You can buy shrimp either raw or cooked. Most of the shrimp sold in the United States is flash-frozen on the fishing boat. It may be sold frozen or the market may thaw it before displaying it at the fish counter. Occasionally you may find shrimp that has not been previously frozen.
Shrimp is sold by the pound and described by the "count," which means the approximate number of individual shrimp in a pound. The higher the count, the smaller the shrimp. The smallest can be significantly less expensive and although the texture and flavor remain the same, peeling them takes longer.
Canned "salad" shrimp has been cooked and peeled. Often very small shrimp are used. The texture is softer than that of fresh or frozen shrimp.
Two pounds raw shrimp will yield about 1 pound peeled, cooked shrimp.
SHOPPING FOR QUALITY
Uncooked shrimp should smell of the sea with no hint of ammonia and have a firm-looking flesh. The shells will be translucent and may look grayish, possibly tinged with green or pink.
Cooked shrimp (shelled or unshelled) should look pink.
Packages of frozen shrimp should be tightly sealed, solid, and free from ice crystals.
PREPARATION
Shrimp may be peeled before cooking, especially if they will be served hot. Peeling after cooking is easier and suitable if shrimp will be served cold.