What is Roux?

Roux (pronounced rue) is used as a thickening agent for soups and sauces. It is made up of equal parts flour and fat. Clarified butter is usually the fat of choice. You can use margarine, oil or rendered fat from meat. The flour and fat are cooked together in a pan over medium/low heat stirring continuously. Melt the fat and stir in the flour. It is best to use a wooden spoon. Referring to the color, there are basically three stages of roux with varying shades in between.

They are:

White- The mixture is cooked only long enough to lose the raw flavor of the flour without imparting any color. It will be a little gritty in texture. It is used for white sauces and soups, like béchamel or New England chowder.

Blonde- This roux is cooked a little longer as to pick up a blondish color (go figure). It will be a little smoother than a white roux. It is used to thicken pale colored sauces, soups and gravies, like chicken gravy.

Brown- This roux is cooked longer, so it develops a deep brown color and nutty flavor. If you burn it, throw it out and start over. A brown roux is used to thicken sauces such as espagnole or brown gravies. It is important to note that the darker the roux, the less thickening power it will have. A brown roux will be about 2/3 less potent than a white roux.

A roux can be made ahead of time and stored in the refrigerator up to a month. In some instances it can be made right in the pan you are making your sauce or soup in. I like to do this with white gravy for biscuits, with the rendered fat from the sausage. New England clam chowder is traditionally started with salt pork or bacon, so you can make your roux from that rendered fat as well.

To thicken a sauce or soup with a pre made roux, add roux a little at a time. To prevent lumping, make sure that your liquid is very hot and use a wire whisk to incorporate. Remember, your roux will not reach its’ full thickening potential until the sauce/soup comes up to a boil.

When adding liquid to roux, you don’t want the liquid to be excessively hot, or it may not homogenize properly and will be lumpy.