Food Word Friday: Roux

Some of the best sauces are those that are thick and lovely - think macaroni and cheese.  Probably the most common way of thickening sauce is by using a roux - and that is the food word of the day!

Roux refers to a combination of flour and fat (usually butter) that is used to thicken a sauce.  Flour and fat are traditionally used in equal amounts (by weight) - though you can experiment with the proportions.  I used a roux when making my souffle earlier this week - the base is essentially a bechamel sauce (milk sauce thickened with roux) to which cheese and egg yolks are added.  (Roux can be used to thicken almost any liquid - not just milk.  Think thickened chicken stock for making gravy.)

The basic approach to making a roux is as follows:

Melt the butter.

Whisk in the flour to form a smooth paste.

The roux can be cooked to varying degrees, depending on the type of flavor and color you want.  A white roux is barely cooked, while a blond roux is cooked slightly longer, and a brown roux is cooked until it is brown and has a nutty flavor and smell.  As the roux gets cooked more and more, it loses its thickening ability, so a greater quantity of brown roux is needed to produce an equal degree of thickening as compared to a white or blond roux.  The color/degree of cooking of the roux is largely determined by the desired color of the sauce it will thicken.

Once the roux is ready, the (to-be-thickened) liquid is whisked into the roux (along with any flavorings/spices, which can be seen in the picture).  Whisk very well to ensure you get rid of any lumps!

Cook, simmering, to allow the sauce to fully thicken and cook out the raw flour taste. 

The proportion of roux to liquid that you use depends on the thickeness desired in the final sauce.  In the example above, I used half a stick up butter and a quarter of a cup of flour to 1.5 cups of milk, and the result was on the thick end of how you would want to eat a sauce (it was going into a souffle, so it was a little bit different than eating a straight sauce).  If you are going to add things like cheese, that would thicken your sauce even more, so keep that in mind.

It takes just a little bit of practice to get used to working with roux, and especially with fall at hand, there will be plenty of dishes that would be lovely with a nice thickened sauce!