SCALLOPS
SCALLOPS OFFER SEVERAL POSSIBLE CHOICES FOR the cook, both when shopping and cooking. There are three main varieties of scallops—sea, bay, and calico. Sea scallops are available year-round throughout the country and are the best choice in most instances. Like all scallops, the product sold at the market is the dense, disk-shaped muscle that propels the live scallop in its shell through the water. The guts and roe are usually jettisoned at sea because they are so perishable. Ivory-colored sea scallops are usually at least an inch in diameter (and often much bigger) and look like squat marshmallows. Sometimes they are sold cut-up, but we found that they can lose moisture when handled this way and are best purchased whole.
Small, cork-shaped bay scallops (about half an inch in diameter) are harvested in a small area from Cape Cod to Long Island. Bay scallops are seasonal—available from late fall through midwinter—and are very expensive, up to $20 a pound. They are delicious but nearly impossible to find outside of top restaurants.
Calico scallops are a small species (less than half an inch across and taller than they are wide) harvested in the southern United States and around the world. They are inexpensive (often priced at just a few dollars a pound) but generally not terribly good. Unlike sea and bay scallops, which are harvested by hand, calicos are shucked by machine steaming. This steaming partially cooks them and give them an opaque look. Calicos are often sold as "bays," but they are not the same thing. In our kitchen test, we found that calicos are easy to overcook and often end up with a rubbery, eraser-like texture. Our recommendation is to stick with sea scallops, unless you have access to real bay scallops.
In addition to choosing the right species, you should inquire about processing when purchasing scallops. Most scallops (by some estimates up to 90 percent of the retail supply) are dipped in a phosphate-and-water mixture that may also contain citric and sorbic acids. Processing extends shelf life but harms the flavor and texture of the scallop. Its naturally delicate, sweet flavor can be masked by the bitter-tasting chemicals. Even worse, scallops absorb water during processing, which is thrown off when they are cooked. You can't brown processed scallops in a skillet—they shed so much liquid that they steam.
By law, processed scallops must be identified at the wholesale level, so ask your fishmonger. Also, look at the scallops. Scallops are naturally ivory or pinkish tan; processing turns them bright white. Processed scallops are slippery and swollen and usually sitting in milky white liquid at the store. Unprocessed scallops (also called dry scallops) are sticky and flabby. If they are surrounded by any liquid (and often they are not), the juices are clear, not white.
Besides the obvious objections (why pay for water weight or processing that detracts from their natural flavor?), processed scallops are more difficult to cook. We found that sautéing to carmelize the exterior to a concentrated, nutty flavored, brown and tan crust is the best way to cook scallops. The caramelized exterior greatly enhances the natural sweetness of the scallop and provides a nice crisp contrast with the tender interior.
The most common problem a cook runs into with scallops is getting a nice crust before the scallop overcooks and toughens. We started our tests by focusing on the fat in the pan. Since scallops cook quickly, we knew it would be important to choose a fat that browns efficiently. We tried butter, olive oil, canola oil, a combination of butter and oil, plus cooking in oil with a finish of butter at the end for flavor.
To preserve the creamy texture of the flesh, we cooked the scallops to medium-rare, which means the scallop is hot all the way through but the center still retains some translucence. As a scallop cooks, the soft flesh firms and you can see an opaqueness that starts at the bottom of the scallop, where it sits in the pan, and slowly creeps up toward the center. The scallop is medium-rare when the sides have firmed up and all but about the middle third of the scallop has turned opaque.
The scallops browned well in all the fats we tested, but butter produced the thickest crust and best flavor. The nutty taste of butter complements the sweetness of the scallop without compromising its delicate flavor. We tested various pans, and while the technique worked in both nonstick and regular skillets, we recommend a light-colored regular skillet so you can judge how quickly the butter is browning and regulate the heat if necessary.
Despite the origin of the word sauté, which means "to jump" in French, it's critical for the formation of a good crust to leave the scallop alone once it hits the pan. We found the best method for cooking was to place the scallops carefully in the pan one at a time, with one flat side down for maximum contact with the hot pan. We turned the scallops once and browned the second flat side. The best tool for turning scallops is a pair of tongs, although a spatula can be used in a pinch.
We recommend pan-searing in butter as the best all-purpose method for cooking scallops. Like shrimp, scallops can also be breaded and deep-fried. While the preparation is simple (just remove the small muscle on each side of the scallop), frying the scallops presented more of a problem than we thought they would in our testing.
We tried simply breading and frying sea scallops, but differing sizes caused trouble. The big ones didn't cook through before they became too dark. We tried using calicos instead. They were a pain to dredge because they are so small, and they became tough when cooked. We went back to frying sea scallops, slicing them in half at the equator, and although this improved their cooking, they lost some appeal as flat discs. So we opted to leave the small ones (about 1 inch in diameter and 3/4 inch high) whole. If you can only buy larger scallops, cut them in half vertically, or in quarters if the scallops are really quite large (more than 11/2 inches in diameter).