Vol. XVIII · Meat and Poultry Plate 4 of 11brining, dry-brining, salt, myosin, water retention, diffusion, brine strength, salting ahead, turkey, pork chop, 腌MF

Brining and Dry-Brining.

A pork chop that sat in salt water for four hours loses less juice and is seasoned inside. The salt did it by creeping a few millimetres in.

Salt does two things inside meat. It seasons. And at around 1–2 % in the muscle, it partly dissolves myosin and loosens the filaments, so the fibres swell, take up water and contract less when cooked (VI.5): brined meat can lose several percentage points less of its weight. But salt moves in only by diffusion (III.8), and diffusion through muscle is slow — a few millimetres in an hour, about a centimetre in a day. Thick pieces need long brines, and their centres may never be salted.

A wet brine is salt water, typically 3–8 %, the meat submerged and refrigerated; it adds water as well as salt, and too long or too strong makes the meat spongy and ham-like. A dry brine is salt rubbed on the surface, about 1 % of the meat's weight, left uncovered in the fridge for one to three days: the salt draws juice out, dissolves in it to make a concentrated brine on the surface, and is slowly reabsorbed — no added water, a drier surface for browning (VIII.2). The workshop soaks a 25 mm chop.

Below: the salt concentration across a 25 mm pork chop after the hours you choose in a brine of the strength you choose at 4 °C (diffusion, exact for the slab with a teaching diffusivity), and the average salt it has taken up over time.

What you will learn
Workshop
Fick's law in a slab of 25 mm, both faces in brine at 4 °C, with a diffusivity of 4 × 10⁻¹⁰ m²/s (teaching value in the published range for salt in pork). Concentrations are as % salt in the meat's water phase relative to the brine; water uptake and the meat's own salt are left out.

Hours for a chop, days for a roast

In a 6 % brine the chop's average salt reaches about 0.48 % after one hour, 0.97 % after four, 1.67 % after twelve and 2.37 % after a day — so a chop needs a few hours, and a day makes it ham. The profile shows why: the outer few millimetres are salty long before the centre gets any. A thick roast or a whole turkey takes days; brine weaker for longer, or dry-brine, so the outside is not over-salted by the time the inside is reached.

Practical recipes. Chicken pieces and pork chops: 5–6 % brine for 2–4 hours, or dry-brine at 1 % of their weight overnight. A whole chicken or a pork loin: dry-brine 1 % for 1–2 days. A turkey: 1 % dry-brine for 2–3 days, uncovered, which also dries the skin for crisping. Rinse wet-brined meat and pat it dry; do not salt it again. Sugar in a brine adds flavour and browning but does not help water retention. Chinese 腌 for stir-fries is the fast version: a pinch of salt, wine and starch for 15 minutes on thin slices, where diffusion has only a millimetre to go (XVIII.6).

At the stove

Dry-brine one chicken leg at 1 % salt overnight, uncovered, and leave another unsalted. Cook both the same way and compare juiciness, seasoning and the crispness of the skin.

Brining turkey for Thanksgiving became popular in the United States in the 1990s after food writers tested it; dry-brining spread later, following the Zuni Café in San Francisco, whose chef Judy Rodgers salted chickens days ahead.

Terms

Wet brine
Salt water the meat soaks in.
Dry brine
Salt rubbed on the surface and reabsorbed over a day or more.
Diffusion
Movement of a dissolved substance from high to low concentration (III.8).
Water retention
How much water meat keeps when cooked.
Salt in muscle loosens myosin, so the fibres hold more water and meat is seasoned inside. It moves by slow diffusion: hours for chops, days for roasts. Dry-brining adds no water and dries the surface.

Sources

  1. A teaching value chosen for the course: the right order of magnitude and shape, not a measurement of a particular food.
  2. H. McGee, On Food and Cooking: The Science and Lore of the Kitchen, 2nd ed., Scribner, 2004.