Mac and cheese Roux help

I need help to make a smooth cheese sauce for a Mac and cheese. Typically when I make it the end product comes out a bit gritty and I don’t love that. Trying to get away from the gritty texture.

My usual recipe is for the cheese sauce is 1/4 cup flour and 1/4 cup fat (usually butter but sometimes bacon grease if I have it). I will also throw some pepper in the hot oil before I add the flour to let it bloom. I cook the roux at a low temp because I read that can help with the texture. Cook that stirring continuously for about 5-10 mins. Then I add 2 cups of milk (usually skim) and stir that until it is smooth. Once that looks satisfactory I will add other spices and the cheese. When the dish is don’t I find the cheese sauce isn’t as smooth as I would like it and it seems like I added a bunch of small bread crumbs to it. Not ideal

A few notes. I find when I add milk that the roux turns into a big clump, then when I add more milk it smooths back out, not sure if that’s normal. I also don’t get a ton of colour on the roux before I add milk, usually just a cent darker than the milk.

If you have any solutions or suggestions to get the cheese sauce to a smooth consistency that would be appreciated.

I use sodium citrate. Google sodium citrate mac-n-cheese.

Are you shredding the cheese yourself, or using packaged shredded cheese?

I never do a roux for cheese sauce, I do heavy cream and water, American cheese and cheddar, plus whatever other cheese I want. I can dig up a recipe

This is the way.

Ingredients:
Heavy Cream: 220g
Water: 183.3g
Yellow American Cheese (grated): 220g
Havarti Cheese (grated): 137.5g
Provolone Cheese (grated): 82.5g
Kosher Salt: 1.6g
Fresh Ground White Pepper: ~1.3 turns
Procedures:
Combine cream and water in a pot, bring to a simmer then immediately turn down to 175°.
With the heat set at 175°, slowly add cheese, salt & pepper while blending with an immersion blender and blend for 30-35 minutes. Once time has elapsed, the temp of the fondue should be 125°-130° before it's done.
Cool to below 41° before storing.
For service, re-heat to above 165° before hot holding for service.

Your roux is too hot when you add the cheese, that is what gives it the gritty texture.

sodium citrate is the active ingredient that makes american cheese make creamy cheese sauces.

A slice of American cheese is usually enough. Two if you want it extra smooth.

Yeah, it's a cheat way to add it. I also like to use cream cheese

I swear by adding the first third or so of the milk a little bit at a time and stirring it thoroughly each time you add it.

Adding the cheese in batches can help, iirc.

You add the cheese like a quarter cup/handful at a time and stir until fully incorporated, then you add the next batch, rinse and repeat until all the cheese is added.

That, plus as some other commenters have mentioned, adding a slice of American cheese, a hunk of Velveeta or some sodium citrate can help get the sauce nice and perfect

More experienced chefs, please feel free to correct me if I'm wrong.

Cream cheese is another option I found