Originally Posted by HitMan009
Can you be so kind as to put up the step-by-step process of making the authentic Demi-Glace?
I can give a truncated version. There are a lot of recipes out there for this. Most of them are variations on Escoffier. His recipe was itself both a standardization of competing versions, and a simplification. When you read it, you will be astounded that it could be called a simplification of anything. But older versions were really involved and complex (and expensive). Careme used whole game birds!
Anyway, you start by making a stock. That is "day one." To make stock, you roast meat and bones until they are well browned, then simmer them in water for at least five hours. You also simmer carrots, onions, celery, garlic, and an herb bouquet. Again, use half has much celery as you use carrot and onion. Say, four onions, six carrots, and two celery stalks.
What meat and bones you use is up to you. All beef is cheapest, and most readily available. It produces a deeply colored, robustly flavored stock. All veal is expensive as hell (even shank meat) and hard to find (the bones). The color is lighter, and the flavor less intense, but more complex. Most restaurant chefs prefer this to beef stock. Or you can use a mixture of both. I have had good results from doing this. Personally, while all-veal stock is a wonderful thing (especially for broths), for certain sauces, I don't find it dark or intense enough.
How much you need depends on how much liquid you want to yield, and the size of your stock pot. I recommend getting a huge pot. Really, the amount of work involved is the same either way, so you may as well yield as much as you can. A rough guide is, one pound of meat and bones per one quart of starting water.
Preheat an oven to 450. Put the meat and bones in a roasting pan, and put it in the oven. If using a lot, you will have to do this in two batches. Don't crowd the pan. Crowded pieces don't brown, they steam. Not good. You want to brown the bones and meat thoroughly. The bones will be pearly white when you put them in. They should be a deep caramel at least before you take them out. Take the pan out every 15 minutes or so, and turn the bones and meat to help even out the browning.
Now, the recipes diverge in a few points here. Some say to brown the vegetables. Some say, just dump them in when you add the liquid. Some say to simply cut them into eighths. Others say that a coarse chop is better. I agree about the coarse chop, and I also prefer to roast them. But not as long. Put them in toward the end of the process. Another trick is to rub the bones with tomato paste after they have browned about halfway (or more). This really deepens the color of the stock. It is not something the original French recipes say to do. My advice: if you want to use the stocks for fine broths, consumes, etc., don't do this. If you intend to make really hearty soups (like French onion), consider it. If the finished sauce is most important to you, then definitely do it.
When browned, dump the contents of the roasting pan(s) into the stock pot. By the way, there is no reason you can't split this between two stock pots if you want to make a lot and you don't have an enormous one. The smaller ones are easier to lift. But then you are using two burners, and you have doubled your clean-up.
Add the herb bouquet. Again, this has a million variations. The one I think is best is this. You take the green part of a leek. Spread it out like parchment paper. Add several sprigs of parsley, some thyme, some bay leaves, some garlic cloves, some black peppercorns, and two whole cloves. GO EASY on the whole cloves. They give the stock a nice spicy accent, but they are powerful. If you use more than that, they will take over. Wrap all that stuff in the leak leaf, and tie it up with twine. If you don't have a leek, you can use one of those little cotton-mesh herb bouquet bags. If you don't have one of those, just tie the stuff together on its own. Last resort, dump it all in. Oh, and for this I would definitely get fresh herbs -- at least the parsley, thyme and bay leaves. And, if you really want to got nuts, add a pig's foot. The gelatin is good for the stock.
Turn up the heat, and stick around. It will take a long time to warm up that much liquid. You DO NOT want the pot to boil. As you see progress, turn the heat down in increments. After 45 minutes to an hour (depending on stove power and pot size) the burner should be down to low, and you should see the slightest motion at the surface. Let it simmer like that, partially covered, for five hours. You can let it simmer longer, I personally doubt that it adds much. But from experience, I can say that five hours is better than four. Skim scum off the top periodically. Take care not to remove too much of the good stuff, some of which also floats to the surface. Still, it's best to remove as much scum as you can, as it adversely affects both the flavor and clarity of the stock.
When your five hours are up, move the pot to another burner (a cool one) or a trivet. Let it cool for a while. Time to strain. First, using tongs or a slotted spoon, remove the largest pieces of meat and bone and discard. (Or save for the dog.) Now, for what comes next, I use first a China cap, then a chinois. Not everyone is going to have these. But they are useful. The China cap is a conical strainer with small holes. It separates the liquid from largish pieces. Do that first. The chinois is a fine mesh conical strainer. Do that second. If you have a good chinois, it will catch A LOT of crap. In fact, you will have to pause and clean the pasty gunk out of it from time to time. This is a pain, but it is very good for your stock. Those particles are not helpful. They don't taste good, and they can burn when you use the stock. I read an interview once with Thomas Keller in which he said that never moves liquid from one container to another without straining it. When making demi-glace, that is good advice.
When the liquid is completely strained, let it cool to room temperature. Then put it in the fridge. (If you put it in the fridge while still hot, you can seriously screw up your fridge. They are just not built to have to cool such a huge volume of hot liquid.)
The next morning, there will be a sheet of semi-solid fat at the top of the stock. It will look like an ice rink. This is good. It makes all that fat very easy to remove. Remove it, as thoroughly as you can. Fat adds nothing to finished stock. Strain it again, through the chinois.
Now, if you want a traditional demi-glace, the next thing to do is to make an espagnole sauce. This has fallen out of favor, primarily because it is roux-based, and modern chefs do not like roux-based sauces. The knock against them is, roux is a cheat, you can taste the flour, and if it does not bind properly, your sauce will separate. All true. However, done well, I think it works. To be done well takes time.
However, you don't have to do this. You can take your stock and reduce it to a glace de viand. Simply put it on the stove, heat it up, and reduce using a medium simmer to any consistency you desire. Skim often. Reduce long enough, and it will thicken naturally, becoming a syrup. This has its uses. I honestly think the real demi-glace makes a better sauce, but you may not.
Anyway, to make the real thing, we need a brown roux. This is a one-to-one mixture of butter and flour. It is best to clarify the butter. That is, melt it, and then spoon out the milky solids. Use only the clear yellow liquid. The solids will burn, and a burned roux is a disaster for your sauce. How much roux you need depends on how much sauce you want to make. Let's presume you want a lot, and will use four quarts of stock. Then melt two sticks of butter, and clarify. That should yield around 12 tablespoons. Add 3/4 cup of flour. Mix together over medium heat. Cook until the butter and flour congeal into paste and turn a deep nut brown -- say, like EG chestnut. Burnt Pine is too light. You must stir it constantly; there is no way around this. If the roux is not constantly moving, it will burn. The cooking time will be at least a half hour. Be very careful not to let the roux burn. When it is nice and pasty, and the right color, set aside.
Once again, you need chopped carrots, onion, and celery. This time, chopped very fine. Don't use a food processor. It just liquefies the vegetables. Take the time to chop them by hand. Once again, half as much celery as the other two. Say, two cups each onion and carrots, one of celery. You can scale down the carrots, but not the onions.
You have to cook the vegetables to caramelize them. You can do this with butter, oil, or bacon fat. The latter has the best flavor, I think. Some recipes also call for a small amount of boiled ham, chopped up, to be cooked with the veggies. You can also add pureed tomatoes at this stage. The alternative is to add tomato paste when you dump the veggies into the liquid. Unlike with stock, for espagnole, this step is NOT optional. Tomatoes are vital to the sauce's flavor. Anyway, use a half a cup of pure, or 8 tablespoons of paste. Or half and half (my preference, because the sugar in the paste adds sweetness).
Meanwhile, the stock should be heated in a separate pot and the roux whisked in. When they are blended, and the veggies are all cooked, dump them in. Add a bouquet garni, same as before. Up heat until you get a simmer, then lower it. Skim up scum. About three hours is enough for this stage, certainly no more, and maybe less.
Strain as obsessively as before. Repeat the overnight in the fridge step, and the de-fatting step. You now have espagnole sauce. This is quite a good sauce in its own right. If you want, you can even reduce it some, though it should be plenty thick at this stage, thanks to the roux.
In any event, it is not demi-glace. As you might have guessed from the name, demi-glace is ... half glace. That is, half stock, half espagnole, reduced. The flavor is deeper, more complex, and more intense than either is by itself.
Presumably, if you are going to make demi-glace, you won't want any leftover espagnole. It serves the same purpose, and demi-glace is better. So measure how much espagnole you have, and combine all of it with an identical amount of stock. Strain them both as you pour them into a pot. Throw in another herb bouquet, and reduce by half. Again you can reduce more if you want. You just end up with less. There is a point of diminishing returns, however. Sauce is always thicker when cooler. It should be served at a very low simmer temperature. If it is thick at that temp, its consistency is good. The heat at which you reduce it will be higher and the sauce will have a more liquid consistency. If it starts to appear thick at that temp, definitely stop reducing.
Another trick is to put the pot to one side of the burner. The heat concentrates in one area, and creates a convection effect that carries the scum to the other side. This makes skimming a lot easier.
When done reducing, strain again. You can do the fridge thing once more, but in all likelihood, there won't be any fat left to skim if you have done a good job before. Parcel it out into containers you find convenient, and freeze. Six months is supposed to be the upper limit of how long this will keep. I have gone at least nine, and not noticed a problem.