i've had great success with using velveeta. don't all hate me at once. i'd been making mac and cheese for years and sometimes encountered the same problems mentioned above. now i just make sure that i use a small chunk of velveeta and add in the rest of the cheese while the pasta is hot. the velveeta just seems to help hold things together and is much easier/faster than a mornay or bechamel.

i've had great success with using velveeta. don't all hate me at once. i'd been making mac and cheese for years and sometimes encountered the same problems mentioned above. now i just make sure that i use a small chunk of velveeta and add in the rest of the cheese while the pasta is hot. the velveeta just seems to help hold things together and is much easier/faster than a mornay or bechamel.

I'm sure the problem is that the roux is too hot when you add the cheese. If you have an electric stove make sure to move the pot off the burner when you add the cheese, just turning it off isn't enough. Cheddar is the worst offender.

I agree: too hot. I always scoop half a cup of the starchy pasta boiling water before draining, and use it to thin the mornay sauce after I pour it over the macaroni. My sauce is usually too thick to coat nicely without this step. If I turned up the heat a little, the sauce would be runnier--and greasier.

The best recipe I ever tried was Cheesy Mac's Mac and Cheese, from the book "Kitchen Scraps" by Pierre Lamielle. It calls for 4 different kinds of cheese and is a little time consuming but absolutely worth it, not to mention the calories... For special occasions only.

I always thought that this was a problem with highly processed cheese that has a high oil content. When baked the "cheese" separates into milk solids and oil...

I always do a roux as well- are you adding the milk before the cheese, or after? I don't know if that makes a difference, but I've had very good luck with making the roux, whisking in the milk and then adding the cheese. Sometimes if I have some cream cheese in the fridge, I'll add a dollop of that, as well and I think that helps with the texture some. I've developed a pretty fool-proof formula for baked mac and cheese that is highly customizable:

makes an 8x8 pan
-1/2 lb. noodles
-1/4 c. butter
-1/4 c. flour
-3/4-? c. milk
-8 oz. cheese (any cheese you want, but keep texture in mind. 4 oz. havarti and 4 oz. smoked gouda are great together because the havarti is so soft)
-panko bread crumbs (toast in butter or better yet, BACON FAT) for the top

Cook the noodles and then drain. Using the same pot, melt the butter, add the flour to make a roux- cook about 1 minute. Whisk in milk starting with about 3/4 c., increase gradually until smooth (not lumpy, but not soupy). Add in grated cheese, stir until melted. Add noodles. Stir in milk if necessary to achieve texture. Plop in greased pan, top with toasted panko, bake at 350 for about 10-15 minutes. Bam.

I made this recipe last night: http://www.thekitchn.com/weeknight-recipe-easy-homemade-82588

I've made it made times and have never had a problem with the sauce separating or becoming oily.

I will often ruin a mornay, leaving it grainy and soupy. However, I stopped worrying about it when I learned a quick zap with an immersion blender makes any botched sauce creamy.

Are you using a quality natural cheese? Cheap "cheese" or certain varieties of real cheese are less stable.

Thank you for all of the ideas and comments!
I always use quality cheese, usually a blend of grated fontina, havarti, and gruyere. I follow the exact steps that KirstenWI listed above, but I have never heated the milk prior to adding it to the roux base. Perhaps that is the problem? I also wonder if I could be using too much butter in the roux while also keeping it too hot throughout the whisking together process. I'll try these tips this weekend! Thanks!

Megan: If you are indeed starting with a bechamel sauce (seriously people - Mornay?) keep heat on low after acheiving a smooth, lump free sauce and add in the cheese slowly either grated or cut into small chunks (I use sharp cheddar). I've made my mac & cheese dozens of times now, and never had a broken sauce as you describe. Even after baking, sitting in the fridge, and warming up in the microwave it's creamy. What kind of milk are you using? I use 1% for the recipe below (enough to feed like 8 people):

My bechamel starts with 1 stick of butter, enough flour to make a thick but still loose roux (maybe 1/2 cup), cook while whisking 1-2 minutes on med-low heat. Add 4 cups warm milk (it just gets to the final stage faster if the milk is warm), whisked in until smooth and no lumps (med heat to get it to simmer). Whisk, whisk, whisk. Add your cheese while whisking with any other seasoning or goodies you want in there (low heat). When sauce is smooth mix it in with your cooked (firm, 2 lbs) pasta, put in baking dish, add breadcrumbs if that's your thing, and bake until top is crunchy at 350F.

I hope you find success!

velveeta all the way

Hi Jess13,
Thanks for the tips. I was using half and half, not milk. Maybe the fat content is too high for the sauce and that's why it breaks? I also found that using about the same proportions as you stated, that there just wasn't enough cheese sauce to cover 2 lbs of noodles (small spiral).
I'm going to try it with heated 1% milk this weekend and will add the cheese slowly as I take the sauce off of the heat.

On a side note- has anyone ever added truffle oil to your macaroni and cheese? I have been experimenting with that as well, but it only seems to add to the oiliness. I can't figure out at which point to add the truffle oil in to the sauce.

Thanks!

My favorite mac and cheese recipe was the top-selling item at a restaurant where I used to work. Just reduce cream until it's nice and thick, throw in a healthy dollop of dijon mustard both for flavor and to hold the emulsion, then dump in all of your cheese off the heat while the cream is still hot. I like to use goat, gruyere, and parmesan. The goat makes it tangy, the gruyere is cheesy and goopy, and the parm dries things out just a tad and cuts down on the salt you have to add later. Stir that sauce in with cooked noodles and an egg or two, then portion it and pour some more sauce on top. Top all of that with a melty cheese like fontina or cheddar and bread crumbs mixed with melted butter and some truffle oil if you want. Pop that in a 400 degree oven until it's brown and bubbly, and enjoy. It may be a bit of a production, but it's some of the best mac and cheese I've tried, and I've never had it break. As a bonus, you can save any leftover sauce you have. It's great for fondue or random unhealthy snacking.

Oh it is definitely the half and half. There is way too much fat in your sauce for the flour to absorb.
Use whole milk, and heat it before adding it to the roux to keep it from breaking. You can use 1%, but you might want to add a splash of half and half to help improve the mouthfeel.

If you only keep half and half on hand, then keep in mind the following: half and half is about 20% milk fat. Whole milk is about 4% milk fat, so if your recipe calls for a cup of milk, Take 1/5th a cup of half and half and add 1 cup of water. (The warm pasta water will work and save you time, and counteract the problem of the oiliness).

The only one that mentions baking is the last one.....but that's a little more involved than I want to do. What if I'm doing Mornay/Bechamel, throw the sauce over noodles, and bake.....is the mixture destined to separate then too, or is there something someone can recommend for me? Yes, I do put the cheese in when the sauce is hot....it's got a food-processor grade grate.I use whole milk in my sauce (or 2% sometimes, if that's all I have). What gives?

I meant "Take 1/5th a cup of half and half and add water till you have 1 cup of fluid total. sorry."

I keep shelf stable UHT boxes of whole milk for exclusively this purpose. I heart me some mac and cheese.

Lastly, if you undershot the flour/butter ratio and have an oily sauce that you want to 'fix' rather than eat, you can always add a flour or cornstarch slurry (a mix of cold water and a couple spoonfuls of starch). (Cornstarch has less flavor, but a different (glossier) texture. Flour will add a more raw flavor, but is more flexible with heat. ) Add about a quarter cup of cold water slurry, stir in, bring to a boil, and your sauce should improve.

If you are worried about the truffle oil, use truffle salt as a finnishing salt... Same flavor without the mess. I got mine at The Cheese Store of Beverly Hills. It lasts forever without going rancid like oil can. http://www.cheesestorebh.com/Store/ProductDetail.asp?ProductID=345
Good luck!

A splash of lemon juice keeps the melting cheese from becoming stringy. That could also help the oil blend in.