Vol. XVI · Moist Heat Plate 4 of 11braising, collagen, gelatin, tough cuts, beef shin, short ribs, liquid temperature, low oven, next day, 炖MT

Braising.

A braise at a bare simmer is tender in about three hours. At a rolling boil it is tender only an hour sooner, and drier.

Tough cuts — shin, shoulder, cheek, short ribs, oxtail — are full of collagen, the connective tissue that makes them chewy (VI.6). Held hot and moist, collagen slowly unwinds and dissolves into gelatin, and the meat falls apart in rich, sticky juices. The reaction speeds up with temperature, so a braise just below the boil, 90–95 °C, is tender in a few hours, and one at 70 °C takes a day (as sous vide does, XVI.7).

But the muscle fibres between the collagen do not get better with heat: past about 70 °C they squeeze out most of their juice (VI.5). A braise therefore trades collagen conversion against fibre dryness, and the best answer is gentle: liquid at a bare simmer, not a boil, in a covered pot in a low oven (about 150 °C oven for liquid near 95 °C) or on the lowest flame, with the meat half to two-thirds submerged. The dissolved gelatin, not the meat's own juice, is what makes a braise taste moist. The workshop braises shin.

Below: the share of collagen converted to gelatin against hours at the liquid temperature you choose (course rate), with a rolling boil and a gentle low-temperature braise for comparison, and the hours to tenderness (90 % converted).

What you will learn
Workshop
Course reaction rate for collagen to gelatin (0.010 per minute at 90 °C, activation energy 65 kJ/mol); tender taken as 90 % converted. The meat is assumed to be at the liquid temperature, which it reaches within the first hour for typical pieces.

Below the boil, and patient

In this model collagen reaches 90 % conversion in about 3.2 hours at 93 °C, 2.2 at a rolling boil, 5.2 at 85 °C and 10 at 75 °C. The boil saves only about an hour over a bare simmer, while churning the meat, clouding the liquid and driving the fibres hotter for no gain — which is why a braise is held just below the boil, and why an oven, whose heat comes in gently from all sides, makes it easy.

Method: brown the meat well (VIII.1) and set it aside; soften aromatics in the same pot; deglaze (VIII.7); return the meat with liquid to come half or two-thirds up; bring to a simmer, cover and put in a 140–160 °C oven or on the lowest heat; check after two hours and then every half hour with a fork. A braise is often better the next day: cooled in its liquid, the meat reabsorbs some of it, the fat sets on top and lifts off, and the flavours blend; reheat gently. Chinese 炖 and 焖 follow the same rules, often with the pot sealed.

At the stove

Braise two pieces of the same shin in the same liquid, one at a bare simmer in a low oven and one boiling on the hob, for the same time. Compare tenderness and how dry the fibres taste.

The French braisière was a lidded pot set in the embers with more coals heaped on its lid, so it heated gently from above and below — an oven before kitchens had ovens.

Terms

Braising
Slow cooking in a little liquid in a covered pot below the boil.
Collagen
Connective-tissue protein that dissolves to gelatin with long moist heat.
Gelatin
Dissolved collagen, which gives braises body and moistness.
炖
Chinese slow simmering in a covered pot.
Braising melts collagen into gelatin; keep the liquid just below the boil — boiling speeds it only modestly and dries the fibres. Often better the next day.

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.