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Sea Scallops: How to Avoid Getting Soaked
Buying scallops, those delicious, sweet white morsels of shellfish muscle, used to be simple: you had your large "sea" scallops and your small "bay" scallops, and you could get them fresh or frozen. Now, in addition to these choices, scallop buyers need a whole new vocabulary, including "chemical free," "dry pack," and "day boat" scallops.
Scallops, in North American terminology, refers both to the bivalve shellfish with the distinctive eared shell (think of the Shell Oil logo) and to the part we eat, which is the large central adductor muscle that holds the two shell halves together. In a sea scallop, the adductor muscle can be as big as two inches in diameter, and weigh up to an ounce and a half. (I'll leave the smaller bay scallops, and the other small types that sell under the same name, for another column.)
The most common sea scallop in North American markets, and the one that sets the standard for flavor, is Placopecten magellanicus, a large variety found in relatively deep water from Newfoundland to North Carolina. Weather permitting, they are fished throughout the year, mostly by dredging the bottom with a large rake that gathers the shellfish into a chain net.
Unlike clams, oysters, and other bivalves, scallops cannot survive long out of the water, so they are usually shucked on the boat shortly after harvest and the meats are kept chilled until delivered to shoreside processors. Many of the East Coast scallop fishing grounds are far enough offshore that fishing trips commonly take several days. Wholesale buyers of fresh scallops have traditionally paid a premium for the freshest, "last of the catch" or "top of the catch" scallops. The same premium applies to those boats that make shorter fishing trips, ideally 24 hours or less, so the entire catch is the last day's catch. These days, the same menus that trumpet their dry-farmed tomatoes and line-caught tuna are likely to list not just scallops, but "day boat" scallops.
Atlantic sea scallops are shipped all over North America both frozen and fresh, but buyers on the West Coast may also encounter another large variety from Alaskan waters, the weathervane scallop (Patinopecten caurinus). Although these scallops are especially large, the overall catch is small, only a tiny fraction of the East Coast harvest. Because of the distance from the fishing grounds to distribution points and final markets, virtually all the Alaska scallop catch is frozen at sea. The ones I have tasted have been of excellent quality, though milder in flavor than Atlantic scallops.
The Alaska scallops also bear a newly popular label, "chemical free." For years, inexpensive frozen scallops (as well as many other frozen seafoods) have routinely been treated with phosphates, particularly sodium tripolyphosphate (STP), to reduce so-called "drip loss." STP and other related phosphates are GRAS (generally recognized as safe) food additives, and used in moderation, they help bind the natural moisture in seafood through the freezing and thawing process.
As useful as phosphates are with frozen seafood, they are subject to abuse when applied to fresh seafoods, especially scallops. If a little STP can keep the natural moisture in seafood, a lot can cause it to soak up additional water -- increasing in weight by up to 25 percent -- and since water is a lot cheaper than scallops, there is a powerful economic incentive to "soak" them. Reports of abuse of phosphates in fresh seafood processing led to a crackdown by the Food and Drug Administration in the early 1990s, and the establishment of an upper limit on the moisture content of scallops that can be sold as natural and unadulterated. If the amount of moisture exceeds 80 percent of the weight of the scallops, presumably the maximum natural water content, they fall into a separate product category which must be labeled "scallop product -- water added."
In practice, this standard does not prevent the use of STP on fresh scallops, but it prevents processors from using STP to increase the weight of scallops without labeling them as such. Even if added weight were not an issue, phosphates can affect the naturally sweet flavors of scallops. Chefs and discerning consumers, through their wholesale suppliers, increasingly insist on "dry pack," or unsoaked, scallops (although this is nothing new, according to New England scallop processors, as the fresh scallops sold in better markets and restaurants have always been untreated).
Now the phosphate question has come full circle, as an increasing number of buyers have decided that a "100 percent natural, chemical free" label is worth a little drip loss in the frozen product as well. Challenging conventional wisdom, buyers for a few retail chains and natural-foods stores began some years ago to demand phosphate-free frozen scallops, and from what I have tasted, the quality hasn't suffered a bit. The cooked scallops may "weep" a bit more moisture onto the plate than they would if treated, but the clean, sweet flavor and texture more than makes up for it.
Like shrimp and lobster tails, scallops are sorted and priced according to size. While retailers sometimes use terms like medium, large, and jumbo, buyers and sellers in the wholesale and restaurant trade usually specify sizes numerically, such as 10-20, 20-30, or 30-40. These numbers represent the number of pieces it takes to make up a pound; thus the smaller the number, the larger the individual scallop meats.
And like shrimp, the larger sizes of scallops command higher prices. Somewhere along the line, the curves for the pieces per pound and dollars per pound cross, and it's not unusual to pay more than a dollar apiece retail for the largest scallops. At such a price, you don't want the scallops getting lost in a generic "seafood" dish, or swamped in a sauce that masks their flavor. Taking the lead from restaurant chefs (who pay nearly as much), savvy cooks will want to give these valuable nuggets center stage, albeit with a strong supporting cast of vegetables or other ingredients to fill out the plate.
One of the best ways to treat large scallops is like little filets mignons -- seared in a hot skillet until the outside is browned and a little crusty, and the center is anywhere from rare to medium rare. In company with a substantial side dish, like the simple saffron-scented risotto studded with peas given here, three really big scallops or four slightly smaller ones make an adequate portion. This is one case where those standard 100-gram (3.5-ounce) servings used in nutritional analysis make sense.
If you can't find (or don't want to pay for) the really big ones, this dish will taste fine with any large sea scallops; you just won't have quite the same visual and textural impact.
When shopping for fresh or thawed scallops, look for ivory or creamy-colored meats, even as dark as a light tan; a stark, bleached white can be a sign of heavy phosphate treatment. There should be little or no milky liquid in the tray, another sign of heavy soaking. In fact, the best dry-packed scallops are often a bit sticky. A fairly strong sweet-briny aroma is also not a problem, but a fishy or sour smell indicates spoilage.
Seared Jumbo Scallops with Saffron Risotto
To avoid overwhelming the flavor of the scallops, use a delicately flavored stock. Homemade chicken stock thinned with an equal amount of water is ideal; otherwise use a thin fish stock. If only salted stock is available, dilute it well and eliminate the salt in the recipe.
3/4 pound jumbo sea scallops, fresh or thawed (12 to 16 pieces)
4 cups (approximately) unsalted stock
1/4 cup dry white wine or Champagne
Large pinch saffron threads
2 tablespoons olive oil
2 tablespoons finely chopped shallot or onion
1-1/3 cups Arborio rice
1/2 teaspoon salt
Freshly ground pepper to taste
1 cup petite peas, fresh or thawed
If there are any tough white strips along the short edge of the scallops, remove them and combine the trimmings with the stock and bring to a simmer. Combine the wine and saffron threads in a small bowl and let stand in a warm place. Set the scallops aside on a plate at room temperature.
Heat the oil in a medium-sized heavy saucepan and saute the shallots just until translucent. Stir in the rice and cook a minute or two, coating it thoroughly with the oil. Add the wine and saffron and enough stock to just cover the rice. Stir in 1/2 teaspoon salt and a pinch of pepper and cook uncovered, stirring frequently, until the liquid is nearly absorbed. Continue adding stock a ladleful at a time, cooking until it is absorbed before the next addition. When the grains begin to swell, taste a grain; it should have a trace of crunchiness in the center. At this point, set a large nonstick skillet on another burner to preheat and season the scallops with a little salt and pepper.
Add another ladleful of stock to the risotto, cook it down and taste again. When the center of the grain is al dente and the outside is beginning to melt away into a creamy mass, adjust the seasoning and stir in the peas. Meanwhile, turn the heat under the other skillet to high, coat the pan with a thin film of oil, and add the scallops in a single layer. Cook about 1 minute per side, or until nicely browned.
Spoon the risotto on warmed plates in a crescent or circle, leaving space in the center for the scallops. Serve immediately.
Jay Harlow is a Bay Area cookbook publisher and author of ten books including Once Upon a Bagel, The California Seafood cookbook & Beer Cuisine.