A roux—pronounced “roo”—is a cooked mixture of flour and fat.
That description sounds almost too simple for something so important to Louisiana cooking. But flour cooked with oil, butter, lard, drippings, or another fat can thicken a sauce, change its color, remove the flour’s raw taste, and develop increasingly toasted flavors as it cooks.
In Louisiana, roux is especially associated with gumbo, étouffée, gravies, soups, and sauces.
Two ingredients.
A lot of responsibility.
What Is Roux Made From?
Traditional roux needs two basic ingredients:
Flour and fat.
All-purpose wheat flour is common. The fat can be butter, vegetable oil, lard, animal drippings, or another cooking fat suited to the dish.
Classical culinary instruction traditionally describes roux as equal parts flour and fat by weight, although actual recipes vary. Louisiana home recipes commonly use simple measurements such as one cup flour and one cup oil. Explore Louisiana uses exactly that formula for its traditional roux demonstration.
The goal is not simply to mix flour into grease.
The mixture has to cook.
What Does Roux Do?
Roux can perform three major jobs:
It thickens. It adds flavor. It adds color.
When liquid is added, starch in the flour helps give body to soups, sauces, gravies, and stews. Cooking the flour beforehand also removes its raw cereal taste and, as the roux browns, creates increasingly toasted and nutty flavors.
A pale roux is used mainly for thickening.
A deeply browned Louisiana roux can become one of the principal flavors in the dish.
That difference is why “make a roux” is only half the instruction.
The next question is:
What kind?
Roux Has French Roots
Roux is not a Louisiana invention.
It is an old French culinary technique used to thicken sauces, soups, and stews. Classical French cooking traditionally uses pale, blond, and brown roux in different preparations.
Louisiana inherited that technique through its French culinary heritage but developed distinctive ways of using it.
Most notably, Cajun and Creole cooks often take roux much darker than the pale versions associated with cream sauces and many classical French preparations. Culinary Institute of America materials specifically note the importance of dark roux in Cajun and Creole cooking, where it gives gumbo and stews their distinctive toasted character.
Louisiana did not invent flour and fat.
It gave them a much longer shift at the stove.
Roux Was Documented in Early Louisiana Cookbooks
Louisiana’s roux tradition is not merely a modern Cajun restaurant development.
The 1884 Creole Cookery Book published in New Orleans gives separate instructions for both brown roux and white roux. Its brown version combines butter with flour and cooks the mixture carefully until it develops a yellowish-brown color, while its white roux is deliberately prevented from browning.
That historical recipe shows two things.
Creole cooks were using recognizable French roux techniques in nineteenth-century Louisiana, and they already understood that different colors produced different results.
The very dark roux strongly associated with modern Louisiana gumbo would become another important branch of that tradition.
What Color Is Roux?
Roux can range from almost white to deep chocolate brown.
Louisiana cooks commonly talk about stages such as white, blond, peanut-butter, medium-brown, and dark-brown roux. The longer flour cooks in fat, the darker it becomes and the more toasted flavor it develops.
Color is not merely cosmetic.
It tells you something about both flavor and thickening ability.
Article 347 will look closely at the different colors of roux.
For now, the important idea is simple:
Cooking time changes what the roux does.
Darker Roux Has More Flavor but Less Thickening Power
This is one of the most useful things to understand about roux.
As flour browns, its flavor becomes deeper and nuttier—but some of its ability to thicken liquid decreases. Explore Louisiana specifically notes that longer cooking creates darker, more flavorful roux while reducing thickening power. Professional culinary references make the same point about heavily browned flour.
That is why a dark gumbo roux should not be thought of merely as a stronger version of a white roux.
It is performing a somewhat different job.
The pale roux emphasizes thickening.
The dark roux contributes substantial flavor and color along with some thickening.
Why Is Roux So Important in Gumbo?
Gumbo and roux are closely connected in modern Louisiana cooking.
64 Parishes describes roux—a simmered mixture of fat and flour—as the base of most Louisiana gumbos. Explore Louisiana similarly identifies roux as a typical foundation for the dish, alongside the holy trinity and other possible thickeners such as okra or filé.
A dark roux gives gumbo its characteristic roasted depth and can also contribute much of its brown color.
Once the roux reaches the desired stage, Louisiana cooks commonly add onion, celery, bell pepper, stock, meat, seafood, seasonings, or other ingredients depending on the recipe.
The roux is therefore not something sprinkled into gumbo at the end.
It often helps build the entire pot.
Does Every Gumbo Have Roux?
No.
This is where Louisiana food resists an easy rule.
Roux is extremely common in modern gumbo, particularly many poultry-and-sausage and seafood versions, but Louisiana gumbo has always varied by place, period, community, and cook. 64 Parishes documents gumbo traditions using okra, filé, roux, or combinations of thickeners, and even contemporary Louisiana cooks who make gumbo without roux.
Historical gumbo recipes also show considerable variation.
So roux is central to much of modern Louisiana gumbo.
It is not a requirement for every gumbo ever cooked in the state.
Roux and Étouffée
Roux also appears frequently in crawfish and shrimp étouffée.
The roux is usually much lighter than the deeply browned version favored in many gumbos. That allows it to provide more thickening while keeping the sauce lighter in color and letting crawfish or shrimp remain the main flavor.
Explore Louisiana describes roux as a foundation for both gumbo and étouffée.
But étouffée varies too.
Some family and regional versions use very little flour or thicken primarily through the cooking process itself.
Louisiana cooking does not become less Louisiana because two grandmothers disagree about flour.
Roux in Gravies and Sauces
Roux has plenty of work beyond gumbo and étouffée.
It can thicken meat gravies, cream sauces, seafood sauces, soups, and stews. Historical Creole cookbooks used roux for sauces long before gumbo became the dish most Americans associated with it. The 1884 Creole Cookery Book, for example, directs cooks to thicken a meat-based sauce with brown roux.
This broader use reflects roux’s French heritage.
Louisiana may be famous for dark gumbo roux.
But roux itself is a general cooking technique.
Oil or Butter?
Both can make roux.
Butter is traditional in classical French sauces and remains useful for lighter roux because it adds rich dairy flavor.
Louisiana dark roux is often made with vegetable oil or another fat capable of tolerating prolonged cooking. Explore Louisiana lists oil, butter, and lard among common roux fats, while Louisiana Cookin’ also notes vegetable oil, butter, and bacon drippings.
Animal fats can bring their own flavor too.
The best fat depends partly on what the roux is going to become.
Article 350 will compare oil roux and butter roux in more detail.
Why Cook Flour Instead of Just Mixing It with Liquid?
Raw flour can thicken liquid, but roux does more.
Cooking the flour in fat coats the starch, removes raw flour flavor, and allows the cook to develop toasted flavors before liquid enters the pan. The Culinary Institute of America notes that longer cooking progressively deepens both the flavor and color of the flour-and-fat mixture.
A roux therefore contributes something a simple flour slurry cannot.
Both can thicken.
Only one spent time browning in fat first.
Roux Is Not the Same as a Slurry
A slurry is usually starch—often cornstarch or flour—mixed with cold liquid and then added to a hot dish to thicken it.
Roux cooks flour in fat before the liquid is added.
That difference affects flavor, texture, color, and cooking technique.
A slurry can be useful when something needs quick thickening near the end.
A roux is often part of the structure of the dish from the beginning.
In gumbo, especially, the difference is enormous.
Why Does Roux Need Stirring?
Flour sitting against a hot pan can scorch.
Stirring keeps the flour moving through the fat and promotes even browning. Explore Louisiana recommends frequent to constant stirring and warns that a roux can burn if neglected. Louisiana Cookin’ similarly notes that dark stovetop roux requires close attention as it browns.
As the roux gets darker, the distance between beautifully toasted and burned becomes smaller.
Burned roux tastes bitter and generally has to be discarded.
Article 352 will deal specifically with why roux burns and how to prevent it.
Can Roux Be Made Somewhere Other Than the Stovetop?
Yes.
Stovetop roux may be the traditional image, but Louisiana cooks also use oven methods, microwave methods, prepared jarred roux, and dry-roasted flour. Louisiana Cookin’ documents stovetop, oven, and microwave techniques, while LSU AgCenter has published instructions for browned roux flour made without fat.
Those techniques do not all produce identical results.
But they demonstrate that Louisiana roux is a technique with several practical variations.
Upcoming EatBayou articles will examine stovetop, oven, and dry roux separately.
Is Jarred Roux “Real” Roux?
Yes.
Prepared roux is simply roux made in advance and packaged for later use.
Louisiana grocery stores have long carried commercial roux because it saves time and removes one of the most attention-intensive steps in making gumbo.
That does not make homemade roux unnecessary. Learning to make one teaches a cook how flour changes as it browns and provides direct control over fat, color, and flavor.
But dinner does not become counterfeit because the roux came from a jar.
Louisiana cooks are practical people.
Is Roux Cajun or Creole?
Both.
Roux has French culinary roots, and nineteenth-century New Orleans Creole cookbooks clearly document its use.
It also became fundamental to many Cajun preparations, particularly the dark roux associated with prairie and Acadiana-style gumbos. Modern Louisiana sources routinely identify roux as foundational in both Cajun and Creole cooking.
Trying to assign roux exclusively to one tradition ignores its much broader Louisiana history.
It is French in origin.
Louisiana made it its own in several different ways.
Roux at a Glance
| Roux | |
|---|---|
| Basic ingredients | Flour and fat |
| Pronunciation | “Roo” |
| Common fats | Oil, butter, lard, drippings |
| Main jobs | Thickening, flavor, color |
| Colors | White through deep brown |
| Darker roux | More toasted flavor, less thickening power |
| Major Louisiana use | Gumbo |
| Other uses | Étouffée, gravies, soups, sauces, stews |
| French roots? | Yes |
| Cajun or Creole? | Used in both |
| Must every gumbo contain it? | No |
| Can it be prepared ahead? | Yes |
The basic definition never becomes complicated:
Roux is flour cooked in fat.
Everything interesting happens after that.
Two Ingredients That Can Change an Entire Pot
Roux demonstrates something Louisiana cooking does particularly well.
It takes ordinary ingredients and makes technique matter.
Flour by itself is flour.
Oil by itself is oil.
Cook them together for a few minutes and they can thicken a sauce.
Cook them longer and they begin to smell toasted.
Keep going carefully and they can become the deep brown foundation beneath chicken, sausage, seafood, stock, vegetables, herbs, and spices in a pot of gumbo.
That is why Louisiana cooks talk so much about roux.
It is not complicated because of the ingredient list.
It is complicated because time, temperature, color, and judgment change what those two ingredients become.
And that brings us naturally to the next question:
What color should a roux be?
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