NOTE: This is part one of a two-part series. See Part 2: How to Prepare Soft Shell Crabs for Cooking & How to Eat Them
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 & 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 actually 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 to 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.