The first batch I threw out.
The second try was at least edible…but not smooth, creamy, or cheesy.
It was grainy and saucy.
I want smooth, creamy, and cheesy.
Heeeeelp!
Thanks 
First you open the box…
much prefered by my kids.
I assume you are talking about boxed macaroni. If not, I haven’t a clue but jayjay’s link looks good.
After you drain the noodles, put them back in the pot on low heat. Add the butter and half the milk; stir until the butter melts. Add the cheese packet - try not to dump it in a heap, but spread it out over the noodles. Pour the rest of the milk on top and continue stirring until the powder dissolves. Add more milk and butter if your macaroni is too dry and clumpy.
In my experience, the butter makes macaroni cheesy and creamy. Heating the macaroni while you stir should get rid of the graininess.
Hope this helps!
Easy. Make a roux – equl parts flour and butter. Add milk. Add grated cheese. Stir, stir. Stir all the time. You should end up with a cheese sauce. Use it to dress macaroni. If you like, drop the mixture into a casserole or shallow roasting pan, top with panko, bread crumbs, more cheese, whatever, and finish in the oven (optional). It will take some experimentation, perhaps, to adapt to your range, cookware, and personal tastes. Persevere, above all else.
Two of everything.
Melt two tablespoons butter, stir in two tablespoons flour. Add two cups milk. Cook over medium heat, stirring damn near constantly (seriously, don’t try to grate the cheese during this part), until the milk is thickish and bubbly. Then add the two cups of grated cheddar or whatever (many people like to mix a variety of cheeses) and stir until melted.
Meanwhile, you have hopefully remembered to get some water boiling and cooked two (dry) cups of macaroni. Mix that into the sauce. Pour into a pan and bake at 350 for half an hour, or until the crust approaches your desire.
I did EXACTLY what Frank and Epicurious said.
Grainy, grainy, grainy. It was as if there was no cheese at all.
As for the people recommending recipes with Velveeta brand plastic cheese…or the box kind…YEESH! 
I see you’re still signed on, so are you looking for stovetop or baked or do you care?
Sounds like the flour is settling out.
Make sure the flour is completely mixed with the butter. Then, after you’ve added the milk: Stir. Stir. Stir. If there are little lumps in the sauce, you’re not stirring enough.
I don’t know what milk you’re using. I’d suggest using 2% milk at the lowest. Skim or 1% doesn’t have enough fat in it. Whole milk works best, especially when you’re learning the sauce.
It’s really just a basic white sauce, with a million uses once you get it figured out. For instance, you will then be able to make home-made shit on a shingle and tuna noodle casserole. Keep practicing!
Yeah, I’m doing all of that. I make chicken pot pie the same way and end up with an extremely creamy sauce.
Still, though, with 2 cups of milk (and I used whole) to the two cups of cheese…it seems like it’s not much cheese.
The funny thing is, I’ve never had home made mac and cheese before. So maybe I don’t know what I want, but what I’ve tried (two different styles) ain’t workin’ for me. Inedible.
Someone asked if I want stovetop or baked…I guess baked? It starts out on the stove (cream sauce) then gets baked.
Yes! The Patti LaBelle Over The Rainbow Mac & Cheese is the one and only recipe for it you will ever need. Everything else pales in comparison.
But be forewarned, it really is a heart attack on a plate, so try not to get addicted to it.
Recipe for baked Mac and cheese from America’s Test Kitchen family Cookbook[ul]
[li]8 tablespoons butter[/li][li]2 cups fresh breadcrumbs[/li][li]1 pound elbow macaroni[/li][li]1 garlic clove, minced[/li][li]1 teaspoon dry mustard dissolved in 1 tsp water[/li][li]one quarter teaspoon cayenne pepper[/li][li]6 tablespoons all purpose flour[/li][li]3.5 cups whole milk (as Frank points out do not use low fat or 1 or 2%) 1.75 cups low-sodium chicken broth[/li][li]1 pound colby cheese[/li][li]8 ounces extra sharp cheddar shredded about 2 cups[/ul][/li]Directions:[ul]
[li]Adjust rack to middle and preheat oven to 400. Add breadcrumbs to 2 tablespoons butter and set aside[/li][li]Bring 4 quarts water to a boil in large pot and add one tablespoon salt and cook macaroni until almost tended but firm to the bite (al dente). Drain and leave in colander.[/li][li]Wipe pot dry and add remaining butter and melt over medium heat. Stir in garlic, mustard mixture and cayenne and cook until fragrant about 30 seconds.[/li][li]Stir in the flour and cook until golden, about one minute. Slowly whisk in the milk and broth. Bring to a simmer and cook, until slightly thickened, about 6 minutes.[/li][li]Off the heat, stir in the colby and cheddar cheese until completely melted. Season with salt and pepper. Stir in drained macaroni, breaking up clumps, until well mixed.[/li][li]Pour into 9 by 13 baking dish. Sp[rinkle with breadcrumbs. Bake until golden brown and bubbling around edges, about 25 to 30 minutes. Let cool for 10 minutes and serve.[/li][/ul]
The two keys are the flour/butter mixture (roux, which takes practice but if in doubt lower the temperature) and slowly mixing the cheese to obtain a good emulsion.
Hey, you wanna miss out on the single best macaroni & cheese in the world because of some kind of food snobbery, be my guest. More for me!
If you’re making a proper roux/bechamel sauce, try using a small balloon whisk to stir it - much easier to avoid lumps that way; no need to grate the cheese - just cut it into little cubes and it will still dissolve/melt into the hot sauce just fine. Add a half teaspoon of mustard to the sauce to enhance the cheese flavour - it really works.
Make sure you drain the pasta throrougly - macaroni pasta types are good at trapping water and too much will make the whole thing sloppy.
Also, try it with a mature cheddar type cheese, rather than one of those mild rubbery ones, or you could use Emmental or Jarlsberg/Leerdammer for a different taste. Maybe even roquefort or stilton.
You’ve got the sauce too hot after adding the cheese or you didn’t get the flour mixed well enough. Since you’ve had success with other sauces, I’m betting on the too hot.
You may have added the butter too fast or had the sauce on the heat too long. This can result in a “broken” sauce. This usually happens with an egg sauce such as Hollandaise, which can be fixed by using a little lemon juice: whisk a tablespoon of lemon juice with a tablespoon of the broken sauce until creamy; then drizzle the rest of the sauce into the mixture, whisking as you go and making sure the sauce is reconstituting before adding more.
Don’t be afraid to adjust the recipe.
The first time I made mac&cheese I used a recipe from the Doubleday cookbook, basically what others have said - a white sauce plus cheese. I don’t remember how much cheese exactly, but two cups sounds about right. It wasn’t anywhere near enough. I ended up using a whole block of cheese in the sauce, plus more on top when I baked it.
Give the Test Kitchen recipe a try - you can almost always trust them to be pretty good.
Isn’t that cookbook the BEST? I love it beyond words. I haven’t made their mac + cheese yet but I’ve tried a bunch of others and they have all turned out great. (In case people don’t know, this cookbook is put out by the same people who publish Cook’s Illustrated magazine - IMO the best cooking magazine around.
I believe they explain in the book why the sauce can turn grainy; I think it’s what Chefguy said about being “broken.”