Parmigiano Reggiano PDO can only be made in a small zone around Parma, Reggio Emilia, Modena and parts of Bologna and Mantua, from raw milk, no additives, aged at least 12 months. Every wheel is pin-dotted and fire-branded with its name — a guarantee stretching back some eight centuries.
The imitation is generic ‘parmesan’: powdered, cheaper cow's cheese made anywhere from Wisconsin to Poland. Only the branded rind reads Parmigiano Reggiano, and only that is the real king of cheeses.