The grapes were then tipped onto the treading floor (forum vinarium) and crushed by bare-footed workmen who walked back and forth, sometimes leaning on one another, sometimes keeping their balance by holding onto a overhead beam. The new wine (mustum) flowed away from the floor through a stone channel that connected to a vat with a jar recessed into its floor, to collect dregs carried along by the wine's flow. Then the mustum slowly poured through clay pipes that led into two deeper settling-vats (lacus musti), each of which also had a dregs-gathering jar recessed into it.
The owner of each batch of mustum-we assume that as large a press as this one may have served more than one vineyard-will have been responsible for decanting it into the large jars (dolia) where the primary fermentation would take place over the subsequent weeks. Wine produced in this way was the kind drunk in most middle-class Roman homes.