Here's a recent post that I did on roux. A beurre manie can basically be thought of as an uncooked roux, and therefore be used in the same ratios as a roux. The only exception is substituting it out for a brown roux, which has about 1/3 of the thickening power of the other two rouxs.
Hope this helps. I would've just posted a link to this article but I'm still a new member and they won't let me link out in my posts yet.Guidelines for Roux
- Don’t use margarine or shortening. Yes they’re cheap, but margarine tastes horrible and shortening adds no flavor; not to mention it can give you a bit of a fuzzy mouth feel.
- Use clarified butter, oil or animal fat.
- Don’t use whole butter. Whole butter is about 15% water and will give you a less consistent product than a roux made with pure fat.
- A good roux is paste like and is not runny or pourable. A roux that has too much fat and is too runny is called a slack roux. Excessive fat in your roux will be released into your sauce, making it greasy and forcing you to spend extra time skimming and de-fating your sauce.
- Cake flour has about 20% more thickening power than bread or AP (All Purpose) flour. However, since bread and AP flower are more common than cake flour, most recipes that call for a roux assume that you will be using AP flour.
The process for making roux is extremely simple. Just place equal parts of flower and fat, (traditionally clarified butter), in a sauce pan and cook over medium heat. How long do you cook it for? Well that depends on what kind of roux you wish to make.
There are basically three types of roux which are differentiated by the degree to which the roux is cooked.
White roux is really more of a yellow roux that you basically cook for just a few minutes until the fat and flour are evenly mixed together and start to froth. You want to cook out the raw taste of the flour, but stop cooking the roux before it starts to turn color. White rouxs are used for white sauces that are cream and milk based such as bechamel and alfredo.Blond Roux
Blond roux is cooked a little longer than your white roux, just until it starts to slightly turn color. Blond roux is used for white sauces that are stock based, such as veloutes.Brown Roux
Brown roux is traditionally used for brown sauces, which are sauces based upon brown roasted stocks such as the mother sauce Espagnole. The key to a good brown roux is to cook it over low heat so that it browns evenly without scorching. Some chefs will even dry roast their flower in the oven first before making it into roux.
A good brown roux will have a rich and nutty aroma, and is great for thickening brown sauces and gravies. Just remember that a dark brown roux will have about a third of the thickening power of a blond or white roux.Incorporating Roux Into a Sauce or Soup
Roux can be added to a sauce either warm or cold, but never hot. A sizzling hot roux will separate and break when it hits a cold sauce, causing lumps and the loss of the roux’s thickening power.
Once the roux is added into the liquid you wish to thicken, whisk vigorously to incorporate and bring sauce to a simmer. Most roux thickened sauces are simmered for at least 20 minutes to cook out any starchy taste created by the flour. During this simmering, it is a perfect time to skim off any scum or fat that rises to the top.Now what kind of ratio and proportions should you use when thickening with a roux? It’s as easy as 3,4,5 & 6.
3 ounces of roux per quart of liquid will thicken a sauce to a thin or light consistency.
4 ounces of roux per quart = medium body sauce.
5 ounces of roux per quart = thick sauce.
6 ounces of roux per quart = heavy gravy.