Ask the Cook: What exactly is Parmesan cheese?
My recipe for fettuccine Alfredo calls for Parmigiano-Reggiano grated cheese. I could not find this at my grocery store, but they did have grated Parmesan Romano. Will that work?
Parmesan is a name that can cover a number of cheeses. Only cheese made in Italy can be called Parmigiano-Reggiano. Cheese made anywhere else, including America, is simply called Parmesan. Parmagiano-Reggiano is higher quality and usually will cost more.
Romano is the designation for a style of cheese that originated near Rome. The most common one found in America is Pecorino Romano. It's tangier and dryer, but will work in most recipes calling for a Parmesan-style cheese.
Whichever one you use, it's best to get a block of cheese and grate it yourself. It will have a fresher flavor and a better consistency for melting into a sauce. Pre-grated cheeses are often very dry.
Whatever you do, avoid the stuff in the green cans. It's like cheese-flavored sawdust.
— McClatchy Newspapers