A roux is the start of many great dishes. From a ridiculously good gumbo or the the beginnings of Béchamel sauce (essential to the perfect, creamy baked macaroni and cheese), the simple combination of equal parts fat (usually butter) and flour is a technique used to get the perfect consistency for soups and sauces. The standard ratio of fat to flour is 1:1, but you can adjust the consistency to get a moister mixture. On the flip side, you don’t want it so dry that it looks like sand. 

Roux is cooked to varying degrees depending on what you’re using it for. Here are the 4 types:

  1. White roux is cooked the least, maintaining the original white color of the flour.  
  2. Pale or blonde roux is cooked a little bit longer to acheive a light golden color with a toasty aroma.  
  3. Brown roux is a light brown color with a nuttier fragrance than blonde.
  4. Black roux should be a rich, dark brown color and have a strong roasted aroma.  

Here’s how to cook a roux:

  1. Melt your butter in a pan over moderate to low heat. Let it bubble.
  2. Add the flour and whisk until smooth.
  3. If necessary adjust the consistency with more flour. Roux should be glossy in appearance.
  4. Cook, whisk constantly, to the desired color. Use immediately or refrigerate until ready to use.

To combine your roux with a liquid, like milk or chicken stock, be sure the roux and the liquid are different temperatures. By combining hot roux and cool liquid or vice versa, you’ll prevent lumps. Combine them gradually and continually whisk until completely incorporated, then slowly bring to a simmer. Reduce your heat and cook for at least 20 minutes to be sure the flour is totally cooked.  

To thicken one gallon of liquid use 12 ounces of roux, but you can use up to a pound if you want it to be very thick.

*There is a such thing as a dry roux, which calls for you to toast the flour before using it. This type of roux is common in Creole and Cajun recipes.