buy picked crabmeat.
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Photography by Sharyn Cairns. Styling by Lee Blaylock. Food preparation by Rachael Lane.
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