"Formaggio di fossa" (literally "pit cheese") is a typical Italian cheese produced in the area between Emilia-Romagna and Marche regions (specifically the entire territory of the following provinces: Forlì-Cesena, Rimini, Ravenna, Pesaro-Urbino, Ancona, Macerata, Ascoli-Piceno; and part of the province of Bologna), obtained by the fermentation of sheep (or partially mixed with cow milk) cheese in natural underground pits.
The pits were carved out of the tufa rock, depth about 3 meters. Few days before, straw is burned to reduce the accumulated humidity; the various forms of cheese, wrapped in cotton cloth, are placed in the straw lined holes, next to each other, reaching the mouth of the pit. Finally it is closed with wooden planks and sand.
The storing in a pit of the forms of cheese takes place in August, and they will be there until November 25th (coinciding with the feast of St. Catherine). During the fermentation, the cheese takes a particular aroma of wood, truffle and musk and a unique sweet/spicy flavor. It has a golden hue and a crumbly texture.
The formaggio di fossa of Sogliano al Rubicone and Talamello got the PDO (Protected Designation of Origin) in 2009.
The custom to hid the forms of cheese in underground pits dates back to the Middle Ages, when local peasants had to save their food supplies from thieves and soldiers.