Cooking

Parmesan, in particular, is a really hard cheese to emulsify, mainly just cause it's dry. "Traditional" Alfredo (as in from the original restaurant that gave it it's name), was made with young parmesan. To be parmesan (well, Parmigiano Reggiano), it has to be aged at least 12 months, but at least where I live, it's usually sold aged at least 24 months. This means drier, and even more difficult to emulsify.

If you can get really young parm, use that, and also make sure to grate it really finely. I often get lazy and grate it on my box grater, and it won't work well. It only works well if I use a microplane.

If you care about traditional ingredients, but not methodology, you can pull some pasta water off to the side, and keep it hot, but not boiling, and stir in the parmesan bit by bit. It helps greatly if you add sodium citrate to the water before adding the cheese. After the cheese has turned into a sauce, you can throw in some butter.

Parmesan doesnt really "melt" since it is too low moisture. To make a sauce, you are basically trying to dissolve the proteins into a liquid, which takes some time, and you can't rush it by cranking up the heat.

This is like a really bastardized? (I can't think of a better word, it's too harsh) cross between cacio e pepe and buttered noodles? Basically the sauce broke.

Maybe it lost too much heat. You may also need more starch? How much water did you use when cooking the pasta.

Also the way it glooped up feels like the cheese melted before actually being emulsified.

I've never heard of it being made with pasta water, but with the traditional Cream / Parmesan / Butter recipe, I cook it in a wide saute pan or skillet (12+ inches).

The other thing is that I use grated, not shredded Parmesan. If I only have shredded, I put it in the food processor for a couple of minutes to crumble it.

I start with the butter and cream, and bring it to a simmer and stir to melt the butter. Then add the Parmesan and stir for 30 - 60 seconds until it starts to melt, then add the cooked pasta to the pan and stir to coat.

I think this works well because the pan is shallow, so it cooks quickly. It's also the way I was taught in a restaurant I worked at many years ago, and we made it to order, and had variations (chicken / shrimp / primavera) where the ingredients were cooked in butter in the pan first, then the alfredo was built in the pan on top of whatever was there.

I know nothing about this method, and maybe the other answers will solve it. My question is: what kind of parmesan does this call for? I always grate mine fresh, and sometimes a recipe doesn't quite turn out because the author intended you to use the shelf-stable canister stuff.

Poor Alfredo, noone asked him if he wanted to be emulsified :(

Not a pro, but I usually add cheese off the heat because too much heat can make it separate into squishy gloops and watery whey.

I usually cheat a bit and make the sauce separately in a small pot on low heat. Still using just the traditional ingredients - cheese, butter, pasta water and then toss the pasta in the sauce. Not as showy as tossing all the ingredients together directly with the pasta, but I'm not trying to impress anyone and it's a little less picky about technique and needing to work quickly while the pasta is hot enough to melt it all together.

How much pasta water did you add before you started putting the cheese in?