BUYING FISH

How much fish to buy...
According to Canada's Food Guide, the size of a serving is usually considered to be 60 to 90 g (2 to 3 oz) of cooked boneless fish. The actual size of a serving, however, as we eat in Canada, is more likely to be 180 to 225 g (6 to 8 oz). The amount of fish to buy per serving for a recipe depends on the size of the servings and on the form in which the fish is purchased.
The following table shows approximately the number of servings to expect from the various cuts of fresh and frozen fish available.

How to judge quality when buying fish...
In order to prepare a fish dish that will be enjoyed, it is essential to start with a high quality product- either fresh or frozen.
Fresh fish should be purchased from well refrigerated or iced display cases where the fish is held at as near the temperature of melting ice as possible. This is true for all fresh fish items, smoked fish, salted fish which are not hard-dried, and marinated fish.
The surface of the fillets and steaks or the skin of dressed fish should be moist with no signs of drying. There should be a mild, pleasant odour, with no strong off-odours.
The flesh should be firm and elastic with no signs of it separating from the rib cage bones in dressed fish, or gaping (separation of the muscle segments) in fillets or steak products.
Frozen fish in any form should be solidly frozen and in intact packages. If the product is visible as through a clear plastic wrap, there should be no signs of drying or freezer burn and no accumulation of frost or ice crystals in the package (this is different from the presence of an ice glaze on the fish).
Any fish purchased as thawed, previously frozen should not be refrozen before use. It should be cooked and served or may be refrozen after cooking.

THAWING FROZEN FISH
Thawing the fish partially or completely before cooking is necessary when other preparatory steps such as stuffing a dressed fish, separating fillets for skinning or breading, marinating steaks or fillets, and cutting fish into pieces for chowders or stews are involved.
Schedule thawing so that the fish will be cooked soon after it is thawed. For best results in flavour and texture, do not hold thawed fish longer than a day before cooking.

How To Thaw Fish:
1. In the refrigerator
Place fish in closed container or well wrapped package in the refrigerator for 18 to 24 hours for a 450 g (1 lb) package.
2. In cold running water
For more rapid thawing, place whole dressed or pan-ready fish in a deep container, cover with cold water and place container under a slowly running cold water tap for 1 to 4 hours. For steaks or fillets, first place them in a water tight wrapping, then allow 1 to 2 hours for a 450 g (1 lb) package to thaw completely.
3. In the microwave oven
Wrap fish loosely in waxed paper or place in covered dish or leave in unopened package. Thaw on LOW or DEFROST for 4 to 6 minutes per 450 g (per lb). Stop oven halfway through timing period in order to turn package, then complete thawing. Let stand 5 to 10 minutes. Rinse fish under cold running water.
Thawing at room temperature or by immersion in hot water are not recommended as these methods increase the amount of moisture loss. Thawed fish should not be refrozen before cooking because this will damage the flavour and texture.

COOKING FISH
Most cooking methods will work well for most species. Although some recipes call for specific species of fish, others can usually be substituted with excellent results. Other more important considerations in the selection of a cooking method are:
- the size of the fish (for example, a 200 g dressed rainbow trout may be pan-fried but a 1-kg dressed whitefish is better stuffed and baked or poached);
- kind of preparation (for example, dressed, pan-ready, fillets, etc.);
- the time available for preparation;
- the purpose of the meal (for example, a formal dinner or a family supper);
- any restrictions on the calorie level in the final product (for example, choosing broiling or poaching over batter coating and deep frying).
Fish may be prepared by a wide variety of techniques. These are most easily classified by the method of transferring the heat to cook the fish:
- through air by radiant heat: the dry heat methods of baking, broiling and barbecuing;
- through water or steam: the moist heat methods of poaching, steaming, oven-steaming, braising and stewing;
- through fat: the frying methods of deep frying, pan frying and stir frying;
- through absorption of microwave energy in a microwave oven.

Preparing Fish for Cooking...

SCALING
Scaling should be done after fish are dressed because scaling whole fish can rupture viscera and result in unnecessary contamination.
Scaling may be done on a cutting board or, to prevent scales from scattering, in a sink under running water.
Hold dressed fish firmly by the tail with one hand and with the other remove scales by pushing a knife forward with the blade in a nearly flat position under the scales, taking care not to cut the skin. (A fish scaler may be used).
Wash fish under clean, cold, running water to remove loose scales.
This method of scaling produces the whole dressed fish. Further trimming away of the head and all fins results in pan-ready or pan-dressed fish.

1. Whole dressed fish
Remove any scales and, if desired, trim away the fins and head. Wash well inside and out under cold running water and pat dry. Make shallow, diagonal incisions across sides and one along the back to minimize distortion caused by shrinkage of the skin during cooking.
2. Pan-ready fish
Remove any remaining scales, wash well inside and out under cold, running water and pat dry. Make shallow, diagonal incisions across sides and one along the back.
3. Fillets or steaks
Use directly from frozen for some recipes, or thaw partially or completely. In any case, rinse well with cold water and pat dry.

FILLETING AND SKINNING
Place dressed fish on cutting board, with head to the right (left, if you are left-handed) and the back towards you. With a sharp knife, cut through skin and flesh behind the head to the backbone. Turn the knife to a flat position and cut with a sawing motion towards the tail, running the knife flat against the backbone. Turn the fish over and repeat the procedure to remove the other fillet.
To remove rib cage bones, lay fillet skin-side down with side containing bones to the left (right, if you are left-handed). Cut away ribs by exerting a slight upward pressure of the knife against underside of bones, taking care to remove as little flesh as possible.
Trim away the pelvic fin.
To remove skin, lay fillet in diagonal position holding tail end between thumb and forefinger of one hand. Cut down and under flesh, approximately 1 cm (1/2 in) from end of tail. Remove skin by cutting with a sawing motion, keeping blade flat while gripping the tail end of the skin securely.
Rinse skinned fillets, drain and pat dry with paper towels.

BONING DRESSED FISH
This is a method for removing almost all of the bones from a dressed and scaled or pan-ready fish which is to be prepared by baking, barbecuing, poaching, steaming, oven-steaming or smoking. The method is suitable for any of the fin fishes with the exception of the marine flatfishes and it can be used for any size fish.
Remove fins
With the tip of a sharp knife, make incision on each side of dorsal fin (along the back) and pull away fin and attached bones. Remove anal fin (at base of belly cavity near tail) by cutting on each side of the fin and pulling it away with the attached bones. With kitchen shears, trim away the pectoral fins (near the head) and the pelvic fins (midway along belly ) and trim the tail fin.
Remove backbone
Continue belly cut from anal vent to the base of the tail to expose backbone. Make shallow cuts to sever the join of ribcage bones on each side of the backbone. Then cut through top of backbone to separate it from the head. With fingers, push away the flesh from the small bones attached to backbone. Pull backbone out in one piece, using kitchen shears to snip it free from the tail.
Remove rib cage bones
Lay partially boned fish skin-side down, insert knife under ribs and then carefully cut away by exerting slight upward pressure of the knife edge against underside of bones so as to remove as little flesh as possible.

JUDGING "DONENESS"
Fish are best cooked rapidly at high heat. Because fish contains so little connective tissue, it does not require the extensive, slower cooking process necessary to tenderize it. The usual rule for judging doneness for any high heat method (except microwave cooking) is to measure the thickness of the fish through the thickest part and allow 5 to 7 minutes per cm (10 to 12 minutes per in) for fresh or thawed fish and 10 to 12 minute per cm (20 to 25 minutes per in) for frozen fish.
Avoid overcooking fish. It has the best texture and flavour at the point where it tests "done". This is where the flesh has just become opaque, with no translucency even in the middle of the thickest part and the fish flakes easily with a fork.
Cooked fish are delicate and tend to break apart easily. For best appearance, handle fish as little and as gently as possible during and after cooking.

BAKING
Baking is a dry heat method of cooking suitable for any form of fish, whole dressed, pan-ready, steaks or fillets and for both small and large fish.
Baking is done in an open dish or pan. If the container is closed or the fish wrapped in foil, the method is then called oven steaming. The surface of the fish tends to dry during baking: counteract this by brushing with melted butter or oil or covering with a sauce.

BROILING
This is a simple and rapid dry-heat method, suitable for steaks and fillets from large fish and for small pan-ready fish.
Fish for broiling are usually cut 2 to 3 cm (3/4 to 1-1/4 in) thick to prevent drying during cooking. Prepared steaks or fillets may be cooked from either thawed or frozen fish. When broiling frozen fish, however, the rack is placed farther from the heating element to prevent excessive darkening of the surface.
Fish may be prepared for broiling by marinating prior to cooking with a seasoned marinade of vinegar, lemon juice or wine and oil.
During broiling, fish are brushed with melted butter or oil or with a basting sauce (which may be the marinade). The broiler pan should be well greased to facilitate turning fish during cooking and removing cooked fish for serving.

BARBECUING
Barbecuing is a dry-heat method of cooking over hot coals. It differs from hot smoking in that the fish are cooked more rapidly and the flavour develops from other flavouring components added to complement the natural flavour of the fish rather than from prolonged exposure to smoke during smoke cooking.
This method is suitable for whole dressed and pan-ready fish, large and small, and for steaks or fillets from large fish either fresh or previously frozen and thawed.
In order to develop the barbecue flavour, fish are barbecued on an open grill or contained in a barbecue basket rather than being wrapped in foil. (Enclosing the fish in foil for cooking produces the product described under oven steaming.)
For best results and ease of handling, spray the clean, cold grill surfaces with a non-stick vegetable oil coating before placing the fish on the grill. Use a water-filled mist-spraying bottle to control any flaming caused by fat or marinade dripping on the coals. Minimize handling of the fish during barbecuing by only turning it once halfway through the cooking time.
Species appropriate for barbecuing as whole dressed fish include whitefish, tullibee, mullet, lake trout, bass, and northern pike.

POACHING
Poaching is a moist heat method which may be used for any form of fish: large and small fish as whole dressed, pan-ready, fillets, fillet portions, steaks and minced fish preparations such as quenelles or gefilte fish. Poached fish may be served directly as an entree or poaching may be the pre-cooking step for fish for casseroles, salads and sandwich fillings.
Fish is poached by simmering it in liquid at below boiling point (at 80° to 90°C/176° to 194°F). The size of the fish determines the cooking vessel needed. Steaks, fillets and small fish can be cooked in any covered vessel deep enough to hold a single layer of the fish plus poaching liquid. An electric frying pan is ideal because of its depth, shape and easily controlled temperature.
Larger fish require the use of a fish kettle - an elongated, deep, narrow pot with a removable, perforated poaching rack.

STEAMING
Steaming is an appropriate method for cooking any form of fish, large or small, as whole dressed, pan-ready, fillets or fillet portions and steaks. The fish may be prepared as a main course or this method may be used to precook fish for casseroles, salads, or sandwich fillings.
A fish kettle, as described in the poaching section, should be used for large fish. Smaller fish, steaks or fillets may be prepared in a steamer insert in a saucepan.
In preparing fish for steaming, large fish should be trussed as described in the poaching section.

OVEN STEAMING
This is one of the most convenient methods of cooking fish and can be done in an oven, over a campfire or on a barbecue. It is suitable for any form of fish, large or small as whole dressed, pan-ready, fillets or steaks.
Oven steaming is a combination of baking and steaming in which the prepared fish is sealed in foil or placed in a covered dish. The natural moisture of the fish forms the steam which cooks the fish and is retained in the sealed package.
Large fish may be seasoned or stuffed with a savory bread stuffing or finely sliced vegetables (green peppers, onion, celery, etc.). Small fish, steaks or fillets may be seasoned with salt and pepper and herbs such as basil, thyme, tarragon or dill.

BRAISING
This is a modified poaching technique used for fillets or steaks from large or small fish or for small whole dressed or pan-ready fish. The fish is combined with vegetables and herbs and simmered in a small amount of liquid later used to prepare a sauce. The vegetables used (carrots, onions, celery, etc.) are chopped fine and may be sauteed in butter beforehand.

STEWING
This moist heat method is suitable for skinless fillets or steaks from large or small fish. The fish is pre-portioned into appropriately-sized chunks.
Stewing is a method of simmering one or several kinds of fish with some vegetables and seasonings in a large amount of liquid which is part of the final dish. The fish may be served immediately when done with no further treatment required. Stewing includes the preparation of soups and chowders.

DEEP FRYING
Deep frying is suitable for skinless fillets or fillet portions from large or small fish and for very small pan-ready fish. Frozen fish should be thawed at least partially for even cooking.
Fish may be coated with either a leavened batter for a thick coating with a smooth crisp exterior finish, or with a breading yielding a thinner crunchy exterior finish.
Deep frying is done in hot oil or shortening at 190°C (375°F). Cook a few portions at a time so as not to depress the temperature of the oil. When the cooked portions are removed, the oil should be allowed to return to the frying temperature before adding other portions.

PAN FRYING
This method is suitable for large fish prepared as steaks or fillet portions or small fish as whole dressed, pan-ready or fillets and formulated products such as fish cakes.
Fish should be either completely or partially thawed before cooking to allow precoating.
Prepared fish cakes may be cooked from frozen.

STIR FRYING
Stir frying is suitable for skinless fillets or steaks preportioned into small bite-sized pieces.
It is the Chinese method of rapid cooking over high heat using a small amount of vegetable oil in a deep-sided, curved-bottom cooking vessel called a wok.