Cheryl > wrote:

> I'm making Potatoes au Gratin and wanted Parmigiano Reggiano but my
> block is so hard that I didn't want to spend time grating it so picked
> up an already grated container from the deli but it wasn't Parmigiano
> Reggiano when I got home, it was Pecorino Romano. How different is this?

I do not quite understand... the harder the cheese, the easier it is to
grate, usually... How do you grate it? Perhaps getting a different
grater would make a difference?

Pecorino Romano is a particular kind of hard sheep's milk cheese
("pecorino" means sheep's cheese), typically matured for 8 months;
Parmigiano Reggiano is hard cow's milk cheese, matured for years.
Further differences between them can be numerous (and potentially
important), depending on their handling and their age. In their
more-or-less "generic" young state, as offered in my local supermarkets
(and perhaps yours), for example, I'd say that the taste of pecorino
romano is different in more ways than one, but particularly more
assertive and saltier than that of Parmigiano. Commercial grated
versions of either cheese tend to be inferior.

Depending on how you make your potato gratin, the difference can be
noticeable or not. It really is a matter of a particular recipe,
particular ingredients and personal preferences.

Victor