Order, deliberate#

Chicken and fish are the primary material this week; duck is touched on briefly as a point of contrast.

• anatomy first — so the reason a cut behaves the way it does is visible before any handling instruction is given
• handling second — so the anatomy explains the rule rather than the rule sitting on its own

The bird: leg and thigh versus breast#

• leg and thigh work constantly — walking, standing, bearing weight
• more connective tissue, more slow-twitch, myoglobin-rich fibre (“dark meat”)
• the breast, in a bird that does not fly far, does comparatively little work — leaner, paler
• fat sits mostly under the skin, not running through the muscle

Duck, briefly#

A bird bred for sustained flight or cold-water swimming differs mainly in degree:

• thicker subcutaneous fat layer
• darker meat across the whole carcass, including the breast
• meat only, raw, per 100 g: 135 kcal, 5.95 g fat, 18.28 g protein, 2.4 mg iron (FDC ID 172410) — more than six times chicken breast’s iron, consistent with dark meat running through the whole bird

Fish anatomy#

Fish have no need to support their own weight against gravity.

• connective tissue is thinner than in poultry or red meat
• muscle is arranged in short segments (myotomes), not long fibres
• this is why fish flakes apart along clean lines under far less force
• fillets are portioned along those natural seams, not cut across them

Fish portion forms#

Portion form follows the same seams. A fillet runs the length of one side of the fish; a steak (or darne) is a cross-section through the whole fish, backbone included; a supreme is a skinless, boneless fillet portion. The pin-bone line — a row of small bones down the centre of each fillet — is a separate anatomical feature from the myotome seams that set where a fillet can be taken cleanly.

Fish, checked before it is bought#

A fish’s anatomy is what a freshness check actually reads. Four checks, each traceable to a visible or smellable change as the fish ages:

• eyes — clear and shiny when fresh; cloudiness is the sign to refuse
• gills — bright red when fresh; dulling toward brown or grey marks decline
• flesh — springs back when pressed; flesh that stays indented has already begun to break down
• smell — mild, of the sea; ammonia or sourness means the fish should be refused, not just discounted

Eyes and gills together, on one fish#

No matched pair of a fresh and a declining fish, comparably photographed, could be sourced — the epic’s own sourcing risk, realised. This single, labelled close-up names the checks it shows; it does not stand in for a comparison.

Scale condition, a fifth check, is not documented in the FDA source above; the freshness-grading standard on the next slide covers it.

What the grading standard adds#

The EEC freshness grading system used across European fish markets extends the same four checks with published wording, and adds scale and skin condition as a fifth:

• top-grade eyes are described as convex; the flattest, most sunken eyes and greyed, opaque corneas mark the unfit end of the scale
• top-grade skin and scales are bright, shining and iridescent, loosening and dulling as the fish declines
• gill colour and odour move the same direction already named above

This is a grading standard, not a safety threshold — a fish graded below top quality is not automatically unsafe — but the direction of every change matches the FDA checks above.

Cold chain#

Raw poultry and raw fish are both perishable enough that the two-hour rule applies:

• never left out of refrigeration more than 2 hours
• more than 1 hour if the ambient temperature is above 32 °C
• bacteria common to raw poultry and seafood grow fastest between 4 °C and 60 °C, and can double in as little as 20 minutes within that band

Cross-contamination#

A cutting board and knife used on raw poultry or fish should not touch produce, or anything already cooked, without being washed first.

• hot, soapy water, a clean rinse, a full dry — or a dishwasher cycle for a nonporous board
• the point is not fastidiousness: the same organisms that make raw poultry and fish perishable transfer readily to whatever the board touches next

Portioning#

Work with the anatomy already established, not across it.

• poultry — broken down along the joints, where connective tissue is thinnest, avoiding splintered bone
• fish — portioned along the myotome seams and away from the pin bones

What the eight-piece breakdown costs#

Jointing a whole bird into leg, thigh, drumstick, wing and two breast halves does not shorten the refrigerated window — FDA’s storage chart holds whole poultry and poultry parts to the same 1–2 days at 4 °C or below. What it does shorten is frozen quality life: about 9 months for parts against about 1 year for a whole bird, the same figures already on this week’s poultry storage table.

No equivalent figure is documented for fish portion form. FDA’s chart distinguishes fish storage by fat content — lean versus fatty — not by whether the fish is left whole or cut into fillets or steaks, so no holding-time cost is claimed for fish portioning here.

Poultry#

The 4.4 °C line is a target to verify, not to assume — an appliance thermometer left on the shelf is the only way to know the refrigerator itself is holding it, rather than trusting the dial on the door.

Fish and shellfish#

• same 1–2 day window under refrigeration
• onto ice or into the fridge within 2 hours of purchase
• 1 hour if the ambient temperature is above 32 °C

These are food-safety limits, not cooking instructions — this week teaches a student to read the storage clock, not to cook against it.

Fat, protein and calories per 100 g#

Raw, from USDA FoodData Central — the same database the invent-a-recipe assessment names, and the same four materials Session 3’s tutorial ranks.

Why salmon’s figure is higher#

Salmon’s higher fat figure is consistent with the anatomy already covered: a cold-water swimmer stores more fat through its flesh than a bird whose breast, in particular, was bred to do comparatively little work.

Iron, and the same dark-meat story again#

A second nutrient, read off the same four USDA entries:

Duck — dark meat across the whole carcass — carries by far the most iron; chicken breast, the leanest, whitest muscle at this table, carries the least. The two fish sit close together in between, without the light-meat/dark-meat split that separates the two birds.