Cheese made from whole cows' milk coming from traditional cow breeds of the area, possibly with the addition of not more than 10% goats' milk, with medium to long ageing, having an even, concave cylindrical shape with flat faces and a sharp-edged rim. The outside has a straw-yellow colour, which tends to becomes more intense with ageing. The cheese is produced using traditional methods, connected with the environmental characteristics, during the period between June 1 and September 30.

Geographical Area: The entire province of Sondrio and the areas bordering the following Communes of the Alta Valle Brembana in the province of Bergamo: Averara, Carona, Cusió, Foppolo, Mezzoldo, Piazzatorre, Santa Brigida and Valleve. These define an area with particular environmental characteristics.

The raising of livestock and, as a consequence, the making of cheese, has always been an important factor in the economy of the

Valtellina. The presence of extensive pastures has brought about a seasonal migration in the traditional production area, from the highest elevations in the spring and summer to intermediate elevations in the fall. In particular, over time the cheeses from the Alps have been differentiated into distinct, characteristic types, which are a product of the natural mountain resources, handed down through local traditions over the centuries. The name Bitto appears to be derived from an ancient Celtic word for a type of Alpine cheese coming from the valley of the same name. In more recent times, Bitto cheese has become well known in local markets, which show the maintaining of a particular cheese-making process, which is currently recognized under Italian law by a special decree which defines the requisites for the designation of origin.

After the coagulating of the milk with calf rennet, making use of the spontaneous development of cheese microflora, the curd is heated and broken into lumps roughly the size of a grain of rice. The curd is then placed in traditional cheese moulds which give it its characteristic concave shape. After salting, the cheese undergoes the ripening stage, which begins in the traditional "casere d'alpe" rooms and is completed in the production plants down in the valley, following the natural march of the climate in the production area, for a minimum of 70 days, which may be followed by an additional period of ageing lasting up to several years. The natural factors are connected with the environmental conditions of the production area, which bring about a more or less even climate, favourable for the growth of certain types of vegetation. Livestock raising takes place in this area, using the natural pastures or local crops for feeding the animals, which provide the raw material to be processed. Thus it follows that the cheese is the result of a number of