Roux is a smooth blend of flour...

Roux is a smooth blend of flour and fat cooked together. It adds body and flavor to soups, sauces and gravies.

There are three types: white (roux blanc), used for white sauces; tan (roux blond), used for light-colored sauces; and brown (roux brun), used to add flavor and color as well as thickening.

All three are made from equal quantities of flour and fat. The only difference is how long they are cooked.

To make any roux you need a heavy skillet or saucepan. Heat the fat--butter, margarine or oil--over medium-low heat and melt it carefully, watching to be sure it doesn’t brown or burn.

Next, whisk or stir the flour into the fat. I prefer using a wire whisk, but if you choose a spoon, use one made of wood. A metal spoon may become too hot to hold (a metal whisk handle rarely gets hot) and and plastic can melt in the hot fat. I find the whisking easier if the pan is removed from the heat until the mixture is completely smooth.

When the fat and flour are combined, continue to stir the mixture constantly over medium-low heat to distribute the heat so the starch granules in the flour swell evenly. If this isn’t done correctly, the granules will not be able to absorb the liquid you’re going to add later, and the sauce will turn out too thin.

It’s important not to hurry this cooking period. Too much heat will burn the flour and produce a bitter taste. It will also shrink the starch granules.

White and blond roux are made quite quickly, but brown roux takes a little patience. The mixture must be cooked, stirring constantly to prevent it from scorching or burning, for up to half an hour.

Roux can be used immediately or stored in the refrigerator for up to a week. It may also be frozen by dropping tablespoonfuls onto a baking sheet that is placed in the freezer. When they are frozen, transfer the roux wafers to a plastic freezer bag. To use, drop them into a sauce or soften in a double boiler over hot water, then continue as the recipe directs.

For soups, use a roux made with 1 tablespoon fat and 1 tablespoon flour for each cup of liquid.

For sauces, use a roux made with 2 tablespoons fat and 2 tablespoons flour for each cup of liquid.

Thicker mixtures are also made from 3 tablespoons fat and 3 tablespoons flour per cup of liquid. They are primarily used for bases for souffles.