Cut · Leg bones, the fatty core

Bone marrow

Bone marrow is the soft, fatty tissue inside the long leg bones, mostly fat and led by oleic acid. Roasted cut side up at 220–230 °C / 425–450 °F, it puffs and starts to pull from the bone, ready to spread on toast; it also goes into broths and sits at the centre of an osso buco — caracú in Argentina, tủy bò in Vietnam.

Also known as: marrow bones · Tuétano · caracú · Tủy bò · TutanoLast reviewed 22 Oct 20265 sources

Yellow marrow, mostly fat

Marrow fills the hollow centre of bones. In young animals much of it is red marrow, which produces blood cells; in adult cattle the long bones of the legs are filled mainly with yellow marrow, a soft tissue made largely of fat cells. That yellow marrow is what cooks call bone marrow: pale, creamy when raw, and translucent and wobbling when heated.

Its composition explains its richness. Yellow marrow is mostly fat, with small amounts of protein and water, and the fat is predominantly monounsaturated, with oleic acid the main fatty acid, followed by the saturated palmitic and stearic acids. It is very energy-dense. As it heats, the fat softens at a lower temperature than beef suet, which is why roasted marrow becomes spreadable rather than staying firm.

Canoe-cut or cross-cut

Marrow bones come from the long bones of the legs, chiefly the femur (thigh bone) and the tibia and radius of the lower leg; the middle section of each bone, where the wall is thick and the canal widest, holds the most. Butchers saw them in two ways. Canoe-cut or "long-cut" bones are split lengthwise into two halves, each a trough of exposed marrow; they cook evenly and are easy to scoop. Cross-cut bones are sawn into rounds about 5–8 cm (2–3 in) long, with marrow at both ends.

Marrow also comes with other cuts. Each slice of shank cut for ossobuco has a ring of bone with marrow in the centre, and the larger vertebrae of the oxtail carry some too. Leg bones are not among the specified risk materials removed from food in connection with BSE; the controls apply to the brain, spinal cord and, in older cattle, the vertebral column.

Cooking it: 15–20 minutes in a hot oven

The simplest preparation is roasting. The bones go cut side up into an oven at about 220–230 °C / 425–450 °F for 15–20 minutes, depending on size, until the marrow has puffed, browned slightly on top and begun to separate from the bone, but before it melts away into the pan. It is seasoned with coarse salt and spread on toast. A dish of roasted marrow bones with a sharp salad of parsley, shallots and capers, served at a London restaurant from the mid-1990s and published in Fergus Henderson's Nose to Tail Eating (1999), became widely copied.

In Argentina and Uruguay the marrow bone is caracú. It goes into the puchero, the boiled dinner of beef, vegetables and corn, where the marrow is spread on bread, and cross-cut bones are also roasted on the parrilla, standing upright beside the embers until the marrow bubbles. French pot-au-feu traditionally includes marrow bones (os à moelle), wrapped so the marrow does not escape, and the marrow is eaten on toast with salt. Sliced, poached marrow also finishes sauces such as the Bordelaise.

Marrow bones are a base of broths. Long simmering extracts fat and flavour and, with knuckle bones, gelatin. Vietnamese phở broth is built on leg and knuckle bones (xương ống), and some phở shops serve pieces of marrow (tủy) as a topping; in Korea, sagol leg bones are simmered for many hours for the milky soups seolleongtang and sagol-gomtang.

Centre of the femur, pale and creamy

For roasting, look for bones from the centre of the femur, with a wide canal and marrow that is pale and creamy rather than grey or dark red. Canoe-cut bones are easier to cook evenly and to eat; cross-cut bones of 5–8 cm are better for broth and for standing on a grill. About 300–450 g (10–16 oz) of bone, two canoe halves or three to four rounds, makes a starter portion.

Marrow is perishable once the bone is cut and exposed. Fresh bones keep one to two days in the refrigerator and freeze well. Some cooks soak the bones in cold salted water for several hours before roasting to draw out blood and make the marrow paler, which is a matter of appearance rather than safety.

Names around the world

16

The same muscle, named by language and by trade system.

English	Bone marrow · marrow bones
Español	Tuétano · caracú
Tiếng Việt	Tủy bò
Português	Tutano
Français	Moelle
Italiano	Midollo
日本語	骨髄 (kotsuzui)
한국어	골수 · 사골

All the cuts' names, country by country →

Trade and national systems

System	Name	Reference
United States	Marrow bones · canoe-cut (split) · cross-cut	NAMP
United Kingdom	Marrowbone	AHDB
Argentina	Caracú · hueso con caracú	IPCVA
Brazil	Tutano · osso buco	Portaria 5/88
Mexico	Tuétano · hueso de tuétano	—
France	Os à moelle	Larousse
Korea	사골 (sagol, leg bones for broth)	KAPE
Vietnam	Tủy bò · xương ống	—

Frequently asked questions

Sources

5

1. McGee, Harold. On Food and Cooking: The Science and Lore of the Kitchen, rev. ed. New York: Scribner, 2004.
2. Larousse Gastronomique, rev. ed. London: Hamlyn, 2009.
3. North American Meat Institute. The Meat Buyer's Guide, 8th ed. Washington, DC, 2014.
4. Toldrá, Fidel (ed.). Lawrie's Meat Science, 8th ed. Duxford: Woodhead, 2017.
5. Henderson, Fergus. Nose to Tail Eating: A Kind of British Cooking. London: Macmillan, 1999.

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