The French Pyrenean semi-hard sheep’s-milk cheese often used in gratins is Ossau-Iraty.
Ossau-Iraty is produced in southwestern France, across the French Basque Country and Béarn. Its name joins two geographic references: the Ossau Valley in Béarn and the Irati Forest in the Basque Country. The cheese has a firm, smooth body that can range from white to cream as it matures, with a rind ranging from yellow-orange to gray.
The cheese has ancient pastoral roots and was traditionally made by shepherds using milk from local dairy sheep. Modern protected production permits milk from Basco-Béarnaise, Red-Faced Manech, and Black-Faced Manech breeds. Ossau-Iraty received French AOC recognition in 1980 and is protected today under the PDO system.
Its nutty, savory flavor makes it suitable for eating on a cheese board as well as melting into dishes such as gratins. It is easy to confuse with Roquefort because both are French sheep’s-milk cheeses, but Roquefort is a blue cheese, while Ossau-Iraty is an uncooked, pressed cheese with a compact texture.