What ingredient is primarily used to thicken sauces in classical cuisine?

Roux is a fundamental thickening agent in classical cuisine, consisting of equal parts of flour and fat, typically butter, that are cooked together. This technique is essential in creating a smooth and stable base for many classic sauces, such as béchamel, velouté, and even gravies. When cooked, the flour in the roux undergoes a transformation, which allows it to effectively trap liquid and thicken sauces while providing a rich, buttery flavor.

The preparation and cooking time of the roux can vary depending on the desired color and flavor; for example, a light roux is used for white sauces, while a darker roux is used in dishes like gumbo, adding depth to the final product. Understanding the role of roux is crucial for mastering classical sauce-making techniques, making it a cornerstone of culinary training.

Other options, while they are used for thickening, do not have the same versatility or traditional grounding in classical sauces as roux. Cornstarch, for instance, is often used for quick thickening in various cuisines but does not provide the same flavor complexity. Flour can be used directly to thicken, but it is less effective than roux because it may clump or produce a grainy texture if