Does one pan for brass? (6)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

Cryptic definition: we’re talking about someone who is paid to write reviews of books, theatre, etc. Pan, as a verb = to criticise strongly (for example, to write a one-star or zero-star review); for brass = for money. (The surface suggests panning for gold = using a shallow metal pan to inspect river water for tiny pieces of gold.)