Fish is at once the most challenging and rewarding of all foods. The challenge is posed by the care with which it must be cooked. Different types of fish can be adapted happily to almost every imaginable cooking method, and a large number of creative techniques are involved in their preparation. Here lies the prize, in the vast array of fish dishes, simple and sophisticated, classic and contemporary.
In recent years, the increasing efficiency of refrigerated transport has revolutionized the availability of fresh fish and created a true world market in seafood. A superb Atlantic salmon on the slab in Hawaii may have been caught in Norway only 72 hours earlier. As consumers, we benefit not only from refrigerated air transport but also from major advances in processing technology on harvesting vessels. Although freezing does affect the texture of fish, in many cases it does less damage than would occur naturally through bacterial growth. If well-handled fish is frozen immediately, at its peak of quality and at the right temperature, then correctly stored and delivered to the point of sale, deterioration should be slight. Commercial canning is a successful alternative, especially for oily fish such as salmon, tuna, anchovy and sardine.
The other revolution in the industry is fish farming. World demand for fish cannot be met by harvesting at sea alone, particularly as in some ocean areas, stocks of wild fish are being depleted or are under threat from pollution. Trout farming is now taken for granted and a more recent innovation is the harvesting of most Atlantic salmon under controlled conditions. In the United States, catfish farming has been an enormous success—in just over a decade, the annual yield has increased thirty-fold to 300 million pounds. As consumers, the concession we have to make for more plentiful supplies of farmed fish is greater standardization. The flavor and texture of wild fish can vary enormously; the quality of farmed fish is much more consistent, but rarely attains the excellence of the finest wild specimens.
Most important for the cook is an understanding of the differences in taste, texture and bone structure among the various kinds of fish. A fish with an oily, rich flesh, such as mackerel or herring, is as different from a white-fleshed fish, such as hake, as duck is from chicken. Texture is another important characteristic: the coarse flesh of the cod differs from the fine texture of sole and neither could be confused with the firmness of shark or the softness of whiting. Tuna, swordfish and other very big fish invariably appear in the market as steaks, many looking more like meat than fish. Fish with a cartilaginous structure and no transverse bones, such as shark, require different methods of preparation from fish like shad, which seem to be all bone if they are carelessly dissected. Flatfish such as turbot and sole and fish with compressed bodies, such as bream, are better suited to filleting than cutting into steaks. Small fish such as herring and trout are often left on the bone to cook whole, while larger ones like salmon may be sold whole, filleted or cut in steaks.
In this chapter, fish are grouped into 14 categories according to their cooking affinities. First come sole, flounder and other small flatfish offering a wide choice of quality and price. Even more highly prized are halibut and other larger flatfish. Ray and skate are given separate coverage (as are monkfish, and shark and sturgeon), because of their unique cartilaginous structure. The next group of firm-fleshed fish, which includes tuna and swordfish, have firm, meaty flesh.
Firm white fish from the Atlantic and Pacific (snapper and grouper among others) follow; then come flaky white fish, including saltwater bass and mullet. Next is the cod family, which includes hake and pollack among others. Thin-bodied fish like bream and jack are another category for the cook, as are gurnard and other fish that have large heads and are very bony.

Salmon and trout are considered together, followed by the wide range of other freshwater fish. Last come two groups of oily fish: the first includes herring and mackerel (as well as small fish usually deep-fried) and the second includes long-bodied fish like eel. The chapter also covers specific preparations such as caviar and other fish roes, raw fish dishes such as sushi, and fish preserved by drying, salting and smoking are also discussed.

One last word about identifying fish. Not only do fish come in every conceivable shape and size, from one-ounce minnows to one- or two-ton tuna, but also the common vocabulary used to describe different kinds of fish is also loose to the extent that the same fish can have a variety of names. For example, one species of flatfish is called American plaice, Canadian plaice, sand-dab or long rough dab, depending on where it is sold. The reverse is true of redfish, popular in the Cajun cuisine of the southern United States. As the cuisine grew more popular, many inferior species of fish were listed as “redfish” by retailers. Similarly in Britain some inferior flatfish are marked as “sole”, for example lemon sole or Torbay sole.