User:Kittycataclysm/Sandbox/Fish

Kittycataclysm/Sandbox/Fish
Category	Seafood

Cookbook | Recipes | Ingredients | Equipment | Techniques | Cookbook Disambiguation Pages | Ingredients | Basic foodstuffs | Seafood

Fish, or fin fish to distinguish from shellfish, are bony, non-mammalian sea creatures. They come in many different varieties.

fish can have lots of different names even in same language

lots of common names for fish; sometimes renamed for commercial/marketing reasons

fish have many names

Characteristics

Structure

Typically, the basic structure of fin fish is conserved. Many, if not most, fish have fins and tails. They have a central backbone and ribcage, with slabs of muscle on either side of these, and sometimes tiny pinbones throughout the flesh. Fish bones are much softer than those of terrestrial animals like cows or chickens, though they are still unpleasant to eat. Freshwater fish tend to have many smaller bones, while saltwater fish tend to have fewer, thicker bones.

Shape

Fish are usually divided into two main classes: roundfish and flatfish. Roundfish are tubular in shape, swim vertically, and have one eye on either side of the head. On the other hand, flatfish are pancake-like with flat, oval bodies. They have dark skin on the side facing up and light skin on the bottom. They swim horizontally, and both eyes are on the top side of their bodies.

Fat

The fat content of fish ranges from 0.5–20% across all species. Compared to land animals, fish have much less intermuscular fat, and lot of it is located under the skin and around the belly area. Lean fish are relatively low in fat, while fat fish have higher amounts on average. In addition, fat fish are typically more intense in flavor than lean fish.

Color

The color of fish flesh depends largely on the animal's lifestyle, including environment and diet. The majority of fish have white/light flesh low in myoglobin, as they are supported by the surrounding water and don't need endurance muscle. Their dark flesh, if present, is typically limited to a thin layer just under the skin and sometimes along their center line. On the other hand, active long-distance fish like tuna have significantly more red flesh. The distinct pink color of salmon flesh comes from the pigmented crustaceans in their diet. All fish flesh starts out translucent when raw and becomes opaque with exposure to heat or acid.

Flavor

Fish flavor depends on species, muscle type, salinity, fat content, and diet. Freshwater fish have a milder flavor because they accumulate fewer amine-containing compounds in their flesh, and they aren't exposed to bromophenols, which provide a distinctive "oceanic" character. High-myoglobin fish like tuna may have a flavor tinged with iron. High-fat fish carry more flavor in their flesh than do lean fish.

Texture

Fish muscle fibers are folded over on themselves and separated by connective tissue, which gives the flesh a flaky texture when cooked. Compared to that of land animals, fish flesh is very delicate in texture, largely due to its weaker and less prevalent connective tissue. Fish muscle fibers are shorter, and their collagen turns to gelatin and dissolves around 46–55°C (115–131°F). As a result, fish is easy to overcook and toughen—as the flesh is heated, the gelatin renders out, the muscle fibers coagulate, and ultimately moisture is squeezed out of the flesh, making it dry. Because the collagen (by way of gelatin) provides a sensation of moistness, the tail area, which is rich in collagen, feels more succulent. By the same principle, fish lower in collagen feel drier overall. Certain fish have life cycle stages that negatively impact the quality of the flesh, which becomes spongy and unappetizing in texture. Fish bones are soft and become softer when cooked near boiling temperature.

Cuts

Fish doesn't have the same diversity of cuts as, say, beef. However, it is classified differently based on the degree to which it has been broken down. The following terms describe fish in different processing stages:

• Whole: completely intact fish just as it was slaughtered
• Drawn: guts removed
• Dressed: drawn with scales, fins, tail, and sometimes head removed
• Steak: cross-sectional slice of the fish, often containing a piece of spine
• Fillet: only the meaty side of the fish, either with skin or without
• Butterflied: fillets still joined together, usually at the back, and opened flat like a book
• Sticks: simple vertically sliced skinless fillet
• Tranches: fillet diagonally sliced to give pieces with large surface area

Selection and storage

The first step to fish selection is to understand responsible and sustainable fishery. Many species of fish worldwide are over-fished or poorly managed, which can have negative environmental impacts. Check a reputable source such as the Monterey Bay Aquarium's Seafood Watch service to make sure you are choosing fish from a well-managed fishery. Your fishmonger should also be able to tell you detailed information about the fish, including where it is sourced from, how it was caught, how it has been processed/stored, and when it was delivered, if applicable. When available, try replacing unsustainable fish with similar but more sustainable varieties.

When purchasing fish from a vendor, there are several factors to assess in order to make sure you are getting good quality fish. Starting at the surface, the skin and fins should be moist, shiny, and clean, with no bruising, discoloration, or stickiness. If present, the scales should be intact. Any slime, if applicable to a given species, should be clear and not cloudy. The gills should also be moist and bright red/pink in color, not a duller rusty or brown color. The eyes should be rounded and shiny, not sunken and dull. If the fish is whole, there should be neither bloating or discoloration near the belly. If gutted, make sure there is no indication of belly burn. If the vendor lets you touch the fish, the flesh should feel firm and spring back after you remove your hand. There should be no spongy texture or flaking of the flesh. If they let you smell the fish, it should not smell of ammonia, sulfur, or other spoilage. At most, it should smell of the sea in the case of ocean fish. Ideally, the fish should be stored on ice and should not be touching any other fish in the case.

Fish is extremely perishable, with cold water species spoiling even faster than warm water species. Fish should be gutted as soon as possible after slaughter to prevent degradation of the flesh. Under perfect refrigeration conditions and with optimal processing, fish will last up to 10–12 days after slaughter. Subpar conditions shorten this shelf life, and in many cases purchased fish is only good for a handful of days under refrigeration. The optimal way to store fish is on flaked or crushed ice in the refrigerator—this keeps them as close to freezing as possible. Whole roundfish should be packed in ice in the "swimming position", which is to say with the backbone facing the sky. Flatfish should be packed at an angle with their dark side facing down. Fillets and other smaller cuts should be wrapped in plastic when packed in ice. Ideally, the icing should be done in a perforated tray to allow the melted ice to drain away from the fish and prevent pooling next to the flesh. The next-best way to refrigerate fish is in a refrigerator set to 0°C/32°F. A 40°F fridge is least preferable.

Modern freezing technology has made freezing fish a very viable option for extended shelf life without much loss in texture or flavor. The best way to freeze fish is with a cryogenic substance such as liquid nitrogen—this quickly freezes the fish, forming very small ice crystals, which avoids damaging the texture. Blast chilling is also a good option. To freeze fish at home, cut it into portions no thicker than 2 inches (5 cm), seal it in a plastic bag with no air (vacuum is ideal), and submerge it in several inches of cold water before placing in a standard freezer—this significantly reduces the risk of oxidation and ensures a slow thawing. Store frozen fish below 0°F (–18°C), and thaw it in the fridge to reduce the risk of ice crystals puncturing the adjacent flesh and damaging the texture. Thawing under cold running water is also an option if necessary.

Canned fish is often good, but very different in taste, and selection is limited. Canned salmon and anchovies are particularly high in calcium, because the bones are softened by canning and are eaten with the flesh.

good fish:

• knife should cut, not pull, through fish

fishy smell is sign of aging/decomposition; fresh fish "tastes and smells sweet and fresh"

raw seafood should be very fresh and from saltwater (fewer parasites); freezing and thawing kills parasites; keep cold and handle little

red fish flesh vulnerable to oxidation and needs to keep very cold for long-term storage

fat fish keeps shorter than lean

purchase fish as close to serving as possible; refrigerating on ice in perforated pan is best; don't soak in water; store belly down; exposed flesh wrapped in plastic

buy fish as close to serving time as is feasible

buy very fresh fish that has been properly handled the entire time

bad fishy smell comes from microbial degradation

fishy smell comes from breakdown of amine and sulfur compounds; very slight fishy smell is acceptable and not harmful; significant smell is bad

with only very slightly fishy fish, try washing and adding acid; don't bake, broil, or fry

bacteria+enzymes convert TMAO to stinky TMA, urea to ammonia (bad old fish smells)

surface TMA washed off; acid makes it less volatile

Preparation

Filleting

round fish usually make 2 fillets; flat can have 2–4 depending on size

start filleting flat fish on light side to prevent crushing

flatfish 4 fillets; round fish 2 fillets

Deboning

remove pinbones with pliers or tweezers

to scale: scrape tail to head with fish scaler or knife back; don't push too hard; rinse well

if necessary, remove pin bones with tweezers or pliers

to skin: place fillet skin down, start at tail, angle knife towards skin, grip skin, smooth sawing,

remove guts asap after death: cut from anal opening to gills; careful not to puncture organs --> cut out guts by tail and right behind head --> use spoon to remove large vein and residual guts --> rinse

scale fish by running scaling tool (specialized or knife back) from tail to had; don't bruise; under running water is best

Use

large fat fish and strong flavored fish can get overly greasy when cooked in fat.

lack of fat makes easy to dry out and vulnerable to overcooking

poaching is good for lean fish bc it preserves moisture

if broiling/baking lean fish, baste it and be careful not to overcook

lean fish do well when fried and benefit from added fat

fat fish work well with moist cooking, broiling, baking, grilling

how to tell if fish is done:

• starting to flake doesn't flake easily
• flesh separates from bone
• flesh goes from translucent to opaque

fish livers sometimes eaten (e.g. red mullet, monkfish, mackerel, some rays, and the cod family)

carp and cod tongues are eaten

fish heads eaten often in asia in soup or fried

tartare: chopped raw fish

carpaccio: sliced raw fish

seviche: raw fish in acid to coagulate it; note it's not actually cooked

sushi: rice, often with raw fish

brush all fish with oil before grilling or broiling

fatty fish best for baking; lean must be basted

fish flesh is delicate due to flaking

lean fish good for steaming

sous vide cooks thoroughly without overcooking

broiling/grilling work well for all fish but especially fat fish; broiling better for delicate fish

sautéeing works well for all fish; keep uniform and thin; put in hot pan; don't crowd—it will steam and not brown

en papillote: wrap in parchment and bake to steam

lean fish good for breading and deep frying; fat fish good for croquetes

searing then baking fish helps brown it but cook it through

fat fish good for baking because harder to dry out; lean fish must be basted

fat fish good for broiling but must be greased

lean fish good for dredging before broiling

lean fish good for sautéing and deep frying, which adds fat; fat fish runs risk of over greasy

large fish can be browned in pan then finished in oven—brown presentation side (often flesh side) first

papillote: fish + other ingredients in parchment to keep moisture and aroma inside

don't pressure cook fish—easy to toughen

fish balls are made in multiple places (e.g. norway and malaysia

done when:

• flesh is opaque and firm
• flesh separates from bones
• flesh starts flaking/separating but not too easily

overcooking is common problem

remember about carryover cooking

gentle cooking required, easy to overcook; some fish tolerate more heat, but still delicate

fish doesn't usually need resting after cooking

fish flesh is more flavorful when bones left in

head and bones are good for stock

Moist heat preserves not creates tenderness.

Cooked fish flakes apart and falls apart easily.

overcooking fish makes muscles over-coagulate; shrinks and toughens, excess water loss

excessive coagulation pushes out water and makes dry + chewy

fish is cooked at lower temp since its collagen is weaker and breaks down at lower temps

lots of dried seafood production/consumption in china and southeast asia

two main ways to ferment fish: salt and leave to ferment vs salt and combine with fermenting carbohydrates like grains

sous vide cooks fish very tenderly and melt in mouth

sprinkling some salt on the pan can help prevent sticking

residual heat cooks fish beyond kitchen; cook to just underdone

fish cooks quickly

Fish is delicate and easy to overcook

Safety

While it is generally unwise to eat any fish raw, wild freshwater fish are particularly likely to carry parasites that can infect humans.

sashimi grade fish usually frozen if at risk for parasites, may be handled better vis a vis surface contamination risk

chemical pollutants in water can accumulate in fish

bacterial infection eliminated by cooking to 60°C/140°F; does not necessarily eliminate toxins produced by bacteria

botulism from poorly cold-smoked/salt-cured/fermented fish

ciguatera poisoning from contaminated tropical reef fish

parasites in fish flesh

fish for sushi should be very fresh with impeccable handling

for undercooked fish, use previously and sufficiently frozen fish: 7 days <–20°C (-4°F) or 15 hours <-35°C (-31°F) to kill parasites within flesh

fish to be eaten raw should be frozen to kill parasites

rare/med-rare cooking may not kill pathogens throughout fish flesh

big long-living fish (e.g. tuna, shark, swordfish) at top of food chain have high mercury accumulation

can effectively pasteurize medium rare fish that is held at 131°F / 55°C for long enough; does not work for rare

note that freezing doesn't kill bacteria, but those are usually on surface

Substitution

The following table indicates groups of fish that share characteristics and can often be reasonably substituted with each other:

White, tender, lean	White, tender to firm texture, lean to moderate fat	Light, some flavor, firmness, and fat	Darker, some flavor and firmness, fatty	Dark, strong flavor and firmness, fatty
Atlantic cod Dover sole Haddock Halibut Lake whitefish Pacific sand dab Pacific sole Spotted cabrilla Tilapia	American plaice Arrowtooth and starry flounder Butter, English, and rock sole Cobia John Dory Lionfish Sea bream Sea trout	Alaskan pollock Brook and rainbow trout Catfish Grouper Mahi­ mahi Pacific ocean perch Red snapper Skate White sea bass Wahoo/Ono	Arctic char (lake trout) Atlantic, coho, king salmon European Turbot Eel Herring Lake Chub Lake sturgeon Monkfish Pacific cod Pollock Striped bass Swordfish Vermillion snapper	Black sea bass Bluefish King mackerel Spanish mackerel Tuna

drying fish can cause oxidation --> lean fish better for this

don't handle fish until rigor is over—can cause tearing and mushiness

imitated fish should have skin left on; common fish often skinned; delicate fish keep skin on

flatfish fillets can be broken into fletches

can butterfly round fish and remove bones through belly

quickly cool fish after death in ice slurry

dry curing is best for lean fish; fatty fish are usually submerged and brined because of the fat oxidation risk

fresh not frozen fish is best for cold smoking fish

blast-freezing or IQF uses very cold moving air to quickly chill fish

cryogenic freezing uses <–238°F/–150°C liquid gas to quickly freeze fish; smaller ice crystals, better texture, better for high-heat cooking

redder fleshed fish have longer rigor mortis peaking around 6–8 hrs

white flesh fish have shorter rigor mortis peaking around 4.5–6 hrs

farmed salmon starts rigor around 10 hr for 60 hr duration