I've tried making Cacio e Pepe a few times, using a recipe from America's Test Kitchen. In Cacio e Pepe, you boil pasta in a limited amount of water, then mix some of the hot starchy water with grated pecorino Romano cheese. The cheese melts/dissolves in the water to form a cheesy liquid which is poured over the pasta.
I've had good luck doing this with Romano, even using domestic cow's milk Romano. But one time I was short on Romano, and tried using about 1/4th Romano and 3/4ths imported Parmesan. When I added the starchy water, some of the cheese dissolved–the Romano, I assume–but most of it coagulated into a gooey, stretchy mass.
What is the difference between Romano and Parmesan, that would make them behave so differently when mixed with hot, starchy water? Are there other similar cheeses–asiago for example–that would work well in this recipe?
Best Answer
Pecorino Romano is a heavily salted, aged cheese. As a result, it tends not to "melt", just as feta, haloumi, and queso fresco tend not to melt (all are also heavily salted cheeses). Presumably mizithra or ricotta salata would work equally well in the ATK recipe, although they wouldn't taste the same.
If you inadvertently purchase a different kind of pecorino (sardo, for example), or even a fairly young pecorino romano, you'll find that you have the "gooey mess" problem with that procedure.
Now, a comment: the ATK recipe for Cacio e Pepe sounds bizarre to say the least. The normal way of making Cacio e Pepe is:
If you follow the traditional recipe, then you can use a wider variety of grating cheeses without worrying about it becoming a gooey mass.