A roux is flour cooked in fat. It forms a base for thickening sauces, soups and gravies. The recipe determines how much roux to use and how dark to cook it; a pale sauce and a dark gumbo need different results.
What you need
- A saucepan, a whisk or wooden spoon, and the flour and fat measured for your recipe. Keep the cooking liquid ready before heating the roux.
Step by step
Heat the fat gently
Melt butter over moderate heat, or warm the specified oil. Add the flour and stir until no dry pockets remain. The mixture usually forms a thick paste, although its looseness depends on the recipe’s flour-to-fat ratio. It should remain easy enough to stir across the pan.
Image by JustRecipesCook to the colour the recipe needs
Stir continuously, reaching the base and corners. A pale roux loses its raw flour smell while staying light; further cooking gives progressively more toasted aroma and darker colour. Reduce the heat if parts darken faster than you can stir.
Whisk in the liquid gradually
For a straightforward sauce, lower the heat and whisk in a small amount of the recipe’s liquid until the mixture is smooth. Continue with small additions, loosening the paste each time before adding more.
Image by JustRecipesLet the sauce thicken
Bring the finished mixture to a gentle simmer while stirring. Judge thickness after it has heated through. Follow the recipe’s cooking time and final consistency rather than assuming the initial loose mixture has failed.
Lumps, scorching and unexpected thickness
Whisk vigorously if small lumps appear during liquid addition. A sieve can remove persistent lumps. Burnt flour needs a fresh start. A darker roux adds a different colour and toasted flavour. Follow the recipe’s intended stage rather than darkening every roux.
Handle hot roux carefully
Hot fat and flour can cause serious burns. Keep hands and face back when adding liquid, which can spit. Do not taste uncooked flour mixtures; judge the roux’s progress by its colour and aroma.
