What is a roux primarily used for?

• A. Emulsifying
• B. Sweetening
• C. Thickening sauces
• D. Leavening

Answer: (C)

Roux is a fat-and-flour mixture used to thicken sauces, gravies, and soups. The fat coats the flour so it doesn’t lump, and when you whisk in liquid, the flour’s starch granules swell and gelatinize, creating a smooth, viscous body in the sauce. You can cook roux to different colors—white, blond, or brown—which changes flavor and appearance, but the job of thickening stays the same. In many classic sauces like béchamel and velouté, roux provides the structure and creamy texture that holds the sauce together. It’s not for sweetening or leavening, and while it can help with a stable emulsion to some extent, its primary function is thickening.