In mid-August, before each cheese is tied in a burlap sack and placed in fossas dug in the porous ground (tufo), they are disinfected with fire and lined with hay. The fossas are flask shaped, about three meters deep and two meters wide. Each sack is marked with the owners' name and stacked in layers on planks of wood and separated by sand. They are packed close together so no air can get in. The fossa is then hermetically sealed. Over the months they have undergone a total re-fermentation, losing practically all the whey. On November 16th this revered cheese is "harvested" during the holiday of Santa Caterina. The cheese is pulled from the ground, cleaned, wrapped in it's characteristic rustic brown paper, secured with a string and sold during the festivities by some, while others jealously cling to their formaggio.
Fossa has an intense and somewhat piquant flavor that makes it excellent as a table cheese with fresh fruit and honey, or grated over pasta or risotto.