Grana Padano PDO cheese is made exclusively from raw milk coming from the production area specified by regulations. The milk is obtained from no more than two milkings per day and is partially skimmed by natural surfacing. The cows are fed in compliance with strict rules and their milk is processed exclusively in copper, upside down bell shaped kettles, from each of which two wheels are obtained. In the kettle, natural whey is added to the milk, which is then heated to 31-33 ° C and added with calf rennet for coagulation. Afterwards, the curd gets broken using a tool called “spino”, then cooked up to 53-56 °C while being stirred. The cheese mass settles down on the bottom of the kettle and rests for no longer than 70 minutes, to solidify and drain the whey. Finally, the cheese-makers lift the mass inside the kettle using a wooden shovel and a piece of fabric (called “schiavino”). They then cut the mass into two halves, or “twin wheels”. Each wheel is wrapped up in a piece of linen, removed from the kettle and placed on the sink. After about 24 hours, the first mold is replaced with a steel one, pitted with tiny holes and slightly rounded, which in about a day will give the cheese its final, characteristic shape: with convex vertical sides and flat faces. At this point, the cheese is ready to be salted, so it is brined for a period ranging from 14 to 30 days. After drying in a specific room (called “hot room” or “stewing room”), the seasoning process begins. It lasts from a minimum of 9 to over 20 months, in well-insulated rooms, equipped with cutting-edge temperature, humidity and ventilation control systems. Over the course of the long seasoning, Grana Padano cheese undergoes a series of chemical-physical and microbiological changes which can be seen in its organoleptic properties. The wheels are attended, cleaned and turned around every 15 days. These tasks, which used to be carried out entirely by hand, are now mechanized thanks to efficient brushing and turning machines.