roux

A roux (from the French roux, meaning "red" or "russet") is a cooked mixture of equal parts fat and flour by weight, used as a thickening agent in cooking. The fat—typically butter, lard, or oil—is melted and combined with flour, then cooked over heat for varying durations depending on the desired color and application. The cooking process allows the starch granules in the flour to swell and gelatinize, creating a thickening mechanism when the roux is combined with liquids. Roux is classified by color: white or pale roux (cooked briefly, 1-2 minutes), blonde or light roux (cooked 3-5 minutes), brown roux (cooked 5-10 minutes), and dark brown or espagnole roux (cooked 10+ minutes). As the roux darkens, its thickening power decreases but its flavor becomes more complex and nutty.

Roux is fundamental to classical French cuisine and is a building block for many sauces and gravies. It is also central to Creole and Cajun cooking, particularly in Louisiana, where dark brown roux is standard for gumbo and other traditional preparations.

Roux functions primarily as a thickening agent and flavor base in soups, sauces, stews, and gravies across numerous culinary traditions. In French cuisine, roux forms the foundation of mother sauces: béchamel (white roux with milk), velouté (blonde roux with stock), and espagnole (brown roux with brown stock). Cajun and Creole cooking employs dark roux extensively, particularly in gumbo, where it develops deep, savory notes and acts as both thickener and flavor component. The choice of roux color determines the final sauce's depth and character. Roux is prepared by whisking fat and flour together over moderate heat, then combined with liquid in a gradual stream while stirring to prevent lumps. It can be made ahead and stored, making it a practical mise en place component for professional and home kitchens.