Brown stock is one of the basic stocks (fonds) in French cuisine. Auguste Escoffier gives a recipe in Le Guide culinaire which contains marrow bones, beef, poultry carcasses, carrots, turnips, leeks, celery, parsnips and onion and is simmered and skimmed for several hours producing a dark brown liquid which is the basis for many other sauces, soups and stews. It is the basis of Espagnole Sauce and Demi-glace.
How To Make Beef Stock
1. Place Bones in Roasting Pan
Beef stock (often referred to as “brown stock”) starts with bones, and since we’re making a brown stock, we’ll want to use beef or veal bones. Veal bones are particularly desirable because they have more cartilage, which adds body to the stock in the form of gelatine.
Most supermarkets sell soup bones, but just ask the butcher if you don’t see them displayed. The best bones to use are the so-called “knuckle” bones from the various leg joints, because of their high cartilage content. Calves feet are also frequently available, and are another good source of the proteins that form gelatine.
The bones should be cut up — pieces 7 – 10 cm long should be about right. The same goes for calves feet, if you’re using them. If the bones aren’t cut up yet, ask your butcher to do it for you.
Arrange the bones in a heavy roasting pan. You can drizzle them with a bit of vegetable oil if you like.
2. Roast Bones for about 30 Minutes
Roast the bones in a hot (200°C) oven for about half an hour. They should be moderately browned by this point. It’s this roasting process that contributes much of the finished stock’s brown colour.
3. Add Mirepoix to Roasting Pan
Now you’ll add a mixture of chopped up aromatic vegetables called mirepoix (pronounced “MEER-pwah”). Mirepoix consists of 50% (by weight) onions, 25% carrots and 25% celery, and you want about 500g of mirepoix for every 2 kg of bones. So for 2 kg of bones you’ll need 250 g of onions and 125 g each of carrots and celery. Chop them roughly but more or less uniformly in size.
Add the mirepoix to the pan and return it to the oven for another 30 minutes.
4. Continue Roasting Bones with Mirepoix
Near the end of the roasting process add some form of tomato product — usually either tomato purée or tomato paste. The acid in the tomato helps break down cartilage, and the tomato also adds colour to the finished beef stock. About one small (170g) can of tomato paste per 2 kg of bones is a good measure.
5. Place Roasted Bones in Stockpot
Once the bones are thoroughly browned, remove them from the pan and place them in a heavy-bottomed stockpot. You can deglaze the roasting pan by pouring a bit of water into it and scraping up all the little roast bits.
6. Cover Bones with Cold Water
Use about a litre of cold water for each 500 g of bones. It’s important to use cold water, too — it helps in dissolving the collagen that goes on to form gelatin. And filtered water is great, too, if you have it. The fewer impurities you start with, the fewer you’ll have to cook out later. One of those charcoal water filters is perfect.
7. Add Mirepoix and Sachet
Next, add the mirepoix from the roasting pan, along with the deglazing liquid. Now is also the time to add a sachet d’epices, which is a small cheesecloth sack of dried and fresh herbs and spices. The standard contents of the sachet are dried thyme, fresh parsley stems, a bay leaf, several whole peppercorns, and a few whole cloves.
Bundle these ingredients into the cheesecloth and tie it up with cooking twine. Then tie the string to the pot handle for easy retrieval later.
8. Simmer 4-6 Hours, Skimming Impurities From the Surface
Bring the pot to a boil and immediately lower to a simmer. A violent, rolling boil will interfere with the clarification process and result in a cloudy stock. Keep it at a nice, gentle simmer, just below the boiling point. If you want to measure it with an instant-read thermometer, a simmer is anything between 85°C and 95°C.
By the same token, you don’t want to stir, either. Just let the stock simmer away. While it simmers, you’ll want to gently skim off the frothy scum that rises to the top — cooking out these impurities is part of the clarification process.
Continue like this for 4 to 6 hours. The longer you simmer, the more flavour and body is extracted from the bones. Keep track of the liquid level, too. Your goal is to wind up with about 4 litres of water for every 5 litres you started with. So if the liquid is evaporating too quickly, you can partially cover the pot, and add more water if necessary.
Over the course of several hours, the beef stock will have taken on a rich, brown colour. This is exactly what you want. And if you’ve done this right, the stock will also have a nice clarity. It shouldn’t look cloudy.
Strain Stock Through Cheesecloth and Chill
Strain the finished beef stock through a cheesecloth-lined mesh strainer. You can save the bones for making remouillage (French for “rewetting”), a weak stock made from bones that have been used once.
Finally, it’s important to cool the finished stock to 20°C within one hour to prevent the growth of bacteria.
A good way to do this is to fill a sink with ice water and lower the entire pot of hot stock into the ice bath. Stir the stock to speed cooling. Once it reaches 20°C, transfer the stock to the refrigerator where it will keep for 2 to 3 days.