More than any recipe or expensive ingredients, there's one basic skill you can learn in the kitchen that will transform your cooking: how to make a roux. Maybe you've heard of roux (pronounced "roo") and wondered what all the fuss was. It's something French chefs use, or it's only necessary for Creole and Cajun cooking, right? Yes, roux is good for fancy sauces and gumbo, but you can also use it as a thickener in home-cooked mac and cheese, green bean casserole, and sausage gravy.
This simple cooked mixture of flour and oil makes an almost paste-like substance that is used to thicken sauces, soups, gravy, and basically anything that you want to have a smooth texture and rich taste. It's simple to make; all you do is cook flour and fat together over low heat. And yes, you can make it in batches ahead of time so it's ready to go in an instant for a weeknight dinner.
Here's everything you need to know about making roux.
What is roux made of?
Roux is made from equal parts of flour and fat. You can use any kind of oil or animal fat, depending on the choice, dietary preferences, allergies. Whether you measure your ingredients by volume or by weight, use a 1 to 1 ratio (e.g. one teaspoon butter and one teaspoon flour, two ounces of lard and two ounces of flour, etc).
You can use whole wheat flour instead of all-purpose flour. You may notice a slightly different taste, but if you often cook with whole wheat flour (or if, like me, you start cooking without checking what ingredients you actually have on hand) it works in your recipes just as well. I haven't tried using gluten-free flour in a roux, but I have seen rice flour mentioned as a good substitute to make a gluten-free roux.
What Are The Steps to Make a Roux Sauce?
1. Place your choice of fat in a heavy bottom skillet, dutch oven, or other pan over low to medium-low heat.
2. Add an equal amount of flour.
3. Whisk or stir with a wooden spoon until smooth. Keep whisking until the roux is the desired color.
How to Make a Dark Roux
Cooking time depends on what kind of roux your recipe needs. There are four types of roux: white, blond, brown, and dark brown. The darker the roux, the longer it cooks. The two lighter rouxs are used primarily as a thickening agent for things like béchamel (a creamy white sauce), since the longer a roux cooks, the less thickening power it has. With those rouxs, you mostly want to make sure the flour is fully cooked because raw flour tastes terrible. White roux cooks for 2-5 minutes, while blond roux cooks for up to 10 minutes. Once the roux starts to smell nutty, you know the flour is no longer raw.
The longer you cook a roux, the more of a nutty flavor it has. Brown and dark brown roux is going to take at least 30 minutes, and you're probably going to need closer to an hour or more for a darker roux.
Do I really have to whisk the entire time?
The answer depends on how much of a risk taker you are. On the safe side, yes, you really do. You know what happens to butter or oil when you put it in a skillet and have the heat just a bit too high? Or don't get your other food in the pan fast enough? It's not pretty. The same goes here. If black flecks show up in your fat and flour mix, you might as well toss it and start over, otherwise, your entire dish will taste bitter and burnt. Think of making a roux as an opportunity to practice mindfulness, or being present in the moment. But if you do chance it and step away from the stove, keep it quick and keep one eye on your skillet.
Can you made roux ahead of time and freeze it?
Yes, you can make a batch of roux and put it in the freezer. It keeps for up to six months. A great way to store it is freeze it in ice cube trays then place those cubes into a plastic freezer bag.
Is there an easier way to make a roux for recipes like gumbo, gravy, and cheese sauce?
If you're making a white or blond roux, the stove top is your best bet. If you're making a dark roux and not interested in stirring it for an hour, you can put the flour and fat into a cast iron skillet or dutch oven and bake it in a 350-degree oven for about two hours. Keep an eye on it and stir it every 20 minutes or so.