See how to make a roux for mac and cheese sauce! Classic roux is made with 2 ingredients, butter and flour, and used to thicken creamy sauces like bechamel and cheese sauce. In this post, you’ll learn all the tips and tricks to make perfect cheese roux every time.
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Mac and cheese roux
Many mac and cheese recipe call for a roux. But what exactly is that and how do you make it? Don’t feel intimidated! In this ultimate guide, you’ll learn everything you need to know about mac and cheese roux.
We talk about ingredients, the cooking process, and common mistakes. You’ll learn plenty of tips to ensure your mac n cheese roux turns out perfect every time.
What is a mac n cheese roux?
How do you pronounce roux?
First things first, how do you say roux? Roux is a term from French cuisine and pronounced “roo” (/ˈruː/).
What does a roux do in mac and cheese?
Roux works as a thickener for mac and cheese sauce. It provides the base for the sauce. Milk and cheese are then added to complete the sauce.
Without a roux, mac and cheese sauce would be more liquid. Thickening ensures the sauce turns out creamy + rich and clings to every noodle.
Roux is also the classic way to thicken gravies, sauces like bechamel and velouté, soups, and stews like gumbo.
What is roux made of?
You’ll only need two ingredients to make roux, fat and flour:
- Fat: Roux is often prepared with butter as the fat component. However, it can also be made with other edible fats such as vegetable oil, clarified butter, lard, or bacon drippings.
- Flour: Wheat flour is the thickening agent for roux. During cooking, the starches in the flour absorb moisture and begin to swell, thickening the sauce.
What is the roux ratio?
Roux is traditionally made from equal parts fat and flour.However, the mac and cheese roux ratio of my recipe is more than 2 to 1 because using more butter creates a better texture and flavor.
How do you make a cheese roux?
First, the butter is melted on the stovetop. Then the flour is whisked in and cooked over medium heat for a couple of minutes. The mixture is cooked until a smooth paste forms and the raw flour taste is gone.
The next step is to whisk in the milk, which creates a thick and creamy bechamel sauce. The bechamel is just the start of the cheese sauce, because we’re adding plenty of cheese to make a delicious mac and cheese sauce.
We already looked at butter and flour, now let’s talk about the other ingredients you need to make the cheese sauce. Check the recipe card at the end of the post for specific measurements.
- Butter is a key ingredient to make roux. You can use both salted and unsalted butter.
- Flour: You’ll need all-purpose flour for the roux. For accuracy, measure the flour with kitchen scales. Alternately, use the spoon-and-level method, where you spoon flour into the measuring cup and then level off the top with the back of a knife.
- Milk: I recommend whole milk so the sauce becomes luscious and creamy. Of course, you can also use 2% or skim milk. Although some recipes suggest warm milk, the milk should be cold or at room temperature. I explain this more in the troubleshooting section below.
- Cheese: You want an aromatic cheese that melts well. I used gruyere, but you can also use cheddar, gouda, Monterey Jack, Colby Jack, or Swiss cheese. For more info, check out this mac and cheese sauce recipe.
- Seasoning: Salt and pepper are all you need to season this homemade mac and cheese roux. I also like adding a bit of smoked paprika for more flavor, but that is totally optional.
You need a heavy-bottom saucepan or pot, a whisk, and a wooden cooking spoon or heat-resistant spatula. I always have the best success with my enameled cast iron pot.
Last but not least, your choice of pasta! Any short pasta will work here, classic elbow macaroni, shells, cavatappi, bowties, penne, fusilli, or rotini. The noodles you see in the pictures are called lumaconi.
How to make roux for mac and cheese
Time to get cooking! I’ll break it down for you with step-by-step instructions and process photos so you can see how easy it is to make roux for cheese sauce.
#1: Melt butter
- Place the butter into a large, heavy-bottom saucepan or pot. Melt over medium heat.
#2: Add flour + spices
- Sprinkle the flour and spices onto the melted butter and whisk vigorously to combine.
#3: Cook roux
- Whisking often, cook over medium heat for 2 to 3 minutes.
- At this point, the mixture should look smooth, and the raw flour taste should no longer be apparent.
#4: Add milk
- Slowly pour in the cold milk, while whisking continuously, until combined and smooth.
- Continue to cook over medium heat, constantly whisking, until thickened.
#5: Check consistency
- Once thickened, the roux sauce should have a smooth texture and thick consistency that can coat the back of a spoon. It should leave a line if you run your finger through the sauce. This quick test indicates that the sauce is ready.
- Remove the sauce from the heat.
#6: Stir in cheese
Add the grated cheese and stir until well incorporated and fully melted. If it doesn’t fully melt, return the pot to the stove and warm it over low heat.
- At this point, taste the sauce and adjust the seasoning to your liking.
#8: Add pasta
- Fold in your cooked pasta until coated and serve hot. Enjoy!
My cheese roux is too thick
If you accidentally added too much flour or cooked the sauce a tad too long, your sauce might turn out thicker than intended.
Fix: It’s easy to thin out the mac and cheese sauce! Simply add more milk until the desired consistency. Add the milk in small increments, 1/8 cup or so, and whisk it in fully before adding more.
The mac n cheese roux is too thin
The opposite can also happen: If you used too little flour or didn’t cook long enough, the sauce may end up too thin or watery.
Fix: First, continue cooking the sauce until it boils down to a thicker consistency. You can also add more cheese to thicken it.
The sauce tastes like flour
When roux is properly cooked, there should be no floury or starchy taste. A raw flour taste means that the roux is undercooked.
Fix: You can avoid this by cooking the butter-flour mixture for at least 2 to 3 minutes over medium heat. This will cook out that raw flavor from the flour.
Help! My mac and cheese roux is clumpy or gritty
There are several reasons why your mac and cheese roux may turn out lumpy or gritty. Here are the 3 common mistakes and tips to avoid them.
Problem 1: Hot milk
Some recipes advise adding warm or hot milk to the roux. But if the liquid is too hot, the roux doesn’t have time to properly disperse in the milk before the mixture comes to a boil, which causes lumps.
Fix: Instead, use cold or room temperature milk. Using cold milk allows time for the roux and milk to mix properly before the mixture boils and thickens.
Problem 2: Overheating
If you cook the sauce too long or too high, it can burn to the bottom of the pan, resulting in an uneven texture with burned bits throughout. Overheating also causes starches to break down, and the viscosity of the sauce starts to thin.
Fix: Cook the roux and sauce at medium heat. You might even get away with medium-low heat if you have a strong stove.
Problem 3: Cheese
The type of cheese affects the smoothness of the sauce as well. You want to avoid pre-grated cheese.
Manufacturers coat pre-grated cheese with anti-caking agents like cellulose and cornstarch to prevent sticking. As a result, the cheese won’t melt quite as well and can make the sauce grainy.
Fix: For the smoothest sauce, grate your own cheese from a block of cheese and use a hard grating cheese with high moisture content.
The cheese sauce has split or is oily
Splitting occurs when the cheese is added while the sauce is too hot. The heat causes the cheese to break down into protein and oils, and the sauce separates and becomes oily.
Fix: Don’t add the cheese while the sauce is boiling or bubbling. Instead, take the pot off the heat and wait until the sauce has stopped bubbling.
How much does this cheese roux recipe yield?
This roux recipe for mac and cheese makes approximately 5 cups cheese sauce, which is enough for 1 lb noodles and should feed 6 to 8 people. We like our mac and cheese extra saucy, so I usually only cook 8-10 oz / 250-300 g pasta.
Can I make roux with gluten-free flour?
Yes, you can make a gluten-free mac and cheese sauce, substituting regular ap flour with a gluten-free 1-to-1 flour blend.
I recommend Bob’s Red Mill Gluten-Free 1-to-1 Baking Flour and King Arthur Gluten-Free Measure For Measure Flour. You could also use oatmeal, but the flavor and texture will be different.
Can I make roux without flour?
Yes, you can prepare roux with cornstarch, potato starch, or arrowroot powder instead of wheat flour. Check out this mac and cheese sauce recipe for a version with cornstarch.
It’s also possible to prepare mac and cheese sauce without flour. In fact, we have 2 tasty recipes on the site for flourless mac and cheese sauce:
- Mac and Cheese without Flour: This no roux mac and cheese recipe skips the flour and uses lots of cheddar and American cheese to thicken the sauce. So good!
- 4 Ingredient Mac and Cheese: This is the simplest mac and cheese you could possibly find! It uses only pasta, white cheddar, parmesan, and milk – no flour in sight!
- Store: Store leftovers tightly covered in the refrigerator. Mac and cheese will keep well for 3 to 4 days.
- Reheat: Stir a bit of milk into the pasta and microwave in 30-second bursts until heated through. Stir between each burst.