How do you determine if pecorino is young or old?

A young pecorino is paler and softer in texture, with a milder, rounder flavor. An aged pecorino is harder and often more burnished in color, with a sharper, saltier flavor. Older pecorinos are aged over 6 months, and their labels will often say so.

Pretty sure aged Pecorino is harder and more crumbly than a young one - also a sharper/saltier taste. Kind of deeper color too. (When in doubt, I'd just ask your cheese guy. And ask for a taste.)

I'm answering mostly to thank you for calling attention to this recipe. The season has come around again and I'll be making this.

To answer your question: I don't know, but suggest a good cheese shop or department where someone will know. Is that acceptable?