To legions of devoted fans, soft shell crabs are just about the most bliss-inducing food on the planet. During the season (which begins in early Spring), soft shell fanatics eat them pan-fried, broiled, grilled, and deep-fried.
But for those who've never had the pleasure—and for those who have but want to know more about one of their favorite foods—here are some interesting facts, helpful tips, and tasty cooking ideas for soft shell crabs.
What They Are and How to Purchase Them
Contrary to popular belief, soft shell crabs aren't a separate species; they are just regular, hard shell crabs (most often blue crabs in the US) at a particular stage of growth.
For a crab to become larger, it must first discard its old shell and form a new one, which it does periodically throughout its life. To do this, it forms a new 'coat' under its old shell, then swells itself up enough to cause the top and bottom halves of the shell to separate, starting at the back.
The crab inside—in its new, soft 'coat'—is flexible enough to back out of the old shell. When it does, it looks very much like a regular hard shell crab, complete with serrated claws and swimmer fins—but it's about as hard as a rubber chicken!
In the wild, the crab is very weak and vulnerable after molting, and its shell begins to harden almost immediately. Within hours, it's back to being a hardshell crab.
So how do fishermen catch them in that brief interim period? Generally speaking, they don't. What they do is catch them just before they begin the process, then hold them in large, temperature-controlled tanks until they molt. The soft crabs are then removed from the water (which stops the hardening process) and packed in damp straw, seaweed, or other material before being shipped fresh to market or a processor for freezing.
When purchasing fresh soft shell crabs, buy them live if at all possible from a reputable seafood market. Live softshells will move very little and very slowly. Their shells will be very pliable. Don't hesitate to examine them closely; their claws are harmless in the soft-shell stage. Avoid any crab—live or dead—that has a strong smell of any sort; a fresh crab, like a fresh fish, smells of little more than the water it came from.
How to Prepare Soft Shell Crabs for Cooking
If you buy frozen soft shell crabs, they are almost certainly 'dressed' (cleaned) and ready to cook. If they are fresh, however, you'll need to prep them first. It's a simple process that begins with snipping straight across the front part of the shell just behind the eyes. This is most easily done with a pair of scissors, and it dispatches the crab instantly.
Next, lift each half of the top shell and remove the feathery gills, or 'lungs.' Then, flip the crab over and pull off the lower hinged plate (the part with the point) at the bottom of the shell. That's it—you're done!
How to Eat Soft Shell Crabs
Soft shell crabs are eaten whole, 'shell' and all. The shell is quite pliable, and the meat inside is incredibly sweet, juicy, and bursting with pure crab flavor.
Simple methods of cooking are often best: broiling, grilling, and especially, frying. As a rule of thumb, soft shells should be broiled or fried for about 4 minutes per side, or 8 minutes total; about 5 minutes per side on the grill.
Lightly flouring the crabs and pan-frying them in butter mixed with a little oil is popular. A variation on this is to cook them in butter and olive oil, then deglaze the pan with a splash of white wine, a squeeze of fresh lemon juice, a teaspoon or two of tiny capers, and some chopped fresh parsley, plus salt and cracked pepper to taste—an amazing and nearly instantaneous sauce.
Breaded and deep-fried soft shell crabs are a real treat. The classic sandwich is made with lettuce and tomato on a lightly toasted roll, spread with mayonnaise or just a hint of tartar sauce—nothing that might overwhelm the crab sweetness. Add a side of good coleslaw, and you're set.
You can use a standard coating or breader, or you can mix up your own by using half flour and half cornmeal, seasoned with a little garlic powder, a generous amount of black pepper, and a pinch of cayenne. You can even stuff them with a mushroom duxelle and bread them with Parmesan-laced crumbs if you want to be fancy.
A Word of Caution: When deep frying soft shells, steam can build up in the claws and legs, causing them to burst (and possibly spatter hot oil.) Avoid this by pushing a pin through each claw and leg segment before frying, or by placing a second fry basket inside the first to keep the crabs fully submerged in the oil.