Nomora Food

How to Make a Roux

Learn the simple flour-to-fat ratios, heat levels, and color stages for roux. Plus: how to prevent lumps, when to add liquid, and which soups and sauces use each roux.

Recipe by Maya Lin

Roux is one of those quiet kitchen skills that makes everything feel more restaurant-quality without adding stress. It is simply flour cooked in fat, and it thickens soups and sauces with a silky body you cannot quite fake with cornstarch alone. Once you understand ratios and heat, you can make it on autopilot on a Tuesday night.

Butter melting in a small saucepan with flour and a whisk nearby on a home kitchen counter

What roux does

Roux thickens because flour contains starch. When you cook flour in fat first, you coat the starch granules and toast off raw flour taste. When you later add liquid and bring it to a simmer, those starches hydrate and swell, creating a smooth thickened sauce or soup base.

Two practical takeaways:

More cooking time means less thickening power. A darker roux tastes deeper and nuttier, but it thickens a bit less than a pale roux.
Heat control matters more than speed. A rushed roux is how you get scorching, clumps, and that “why does this taste like burnt popcorn?” moment.

Roux ratio and amounts

Classic ratio

The standard roux is equal parts fat and flour by weight. For home cooking, measuring by volume works well too: 1 tablespoon fat + 1 tablespoon flour makes a small roux.

A useful starting point

Thickness depends on your flour, your liquid, and how long you simmer, so treat this as a starting point and adjust.

Light to medium thickness: about 1 tablespoon butter (or other fat) + 1 tablespoon flour per 1 cup liquid
Thicker, gravy-like: about 1 1/2 tablespoons fat + 1 1/2 tablespoons flour per 1 cup liquid

For a typical weeknight pot of soup, I often start with 3 tablespoons butter + 3 tablespoons flour, then add about 3 cups broth or milk and see where it lands.

Two measuring tablespoons on a cutting board, one filled with flour and one with softened butter

Choosing your fat

You have options, and each one nudges the flavor a little.

Butter: Classic for béchamel, mac and cheese, creamy soups. Rich flavor. Watch heat so the milk solids do not burn.
Neutral oil (canola, avocado): Great for higher heat and longer cooking, especially for brown roux.
Animal fat (bacon drippings, chicken fat, duck fat): Adds savory depth to chowders, gravies, and hearty soups. Strain first if it has browned bits that may burn.

Heat level

Most roux problems come from heat that is too high. Aim for medium-low to medium heat until you know your stove.

White roux: medium-low is plenty
Blond roux: medium, adjusting down as needed
Brown roux: medium to medium-low, and be patient

Use a heavy-bottomed saucepan or Dutch oven. Thin pans create hot spots, which is a fancy way of saying “burnt in one corner.”

A wooden spoon stirring a smooth roux in a stainless steel saucepan on a stovetop

How to make roux

Melt (or heat) the fat. Add butter or oil to your pan over medium-low heat. If using butter, let it fully melt and wait until the foaming subsides.
Whisk in flour. Sprinkle flour in while whisking. You want a smooth paste with no dry pockets.
Cook, stirring often. Switch between a whisk and a flat-edged wooden spoon or silicone spatula. Scrape corners and the bottom of the pan.
Stop at your target color. White, blond, or brown, then move directly into adding your liquid (details below).

Sensory cue: A roux should look glossy and cohesive, like wet sand turning into a smooth paste. If it looks greasy with separated oil pooling, your heat may be too high or your ratio is off (easy fix below).

Roux colors

Think of roux color like toast. Pale is mild and thickening. Dark is nutty and complex, with slightly less thickening power.

White roux

Time: about 1 to 3 minutes

Look: pale, bubbly paste, no browning

Flavor: neutral, no raw flour taste

Best for: creamy sauces and lighter soups where you do not want toasted flavor.

Béchamel (white sauce)
Cheese sauce for mac and cheese
Cream of mushroom or cream of chicken soup
Turkey gravy when you want a lighter color

Blond roux

Time: about 3 to 6 minutes

Look: light golden, like blonde peanut butter

Flavor: gently nutty, warmer than white

Best for: gravies and soups that benefit from a little toastiness but still need good thickening.

Chicken gravy
Sausage gravy
Pot pie filling
Many chowders (corn chowder, potato chowder)

Brown roux

Time: about 10 to 25 minutes, depending on heat and pan

Look: deep caramel to milk-chocolate brown

Flavor: distinctly nutty, toasted, almost coffee-like

Best for: bold, savory dishes where roux flavor is part of the point.

Gumbo
Étouffée
Deeply flavored stews and gravies

A pale white roux being whisked in a small saucepan, smooth and bubbling lightly

A light golden blond roux in a saucepan, thick and glossy as it is stirred

A dark brown roux in a Dutch oven being stirred with a wooden spoon, caramel colored and glossy

Adding liquid

The smoothest sauces happen when you add liquid gradually and whisk like you mean it.

How to avoid lumps

Keep the roux hot, not smoking. Medium heat is usually right.
Add a splash of liquid first. Start with a few tablespoons, whisking constantly. It will seize into a thick paste at first. That is normal.
Keep adding in small pours. Whisk smooth after each addition before adding more.
Bring to a gentle simmer. Roux thickens as it reaches a simmer, then continues to tighten a bit over the next few minutes.

Cold vs warm liquid: You can use either. Warm liquid can feel a little easier, but the real key is adding it slowly while whisking thoroughly.

Hands whisking while a small stream of milk is poured into a roux in a saucepan

Simmer and season

Once your sauce or soup base hits a gentle simmer, give it at least a few minutes (often 2 to 5) to fully thicken and cook off any lingering flour taste. For thicker sauces like gravy or cheese sauce, a few extra minutes at a low bubble can make the texture noticeably silkier.

Roux itself is not seasoned. Salt and pepper are best adjusted after the sauce has simmered, when the final thickness and flavor are settled.

Fixing lumps

Lumps happen. They are fixable almost every time.

Fix 1: Whisk off the heat

If you see lumps forming as you add liquid, pull the pan off the burner and whisk vigorously for 20 to 30 seconds. Taking away heat gives you a calmer window to smooth things out.

Fix 2: Add a little more liquid

Sometimes lumps are simply “too thick too soon.” Add a splash of liquid and whisk again. Thinner gives the whisk room to work.

Fix 3: Strain or blend

If the sauce is already hot and you cannot whisk out the lumps:

Strain through a fine-mesh sieve into a clean pot, pressing gently.
Blend with an immersion blender for 10 to 20 seconds (great for soups).

Common causes

Dumping in liquid all at once
Not whisking into the corners of the pan
Roux not fully mixed before cooking (dry flour pockets)

Greasy or broken roux

If oil is pooling and the roux looks separated, your ratio may be heavy on fat or your heat is too high.

Turn the heat down. Give it 30 seconds to calm.
Whisk in a little more flour. Start with 1 teaspoon at a time until it looks like a cohesive paste again.
Keep stirring. A roux likes attention, especially as it gets darker.