How to Make Gluten-free Roux

Roux cooking in a saucepan with a wooden spoon.Roux (pronounced “roo”) is a thickening agent that chefs add to sauces, soups, and stews to give them a more pleasing texture. It is a staple of French cooking, though in the U.S. we typically associate it more with Cajun or Creole staples like gumbo.

Roux is made by cooking one part fat and one part flour together to form something resembling smooth gravy. White flour is a no-go when eating Primally, but never fear, you aren’t doomed to a lifetime of thin, runny étouffée, moussaka, and scalloped potatoes!

Today, I’ll show you how to make a traditional roux and how to swap in Primal-friendly ingredients for a gluten-free option.

How to Make a Roux (Traditional and Gluten-free Options)

For a basic roux that will thicken around 2 cups of liquid, you will need:


  • ¼ cup fat
  • ¼ cup flour


Heat your fat in a skillet or saucepan over medium heat. Once the fat is melted, slowly stir in your flour or starch while stirring. (See below for options)

Continue stirring and reduce the heat a little until a sauce forms. As you stir, the sauce will begin to thicken and eventually turn from white to tan to brown. A white or blonde roux takes about 1 to 3 minutes to cook, although this may vary slightly depending on the type of flour or starch you use. A dark brown roux can take 30 minutes or longer.

Continue cooking until the roux reaches your desired depth of color. After the roux is finished cooking to the color of your liking, remove the pan from the heat and allow it to cool for a bit before adding it to whatever dish you are using it for.

Important things to note:

  • A light colored roux is ideal for cream sauces or cheese sauces, like for mac and cheese. A darker tan or caramel colored roux will take longer to cook and is ideal for different types of hearty stews, soups, gravies, and gumbos.
  • A couple of tablespoons of roux can thicken up to 1 cup of liquid, but this will depend on the color of the roux. A dark-colored roux tends to thicken up dishes less than the white or blonde varieties. I find this to be especially so when using alternatives to flour like arrowroot or tapioca starch.
  • While the roux is cooking, you want it to be slightly bubbling but not boiling. Cooking the roux at too high of a temperature can often result in a gritty sauce at the end.

Roux FAQs

What ingredients can I use to make my roux gluten-free and Primal/paleo?

Flour is the go-to choice for making a roux, but there are many alternatives. Try a gluten-free flour blend, tapioca starch, arrowroot powder, or cornstarch. To keep it Primal/paleo, use tapioca or arrowroot starch. I find that starches like arrowroot and tapioca tend to perform better in light-colored roux.

There are many options for the fat in a roux, too. Ghee or clarified butter are the ideal choices. They have a nutty flavor, and the milk solids have been cooked out, which helps reduce the risk of burning. In lieu of ghee, you can use butter, animal fat like beef tallow, or even oil like avocado oil. Keep in mind that if you use oil, the roux will most likely separate if you store extra for later.

To thicken a sauce without fat at all, make a slurry by whisking together a few tablespoons of flour/starch and double or triple the amount of any type of milk (cow’s milk, nut milk, coconut milk, etc.). You can whisk this slurry into whatever dish you want to thicken.

How do you prevent your roux from forming lumps?

Take care to not heat the fat at too high of a temperature. Stir the flour into the fat a little at a time, and stir the roux frequently. This will help break down any little clumps of flour and also helps it cook evenly and not burn.

If you’d like, you can also use a flour sifter to sift the flour into the fat.

How can you tell if your roux is burnt, and what should you do if that happens?

You may notice your roux smelling a bit burnt or developing little black flecks in it. If this is the case, your best option is to toss the roux and start again, as the burnt flavor will permeate whatever dish you put it in.

What’s the best way to store a roux to use later, and how long will it last? How can you reheat it?

It’s never a bad idea to make a little extra roux, as it can always be stored for later! Pour the extra roux in an air-tight container and store in the refrigerator. You can keep it in the fridge for a few weeks, or freeze it for 3 to 6 months.

The easiest way to portion out roux for the freezer is to measure it out into ice cube trays, freeze the trays, and then pop the roux cubes into an airtight bag or container. Let the roux come to room temperature and give it a stir before adding it to a dish.

If you could offer one tip to a first-time roux maker, what would it be?

Cooking is all about experimenting and trying new things. If you’re not happy with your roux the first time, troubleshoot and try again! Experiment with cooking your roux for different lengths of time and using it in different dishes. You’ll quickly see how easy and versatile it is!

About the Author

Priscilla Chamessian

A food blogger, recipe developer, and personal chef based in Missouri, Priscilla specializes in low-carb, Paleo, gluten-free, keto, vegetarian, and low FODMAP cooking. See what she’s cooking on Priscilla Cooks, and follow her food adventures on Instagram and Pinterest.

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