Why some shrimp are saltier than others.
When fresh shrimp are frozen (often just minutes after being caught), they are washed in a saline solution to help bring their temperature down faster. Quicker chilling prevents ice crystals from forming inside the shrimp, resulting in better texture when defrosted; it also helps keep them from clumping together as they freeze. "Easy-peel" shrimp are soaked in an additional sodium solution. Pro: They slip out of their shells effortlessly. Con: More salt. How much more?
THE TEST: We steamed and peeled five varieties of shrimp, then shipped them to the lab for sodium analysis.
THE RESULTS: (per 4 ounces steamed):
Wild-caught fresh Gulf shrimp (never frozen): 97mg;
Farm-raised fresh shrimp (previously frozen): 159mg;
Winn-Dixie individually quick-frozen easy-to-peel wild-caught shrimp: 245mg;
Whole Foods individually quick-frozen easy-to-peel shrimp: 483mg;
Publix fresh frozen easy-to-peel farm-raised shrimp: 730mg