Dishes made from green crabs – stocks, stews, a pasta sauce that the chefs of Venice call mazanetta, and soft-shell green crabs deep-fried in batter – are unexpectedly delicious. This is partly due to the crabs' taste – "a very delicate sweetness," as Legal Seafood's executive chef, Rich Vellante puts it – and partly due to a long-lasting and heightened flavor characteristic that food enthusiasts call umami. Unlike the four main tastes (sweet, sour, salty, and bitter), umami is more of an effect, enriching the other tastes in a dish and leaving a long, complex, pleasing set of sensations in the mouth, "like notes that hang in the air in a cathedral after the music stops," as one of us wrote in the Boston Globe Magazine. 

 

Food science helps explain this. A USDA chemist discovered that green crabs are rich in two naturally-occuring proteins, glutamic acid and aspartic acid, which top the list of known umami-producing compounds. In a crude attempt to copy this effect, the Asian food industry sells a synthetic umami-producer, called monosodium glutamate, or MSG. With green crabs, you get an organic flavor booster that is far more complex and pleasing than anything food chemists have devised. Try it in a risotto or stew or chowder and see for yourself.