Castelmagno is a semi-hard, crumbly cow's-milk cheese from the high Grana and Stura valleys of Piedmont, in the far north-west of Italy, protected since 1996 with DOP (PDO) status. Its pressed white paste is sharp, salty and lactic when young, growing nutty, savoury and faintly bitter with age; older wheels develop a natural blue-green veining that lends a gentle piquancy. It is the classic Piedmontese table cheese — melted into risotto and gnocchi, and famously eaten with a drizzle of honey.