In this recipe for mac and cheese that calls for a basic roux of 1/4 cup flour and 1/4 cup butter (60g from what I gathered it to be) I got a pretty thick sauce even after adding 3 cups of milk and before I added any type of cheese.

I wonder - can you do something in the roux-making that can cause the flour to over-thicken?

  • Too little liquid for the flour/butter mix. Not the preparation, only ratios.
    – Stephie
    Apr 13 '16 at 13:17
  • Related: cooking.stackexchange.com/questions/21329/…
    – Stephie
    Apr 13 '16 at 13:20
  • 2
    1/4 cup of butter is about 60 grams but 1/4 cup of flour is only 32 grams. If you used 60 of both, that's not what the recipe calls for, so you've got way too much flour.
    – Catija
    Apr 13 '16 at 14:22

Based on your description, it looks like you've made the common error of assuming that equal volume is equal weight.

Butter is more dense than flour so the same volume does not equal the same weight... you must convert the 1/4 cup for each product using a trustworthy site.

Here's one that looks OK and includes both butter and flour.

As you can see, 1/4 cup of butter is 57 grams. If you look at the next chart, you see the conversion for flour and you can see that 1/4 cup of flour is only 32 grams!

This means that, if you added 60 grams of each, you've got twice as much flour (the thickening agent) than the recipe calls for... so of course it's going to be way too thick.

I recommend you start over and be more careful with your conversions.

As a note, my standard recipe for Mac and Cheese uses 4 tbsp each of flour and butter (generally equivalent to 1/4 cup) while it only calls for two cups of milk rather than three, so I usually have a much thicker white sauce than yours will be and I find it quite enjoyable.

The Joy of Cooking (an iconic American cookbook) recipe calls for the same percentages for their white sauce - 2:2 tbsp of butter/flour with 1 cup of milk.

To answer your questions in the comments, pure butter (rather than spreadable butter/margarine or butter blends) in the US is usually sold in one pound boxes containing four sticks per box. Each stick is 1/4 pound of butter which is equivalent to 1/2 cup. Each stick is wrapped in waxed paper and has tick marks to show each tablespoon of butter for a total of eight tablespoons.

Sticks of Butter

Occasionally the paper isn't perfectly aligned but it's usually a simple matter to adjust your cut position to allow for the offset.

So, a cup of butter is two sticks, a 1/4 cup of butter is a half stick. and a tablespoon is 1/8th of a stick.

Your second question I think comes from a misunderstanding of how thick the white sauce is when completed correctly. With the proper percentages of flour and butter (and using two cups of milk), the final consistency you get is somewhere between thick cream-based soup and thin hummus. Adding the cheese usually doesn't effect the thickness because the cheese melts and is about the same consistency as the white sauce. I also like adding softer cheeses that melt well like goat cheese for both flavor and textural reasons.

Once baked, the final outcome will be fairly solid and casserole-like. You should be able to cut it with a knife and expect it to hold its shape to a good degree, like this:

Baked Macaroni and cheese

This recipe will not make the creamy-style macaroni and cheese (an example is shown below. That is a different process and is generally not baked.

Creamy macaroni and cheese

So that you can see the differences in the recipes of baked and creamy styles I'll link you to a couple "creamy-style" mac and cheese recipes from other sources. This is a simple example recipe from Whole Foods Market, an American grocery chain and here's a slightly more complicated recipe from Serious Eats.

  • Got 2 questions for you catija: 1. How can you measure in a cup something like butter which is solid? 2. If you use 4tbsp of flour and butter and use only 2 cups of milk - how in the world do you manage to get some cheese inside that already thick mixture?
    – Bar Akiva
    Apr 14 '16 at 6:01
  • You can weigh the butter too, you just need to go look up a conversion (or ballpark it from the fact that 1lb is 2 cups (four half-cup sticks). So it's 227g per cup.
    – Cascabel
    Apr 14 '16 at 14:32
  • @Jefromi Sure... but most Americans don't weigh anything when they cook and most US-based recipes mention measurements in tbsp or cups.
    – Catija
    Apr 14 '16 at 14:39
  • @Catija But the OP is presumably not American (measuring things in grams), and may not even have butter with the markings on it, so weight is likely the best way for them to measure. (Maybe I'm misunderstanding the context of the OP's question here, though - I thought they were still having trouble, not just questioning how Americans measure.)
    – Cascabel
    Apr 14 '16 at 14:56
  • @Jefromi Oh, I was confused because my answer includes the conversion already.
    – Catija
    Apr 14 '16 at 15:12

No, you can do something to underthicken it (make a darker roux than the recipe intended by accidentally heating for too long), and you can get lumps in it, but there is no common mistake(1) which can cause too thick a sauce.

From your description, it seems like you simply used way too much flour. 120 g to the cup is a pretty common conversion factor for flour (as always with volume-to-weight conversion, it's not perfect, but good enough). 1/4 cup of flour would be 30 gram, not 60.

Also, this recipe seems flawed in suggesting a 1:1 ratio for the roux to weight instead by volume. You probably needed 30 g flour and 30 g butter, not 30 flour and 60 butter. Sometimes it is common to overbutter roux, but not by such a margin, and the additional fat is more commonly added later, not during making. The 1:1 volume ratio suggests the recipe maker didn't know what they were doing, so I wouldn't be surprised at the recipe as a whole being suboptimal.

(1) Before people start correcting me: Technically, there are ways to overthicken. For example, you could cook out most of the liquid, but you'd need to forget it on the stove for an hour or two, and if that happened, you'd probably would be complaining of burnt sauce instead of thick sauce. Also, if you somehow managed to add another thickener without noticing, such as throwing in a pinch of xanthan insted of pinch of salt - you see we're dealing with extremely improbable scenarios here.

  • 2
    The traditional roux recipes I see (in the US) are always 1:1 by volume. Generally 1tbsp flour to 1tbsp butter and up from there. I've been making roux this way for white sauce... for macaroni and cheese... always.
    – Catija
    Apr 13 '16 at 13:59
  • @Catija interesting observation! The Professional Chef, a US textbook, says 60% flour, 40% fat by weight. Ruhlman's Ratio, also a US book, uses the same formula. I wasn't aware that a different ratio is also widespread - I'm not surprised by the fact that it is measured in volume, but that the ratio is so wide off from both the European style and the US textbook style.
    – rumtscho
    Apr 13 '16 at 14:10
  • 2
    I have a feeling that it was simplified a long time ago to be easy to remember and we overdo the milk to help thin it out more. In fact, I'm surprised that this recipe was too thick... my normal recipe is 4 tbsp each flour and butter (equivalent to 1/4 cup) and only 2 cups of milk... so it's less milk and I get the expected outcome.
    – Catija
    Apr 13 '16 at 14:21
  • Did you note it is not only the ratio that is off, but the conversion? He used 60 g flour when the recipe specifies 60 ml, that is 30 g.
    – rumtscho
    Apr 13 '16 at 14:26
  • I think my last comment on the question addresses that? I'm writing an answer at the moment.
    – Catija
    Apr 13 '16 at 14:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.