Freshly milked milk was poured into special containers, of various shapes, designed to filter and collect any impurities present in it.
The filter was generally made from a single piece of wood and consisted of a round (or rectangular) tub, with a hole in the center and a splash guard, placed on a board that allowed it to rest on a container.
The hole in the center of the tub was blocked with various types of materials (straw, leaves, chestnut burrs, wool, etc.) arranged in such a way as not to impede the passage of the milk and allow the collection of impurities.