A roux in a pan with ingredients around it

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Making a recipe that requires a roux but wondering where to start? Well, you’re in the right place. Find out everything you need to know about what it is, what it’s used for and how to make a roux. Plus we’ve thrown in a few extra bonus tips!

What exactly is it?

A roux (pronounced “roo”) is a simple mixture that is made to thicken sauces, soups and gravy. It can be prepared in several different forms based on how long it is cooked for (see more about types below).

A roux needs only two very simple ingredients, flour and fat. Both these ingredients are used in equal WEIGHTS (you may see various sources telling you to use equal volumes, which is not the traditional preparation). Butter weighs around 50% more than the same volume of flour, therefore if you measure things by volume you will have a lot more butter than flour.

Roux ingredients

What is a roux used for?

Roux are used in a variety of recipes. Lighter roux (see types and variations) are used predominately to add thickness and body, whereas darker variations also add a lot of flavour to the final dish.

Even if you think you have been unfamiliar with what a roux is until now, the chances are that it’s a staple part of your favourite sauce. It’s actually the basis of 3 out of the 5 French ‘mother’ sauces. Including bechamel sauce (aka, lasagna white sauce), veloute and Espagnole sauce.

How to make a roux

Making a roux couldn’t be easier. First, melt the butter in a pan over medium heat. You can allow it to lightly bubble, but don’t boil it so it starts to brown.

Next whisk in the flour. A whisk will help you to really mix the ingredients together and get a smooth consistency, but a wooden spoon will also suffice if you don’t have a whisk to hand.

Keep whisking regularly and don’t let it scorch. The amount of time to cook it depends on what type you are making (see types and variations ). If you are making the most simple version, a white roux, then you want to cook for around 2-3 minutes after the ingredients are combined. You are just cooking it enough to start to loosen slightly and for the raw flour taste to go. Once the flour starts to cook it should start to smell a little nutty.

It should look like a thick paste when it is first made, almost like a dough. The longer you cook it the thinner it will become, but it takes some time for it to loosen so if you are making a lighter roux don’t expect it to thin out much.

Steps how to make a roux

What kind of fat should I use?

Butter is one of the most common fats to use in a roux. This is typically what you will see in French cooking. However, when preparing a darker version (see types and variations ) then something with a higher smoke point may be used due to the extended cooking time. This may be fat rendered from cooked meats, clarified butter or oil.

You can use a range of different fats based on what you have available and what you are making the roux for. However, I don’t recommend using margarine, as it has a lower fat content and will affect the taste of the dish.

How much do I need to make?

A roux in pan with flour and butter on the side

The amount of roux to prepare depends on the volume of sauce you are making. I typically use around 25g (0.9oz) each of flour and fat for every 500ml (2 cups) of liquid to thicken. Depending on how thick or thin you want the sauce to be you can increase or reduce this.

If you are making a darker roux then its thickening efficiency reduces the longer it is cooked, therefore you will need a larger amount to thicken your sauce.

What are the different types and varieties?

There are 4 main types of roux, the differences between each being the colour of the mixture, which is based on how long the roux has been cooked.

Different Colours of Roux
RouxCooking TimeSample Uses
White2-3 minutesWhite, milk-based sauces
Blonde6-10 minutesIvory coloured sauces, such as veloute
Brownapprox. 30 minutesDark stews and sauces
Darkapprox. 40 minutesRich Brown sauces and dishes such as gumbo
Roux cooking times: As a guide only, the actual time will vary based on your cooking utensils and the amount of heat used.

If you come across a recipe that simply states to use a roux, then use a white one.

Remember that the thickening power reduces the longer it is cooked, so you’ll need around 30-40% more of a dark roux to thicken the liquid than white.

When cooking a brown or dark roux reduce the heat to low or medium-low to stop it from burning during the extended cooking time. If you burn it it is effectively ruined, and you will need to start again!

Tips for success

There are a few tips you can follow to make sure your roux works perfectly, every time.

  1. When you are using a roux, always add cold liquid to a hot roux and hot liquid to a cold one. This will help stop it clumping a lumps forming.
  2. If you can, use a whisk.
  3. If you are making a white roux, make sure to cook it enough to remove the raw flour taste – you should be able to start to smell a nutty aroma.
  4. Be careful as the mixture gets very hot while cooking, particularly if you are cooking a brown or dark roux.

Can I make it in advance?

Most people don’t realise that you can actually make a roux in advance. In fact, it keeps for a long time, which is great if you are making a darker variety which has a far greater time investment.

Keep cooked roux in a sterilised sealed container in the fridge for up to 3 months. You can also freeze it for up to a year. You can portion it into an ice cube tray, or spoon dollops of it onto a plate, freeze them, and then transfer them into a freezer bag.

Looking for some great recipes to put your newfound knowledge to the test? Try:

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A roux in a pan with ingredients around it

How to make a roux

  • Author: caroline
  • Total Time: 7 minutes
  • Yield: 4 1x
  • Diet: Vegetarian


Find out everything you need to know about how to make a roux, what it’s used for and how much to make. Plus a few extra bonus tips!

The default recipe makes enough to thicken around 500ml/2 cups of liquid when using a white or blonde roux.


  • 25g / 0.9oz butter (see note 1)
  • 25g / 0.9oz flour (see note 2)


  1. Heat the butter over medium heat in a saucepan or frying pan.
  2. When the butter is melted whisk in the flour until fully combined. It should take the form of a thick doughy paste. 
  3. Now to cook the roux. The time required is based on the type of roux you need.
    1. For a white roux cook only for 2-3 more minutes to remove the raw flour taste. You’ll know it’s nearly done when it starts to smell a little nutty. 
    2. For a blonde roux cook for 6-10 minutes, until the mixture has turned a light brown/blonde colour.
    3. Cook a brown roux for around 30 minutes, until a rich nutty brown shade (a little darker than peanut butter).
    4. Finally, for a dark roux cook for around 40 minutes, until the mixture has turned really dark brown.


  1. You can use other forms of fat as an alternative to butter. Try clarified butter, oil or fat rendered from meat. 
  2. In most cases, plain/all-purpose flour is used in a roux. Since different flours have different thickening abilities it is better to play it safe and use plain in most cases.
  3. The longer the roux is cooked the less effective it will be for thickening sauces. Therefore make a larger quantity. A brown roux has roughly 30% less thickening power, so you will need 30% more. 
  4. You can make roux in advance. Store in a sterilised airtight container in the fridge for up to 3 months, or in the fridge for up to a year. If freezing you can portion it using an ice cube tray or freeze small blobs of it on a plate and then transfer to a freezer bag. 
  • Prep Time: 2 minutes
  • Cook Time: 5 minutes
  • Category: Sauce
  • Method: Hob / Stove
  • Cuisine: French


  • Serving Size: 1
  • Calories: 68
  • Fat: 5g
  • Carbohydrates: 5g
  • Protein: 0.5g

Keywords: roux, thicken sauces, thicken soup, thicken gravy, butter, flour, fat, classic

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