The milling process begins with a pre-cleaning of the grain when delivered to the mills. The grain is then stored in silos according to wheat type (one for each type of grain). The grain is subjected to a first cleaning along vertical and horizontal conveyors. Then the grain is tempered in the machines and the humidity is corrected to facilitate the subsequent separation of the bran from the endosperm. The grain is stored in silos to "rest" and then subjected to a second cleaning.
From here it goes directly to the milling cylinders.
The break rolls in the grinding room transform the grain into flour. The grinding room holds a series of machines in parallel rows. Each machine receives the ground grain of the machine before it.
The first operation is the break process. The grain arrives from the silos and is loaded into the first machine. Here it is "broken" by two steel cylinders furrowed by rows; the cylinders rotate in opposite directions. The ground grain falls onto an oscillating sieve which separates the largest fragments (bran) from the lighter ones, made of coarse flour mixed with bran: this reduction process is called sifting (i.e sieving). The process is repeated in the other machines, where the cylinders are always closer together and the grain becomes finer at each stage.
The process ends with a regrinding operation. The product of the above process is reground in machines with perfectly cylindrical rollers operating very closely together: this yields coarse flour (type 2), fine (type 1), very fine (type 0) and extremely fine (type 00). The sacks of flour are stored in a warehouse until delivery to the customer.