The origin of Grana Padano cheese is disputed between Lodi and Codogno. However, from this limited area it has spread in the whole Po valley, and therefore also in the area of Oglio, maintaining almost unchanged its features and taste over the centuries. Grana Padano cheese is a cheese with cooked dough produced with cow's milk obtained from two milking stages, partially skimmed through surfacing. The maturation period lasts from 8 to 24 months and the cylindrical rounds have an average weight of about 35 kilos. The rind is hard, smooth, and thick, dark yellow; the straw-yellow color dough presents the characteristic granulosity, has no holes and, under the pressure of the blade, it breaks into flakes. The aroma is fragrant, the taste is clean, but at the same time delicate, never spicy. Mainly used as grated cheese, it is also ideal to taste in flakes. In 1955 Grana Padano obtained the Designation of Origin, wit the Po Plain as its exclusive production area. Since 1957, Consorzio di Tutela Grana Padano has been implementing safeguard activities and promoting technical research for the continuous improvement of quality. In 1996, with the Regulation CE n.1107/96, it obtained the PDO label with the approval of regulations specifying its production area, maturation method, and processing technology.