Actually very easy

Bone broth

The beliefBone broth is assumed to be something different from ordinary stock, a near-miraculous drink.

The truthBone broth is a long-cooked stock: the difference is time and the amount of gelatine. This page credits it with no health effect.

10 hours

How to make it

What you need

2 kg beef bones (a mix of marrow, joint and cartilage pieces)
4 litres of cold water
1 onion, 1 carrot, half a celeriac
1 tablespoon of vinegar
2 bay leaves, 10 black peppercorns

How the engine read this list (8 lines)

—	Beef bones	no record
4000 g	Cold water	water
150 g	Onion	onion
70 g	Carrot	carrot
250 g	Celeriac	celeriac
15 g	Vinegar	vinegar
0 g	Bay leaves	bay-leaf
—	Black peppercorns	black-pepper

An empty weight means that line could not be turned into grams — either the amount is open ("to taste") or the ingredient has no record here. Neither enters the sum as zero; they do not enter it at all.

Spread the bones on an oven tray and roast them at 220 °C for 40 minutes, until browned.
Move the bones into a large pan with the cold water and vinegar. Loosen the browned bits on the tray with a little hot water and add them too.
Bring it slowly to just below the boil, skim the foam and turn it down to 90–95 °C, with only the odd bubble.
Cook it 8–12 hours, topping up with hot water if the bones start to show. Add the vegetables and spices in the last hour.
Strain through a fine sieve, divide into small containers and get it into the fridge within two hours. Lift off the fat the next day.

Why it works

Beef bones, especially joints, cartilage and feet, are high in collagen. Collagen is a triple-helix protein, and above 70 °C the helix unwinds into chains of gelatine; but beef’s thick, cross-linked collagen converts far more slowly than chicken’s. That is why bone broth cooks for 8–12 hours. The result is a jelly firm enough to cut with a knife in the fridge. Roasting the bones first at 220 °C gives a dark colour and a roasted taste through the Maillard reaction. Adding a tablespoon of vinegar is common too; it is said to draw minerals out of the bone, but when the calcium drawn out has been measured it has come out very small, and this site gives no figure for it. Keeping the heat at 90–95 °C for the long hours matters: a boiled broth turns cloudy and its fat mixes into the water.

The rough sum

4486 grams going in

198 kcal in total

100% of the mass has figures behind it. This is the sum of what GOES IN rather than of what comes out. Wherever something evaporates, drains or ferments the two differ: a kilo of milk is 150 g of cheese.

Diets it qualifies for

Gluten-free Vegan Vegetarian Lactose-free

Storage & shelf life

How long it keeps

Fridge, 0–5 °C: 48 hours
Freezer, in portions: 6 months
Room temperature: At most 2 hours to cool

A big pan of liquid cooked for hours stays warm for hours after it comes off the heat, and that is the best range there is for bacteria. The UK Food Standards Agency advises getting cooked food into the fridge within one to two hours; with bone broth that is not possible without dividing it into small containers. The layer of fat that sets on top protects the flavour but does not extend the safety limit.

When to bin it A sour smell, foaming, or the set jelly turning watery: throw it out.

History

Where it comes from

Boiling bones for hours is as old as fire: getting the fat and gelatine out of the bone was how hunting peoples wasted nothing of an animal. In Turkish cooking, paça, tripe and sheep’s-head soups come from the same logic, and are drunk on winter mornings and after long nights. The fashion for “bone broth” under that name began in the United States in the mid-2010s.

The knack

If ten hours on the hob does not suit you, a covered pan in a 100 °C oven works too: the liquid stays calm and never reaches a rolling boil.
Kept as a set jelly, bone broth is the richest base for sauces and pilaf: a tablespoon pulls a pan sauce together.

The pantry