That’s why it makes a difference.
The energy that makes the millstones move is obtained with the sole force of the water that slides into the wooden duct above the water wheels and makes them turn.
The energy produced causes the stone millstones inside the mill to act and begin to grind the seeds, until they turn into flour.
The seeds are introduced into the structure by large wooden containers, called hoppers, which make them slide into the small space existing between the heavy stones of the grinder, placed on each other. The millimetric space between the two means that the seed is not absolutely split or crushed, as it happens in industrial processing, but only deprived of the first layer; in this way the flour obtained keeps intact all the nutritional characteristics of the cereal.
After some processing cycles the surface of the stone must be revived to ensure that the grinding is always perfect. For this reason, the miller, milking himself a hammer and a lot of patience, carries out a procedure called hammering or rabbiting of the stone, which consists in practicing on its surface some rows at a distance of about 2/3 millimeters from each other.
As it's easy to guess, it's a long and tiring work, but necessary to keep the structure fully functional.