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Jan 22, 2007 02:45 AM

Mac n Cheese -- Why does my sauce separate?

I've tried various mac n cheese recipes and always my sauce separates and seems oily. WHY?? What's your favorite recipe?

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  1. Assuming you're making a bechamel sauce: it's probably the cheese melting at too high a temperature. Some cheeses (like cheddar) tend to separate and get oily/grainy. Here's a couple hints:

    1) Use a mix of cheeses, including some that melt more smoothly. My faves include asiago, fontina, gruyere, or even gouda (for a bit of a different mac n cheese flavor). I like the sharp cheddar taste, but using more than about 1/2 cheddar risks separating and graininess.

    2) Add the cheddar last, and only after you've turned off the heat. Stir well until melted and mix into the pasta...

    Good luck!

    1 Reply
    1. re: another_adam

      Don't forget blu cheese :)

      Adam is right on this one- the big thing is whisking in the cheese after you remove from the heat. The way I do it is to put my large sauce pan on my cutting board and slowly whisk in the cheese, not adding more until the first bunch is melted.

      Last recipe I used I went with 3 cups of shredded cheddar (a combination of smoked cheddar and extra sharp) to 1.5 cups of crumbled blu cheese.

    2. are you binding the sauce with a roux (flour and butter) or cornstarch? you need something to hold the milk and cheese together. if not, you could heavily reduce heavy cream (till it thickly coats the back of a spoon) and add the cheese. using cream cheese will help bind it as well.

      1. melt butter, add flour (equal parts each), wisk to form the roux. cook for 2 minutes on medium.
      2. add milk slowly, wisking to prevent lumps. let it come to a boil and simmer for 10 minutes.
      3. add desired cheese (i use cheddar, parmesan, and cream cheese.) you can remove the pan off the heat when you add the cheese.

      9 Replies
      1. re: Antonio Montana

        oh yes, a little cream cheese also adds a kind of sinfully rich creaminess to the bechamel (asiago has a similar, but "cheesier" effect)

        what kind of parmesan do you use? i would have thought it would separate or get stringy, too...

        1. re: another_adam

          Cream cheese? I've never thought of that... very interesting. I'll definitely have to experiment with it.

          To the OP, as others have said, if you are doing pure cheddar and nothing to bind it (roux, stabilizer, etc.) then you'll always get some separation. With something like a gruyere, you can get away with it, but a mix is best. I actually like 2/3 sharp cheddar and 1/3 monterey jack. A bechamel works well to bring it all together in the right consistency. However, I'm not a huge fan of a bechamel flavor in mac and cheese. I've started experimenting with gums, like guar gum, as a stabilizer for cheese sauces.

          1. re: adamclyde

            Wow, this does indeed sound like a project for food scientists (we need a "Cornell Mac 'n Cheese"!)

            I've always wondered about applying some fondue-stabilizing techniques. Swiss acquaintances have told me that a little creme fraiche helps (maybe similar to cream cheese?) And laying out the grated cheese to dry for at least an hour or two before melting.

            One other suggestion for the OP: are you using a recipe with egg? If so, you need to be sure to bake at a lowish temperature, maybe even in a water bath, so it all cooks gently and evenly without "breaking"

            1. re: another_adam

              I just like your posting name. :)

              I've never thought of using creme fraiche in mac and cheese, though I can see how that works. It certainly works well in cream or milk-based pan sauces, as creme fraiche withstands heat quite well.

              1. re: adamclyde

                An easy recipe for creme fraiche is to mix at room temperature a cup of heavy creame with either 1/2 cup sour creme or 1 T buttermilk, also at room temperature. Cover and shake for 15 seconds. Leave stand at room temperature for 24 hours, mixing occasionally. This can be refridgerated for 2-3 weeks.

            2. re: adamclyde

              Alright Adam, breaking out the guar! :)

              How do you like it so far?

              If you want to take it to the next level, combine guar with xanthan. They have a phenomenal synergy with each other.

              Bechamel does tend to give cheese sauce a bit of a bready/cerealy note. Are you looking to bypass the bechamel completely? If this is your goal, I'd recommend combining the gums with arrowroot. Arrowroot lends a much cleaner taste to cheese sauce than flour does, and, by sharing the load, you won't overdo the gums/create sliminess. The other nice thing about an arrowroot/gum sauce is the time saved from not having to make a roux. Just sprinkle/whisk the gums and use a slurry for the arrowroot.

              The one tip I'd recommend for working with guar is to get it into the milk/cream right off the bat- first thing. I find that no matter how carefully you incorporate gums, there's almost always a little clumping. Heat helps break down the clumps, to an extent, but time is invaluable. The longer the gums have contact with the liquid, the better.

              1. re: scott123

                been using it in different applications, on your encouragement, thanks very much, btw.

                Like it so far. Mostly been in ice cream, but started a few weeks ago experimenting with cheese sauces too, since I've never liked flour thickened cheese sauces for some reason. They just taste flour-y to me.

                If I could find Xanthum in smaller quantities, I'd grab some, but so far, I can only find it in gigantic bottles... I'll keep looking though.

                1. re: adamclyde

                  You're welcome.

                  It is kind of ridiculous the amounts of xanthan they sell. With the xanthan I got from Whole Foods, it's probably enough to last 3 lifetimes and I use it just about every other day. As far as I know, it keeps forever in an airtight container (I use a glass PB jar), though, so I'm not worried about it going bad.

                  If you've got an issue with the flour-y taste of bechamel, I have two suggestions.

                  1. Take the roux to a slightly darker shade. Instead of a 1 minute-ish white roux, try a blonde roux, or maybe even slightly beyond that. Think liquid shortbread. As you toast the flour, it gets a nutty character and the taste changes dramatically. Just make sure the heat is low so the flour toasts evenly.

                  2. Simmer the bechamel for 10 minutes... maybe even 15. Simmering a flour based sauce goes a very long way in breaking down the starch granules and removing the floury taste. Gravy is complemented by extended simmering as well.

            3. re: another_adam

              I'm not sure of the chemistry involved, but I have found cream cheese to be exceptionally UNstable in cheese sauce. I've had more cream cheese sauces curdle on me than any other type of cheese.

              The other thing that I noticed about cream cheese based sauces is that they store poorly. If, by babying the heck out of it, I am lucky enough for the sauce not to curdle, if I then refrigerate it overnight, it's toast.

              My handful of experiments with cream cheese have been at fairly high concentrations. Maybe if you use just a little, it might be alright.

              From my experience, though, I definitely view cream cheese as a de-stabilizing force.

          2. Are you thoroughly draining the pasta after boiling? Those macaroni tubes can hold a lot of water.

            1. I have used this recipe over the years with much success. I saute a few tablespoons of finely chopped onion in butter first before adding the flour to make the roux, but otherwise stick to the recipe. I have made it with parmesan and cheddar as called for, but also have used other cheeses when I needed to clean out the refrigerator -- if it shreds, grates or crumbles I'll use it. In addition to making the roux properly, the parmesan helps to keep the cheddar from separating. I always use some amount of good quality extra sharp cheddar in addition to other cheeses and have never had a separation problem.

              1. I love mac and cheese and I love all the variations, actually you can switch it around with the cheeses. If I don't make a bechemel sauce first, the cheeses just don't adhere to the pasta like it does with a base sauce first. One of the best recipes I've tried is to make your bechemel, add your cheeses, pour it over the pasta into a casserole and then taken a beaten egg and mix it in with the pasta. cover with extra cheese, and lots of bread crumbs, bake at 350 until bubbly then brown the top if it isn't under the lowest setting under the broiler. I believe this might be more southern style mac and cheese. But served with fresh cold tomatoes, and hot sauce it is terrific! Left over mac and cheese can then be made into balls to fry.
                Well, I never said it was low cal.....