Roux is a smooth paste, made from flour fried in fat.
Roux is typically made from equal parts of flour and fat by weight. The flour is added to the melted fat or oil on the stove top, blended until smooth, and cooked to the desired level of brownness.
Butter, bacon drippings or lard are commonly used fats.
The mixture is cooked by stirring over heat in a pot or pan. The fat is heated first, in the process melting it if necessary, then the flour is added, the mixture is stirred until the flour is incorporated and then cooked until at least the point where a raw flour taste is no longer apparent. The end result is a thickening and flavoring agent. The final results can range from the nearly white to dark brown, depending on the length of time it is over the heat, and its intended use.
• The white stage is reached once the flour loses its raw smell, after about 5 minutes of cooking and stirring
• The blond stage is reached after about 20 minutes of continuous cooking and stirring.
• The brown stage is reached after approximately 35 minutes of cooking and stirring.
• The dark brown stage is reached after about 45 minutes of cooking and stirring.
Light roux provides little flavor other than a characteristic richness to a dish, and is used in French cooking and some gravies or pastries throughout the world. Darker roux is made by browning the flour in oil for a longer time and adds a distinct nutty flavor to a dish.
It is the basis of three of the five mother sauces of classical French cooking: Sauce béchamel, Sauce velouté, and Sauce Espagnole.
It also provides the base for a dish, and other ingredients are added after the roux is complete.
Roux has been thickening savory dishes for centuries.
It has been used in Ottoman and Turkish cuisine since at least the 15th century.
As far back as 1651, François Pierre La Varenne wrote a cookbook in which he mentioned liaison de farine which was made with flour and lard. He called this mixture “thickening of flower,” and it later came to be known as farine frit, or roux.
As a subject of controversy, roux seems to have been under the radar until the 1970s, with the advent of “nouvelle cuisine.” Many people were watching fat (particularly saturated fat) and calories, and they felt that butter, lard, and flour did not belong in the kitchen or on the dinner plate. Then Paul Prudhomme exuberantly surfaced and brought a renewed interest in the roux with him. Roux, once again, appeared on the front burner of the food scene.
In Cajun cuisine, roux is made with bacon fat or oil instead of butter and cooked to a medium or dark brown color, which lends much richness of flavor, but makes it thinner.
Central European cuisine often uses lard or more recently vegetable oil instead of butter for the preparation of roux, which is called zápražka in Slovak, jíška in Czech, zasmażka in Polish, zaprška (запршка) in Bosnian, Serbian, and Macedonian, zapržak or ajnpren in Croatian, zaprazhka (запръжка) in Bulgarian, rántás in Hungarian, rântaș in Romanian and Mehlschwitze in German.
Staka (στάκα) is a type of roux particular to Cretan cuisine. It is prepared by cooking sheep’s milk cream over a low flame with wheat flour or starch: the protein-rich part of the butterfat coagulates with the flour or starch and forms the staka proper, which is served hot. It is generally eaten by dipping bread in it, occasionally served over French fries.
Japanese curry, or karē, is made from a roux made by frying yellow curry powder, butter or oil, and flour together. The French term roux has become a loanword in Japanese, rū, or more specifically karērū.
Water roux is a roux which bakers use to thicken doughs and allow the bread to become softer, fluffier, moister, and retain its fresh baked qualities for a longer period of time by giving the dough greater strength to retain much higher quantities of water than what would otherwise be achievable.