Roux is a mixture of cooked flour and fat for thickening sauces, stews, and soups. It’s an essential part of European culinary tradition, as well as Cajun and Creole cuisine, and many others. There are four general types of roux: white, blonde, brown or brick, and dark. The type of roux depends on what you’re cooking and typically is deeply tied to that cuisine. It’s also important to note that the darker the roux, the less thickening power it has because the longer flour cooks, the more its starch breaks down.
Cooking the flour changes its taste and brings out a nutty flavor. Just how much depends on which roux you’re making. While a white roux is cooked just enough to remove the raw cereal flavor of the flour, a dark roux on the opposite end of the spectrum is cooked long enough to give it a deep color and extra toasty flavor.
Though roux is almost always made with all-purpose flour, the fat used can vary. Butter (whole or clarified) is typically the fat of choice, but oils and rendered fats are also commonly used. It’s very important
How to make roux:
60% flour – 40% fat (by weight)
In a saucepan, heat fat over medium heat and whisk in flour. Constantly whisk until you reach the desired color. The roux should be smooth, moist, and glossy (almost like wet sand). If it becomes too dry or greasy, add more fat or flour in small increments to adjust the texture.
If making a darker roux and/or larger quantities, you may put it into a 350º oven to finish cooking. Just make sure to check in and stir it periodically.
A good rule when using roux is to make sure both it and the liquid to which you’re adding are both warm. Doing so will aid incorporation and reduce clumping. In general, avoiding temperature extremes between the two (as with many techniques) is best. Now go out and thicken some sauces!
