Why did my cheese sauce turn grainy?
Usually it is one of a few things: the sauce got too hot (a simmer is fine, but boiling is the fast track to grainy), the cheese went in too fast, or you used pre-shredded cheese with anti-caking agents. Also, very aged cheddar and some lower-fat cheeses can break more easily. Keep the heat low, add cheese off the heat, and shred your own if you can.
What cheese melts best for a creamy mac and cheese sauce?
Sharp cheddar for flavor and Monterey Jack for melt is a great combo. Mozzarella melts well too, but it can get a little stretchy if you stir aggressively. Gruyère is also excellent if you want a fancier vibe.
Can I make this sauce without flour?
Yes. Use cornstarch instead: whisk 1 1/2 tablespoons cornstarch with 2 tablespoons cold milk until smooth, then whisk it into the warm milk once it is in the pan. Simmer gently until it thickens, then add cheese off the heat. If you like a slightly thinner sauce, start with 1 tablespoon and add more only if needed.
How do I make it extra creamy for baked mac?
Make the sauce slightly looser than you think you need by adding an extra splash of milk. Pasta absorbs liquid in the oven, so a looser sauce going in means a creamier pan coming out. Also, slightly undercook the pasta by about 1 minute so it does not turn soft in the bake.
Can I use heavy cream?
Yes. Swap up to 1 cup of the milk for heavy cream for a richer sauce. Just keep the heat gentle so it does not scorch or boil.