Help with making the perfect demiglace

[jasonr]

I want to make the absolute perfect demiglace, with no compromises. I don't care how long it takes or how expensive the ingredients are.

1. I have seen some cookbooks mention (in passing) that some chefs roast their flour before making the roux. But the books don't tell you how to go about doing this, or what modifications need to be made (if any) to the browning of the roux if you do this.

Can someone explain the purpose of doing this, and how exactly one does it? Does it allow you to produce a darker brown sauce, and therefore a darker final product? (demiglace) I would like to darken my demiglace, if only for aesthetic reasons. Are there any other advantages?

I have more or less the same question with respect to oiling the bones before browning. Does oiling the bones contribute to browning and make a deeper colour for the final product?

2. I've read that some chefs will use leeks in place of onions for the mirepoix. Are leeks superior to onions? Which part of the leek do you use, the green stalk or the white stem, or both? Do you use the exact same quantity?

3. What about bones? Up until now, I have been using big beef marrow soup bones, rib bones, and pretty much whatever they happen to have at the supermarket. Are there any specific bone types that are favoured above all others? Should I be seeking out some specific types?

4. What about salting? My natural instinct is to put very little (if any) salt in the stock / brown sauce / demiglace, and assume that 100% of the salting will take place at the final small sauce stage. But a chef friend of mine suggested that the salt helps bring out the flavor in the bones, and that the stock should be salted. Is there any truth to this? What is optimal for 6 litres of water?

[Andy M.]

Browning the flour just simplifies the process of making the roux. Making a roux the traditional way will give the same result.

Oiling the bones promotes browning.

Leeks, onions, little difference.

Include some veal bones as they contain much more colagen and will contribute to a more gelatonous product.

Salt at the end. Adding salt in the early stages is dangerous. When you reduce the liquid, you are concentrating the salt and could end up with a too salty product. Also, you may want more or less salt depending on what you are using the demi glace for. If you are using it in a saltier dish, a salty demi may be excessive.

[jasonr]

So Andy, just to be clear, is roasting the flour supposed to be a substitute for cooking the roux on the stovetop, or in addition to?

In general, is there a way to get a deeper colour to my demiglace? This latest batch was about a medium/light brown, but if I had my way, it would be as brown as molasses. Is there a way to achieve this effect?

What is the advantage of a more gelatinous stock? Does this improve flavour?

[Andy M.]

Roasting the flour is a substitute for cooking the roux on the stovetop. The stovetop cooking browns the flour, darkening the roux. Experienced roux makers reject the flour roasting method as not yielding a top notch roux. I have never tried it.

Roast dem bones to a rich dark brown.

It contribute to richness, flavor and texture. Something referred to as mouth feel.

[Chopstix]

Jasonr, here's a tip for richer, deeper-colored stock: Add a roasted medium-sized spanish (red) onion to your stock.

To roast onion over gas range, place whole unpeeled onion on a grill on very low fire. Turn the onion once in a while until uniformly black and charred and soft. About 30 minutes. Alternative is to place thick-bottomed skillet over very low fire. Peel whole onion, cut at equator and place halves cut side down on skillet. Roast for 30 minutes.

Another tip: When I make beef stock, I roast the bones with a little oil. No tomato paste. Also, for mirepoix I use onions, leeks, and carrots (which are also roasted before adding to the stock). This is based on Thomas Keller's recipe and I personally prefer it this way as I find that tomato paste and celery in classic stock recipes distract from the beef flavor.

TK adds just a little salt during boiling of the stock.

[jasonr]

Thanks Chopstix. I'm going to make some more demiglace this weekend, so I may try your approach. But I have one concern: won't charring the onions the way you suggest make the stock bitter?

[jasonr]

Ok, here's another question: right now, I am making my demiglace, freezing it in a ziplock bag, and using it for a later date. The idea is to make it in advance, and then I have it at my fingertips.

But does freezing hurt the quality of the finished sauce? Let's say I've invited to dinner the most gorgeous redhead I ever met with the greenest eyes and the biggest *AHEM*. Let's say someone really important is coming to dinner tommorrow and time is no object.

Do I use my frozen demiglace or do I take 16 hours to make it from scratch and make my sauce fresh?

What would a three star Michelin chef do?

[Andy M.]

I can't imagine a chef in any restaurant has the time to initiate a 16 hour process on a 'to order' basis. This is something that must be made ahead of time. I'm sure it can be frozen with no ill effects.

Ask the redhead if she has a sister.

[Jeff G.]

What a lot of people don't realize is there are many level of roux..

there is Blond, light brown, medium-light brown, medium brown/"peanut butter", and dark browns that range from the color of milk chocolate to the color of bittersweet chocolate. The dark roux's are very hard to get right but if you do the flavors are powerful. the hard part with the dark is NOT burning it. It's a good idea to add your flavor medley(onion, celery, bell pepper, etc) BEFORE the roux hits its color. It will continue to cook as long as the pan is hot. The medley will slow the cooking helping to prevent burning.

One thing about roux, the darker the LESS it will thicken a stock so you have to use more of it which of course brings more and more flavor!!!!

[jasonr]

Jeff, is brown roux supposed to be as brown as you are suggesting? Is making it this brown a technique that is supported by bona fide sources? Do you know how long a traditional chef would brown his roux (approximately), or how dark?

Also, will this have a dramatic effect on the colour of the final product? How do I go about cooking the roux to make it darker? Mine is nowhere near as dark as milk chocolate. At best, it's about the same colour as peanut butter. I cook it on low heat for exactly 10 minutes, which is what a chef friend of mine suggested.

When I brown it, the aroma changes somewhat, with a hint of nuttiness, and in the last two or three minutes, when you remove the whisk, it's hot enough to bubble.

It does not really darken at all, from start to finish, even though it's supposed to be a "brown roux". I was afraid to cook beyond the 10 minute mark, because it might burn, and I don't trust my sense of taste to be able to identify burnt roux (I have an incredibly poor sense of taste).

Should I just keep browning it on low heat until it gets to the desired colour? Is there a way to tell if it is burned that is objective (that doesn't require tasting it)?

I wish my books were better at explaining this. My Cordon Bleux Professional Cooking book doesn't give any kind of timeframe for browning, and it doesn't give you any idea of what "brown" is supposed to even look like! It's so frustrating.