The liquid milk trade was very restricted before the late 19th century: in the dairy, milk was converted to butter and cheese - products with much better keeping qualities. The dairy on a small farm was often within the farmhouse in a rear room. Some were separate buildings but, as the women of the household managed the dairy, they were normally close to the house. The dairy needed to be cool and well ventilated, so it was usually situated to the north of the house, shaded by trees and partly sunk into the ground. It had thick, cool flagstones on the floor and thick stone shelves on which the dairy produce was stored. Windows were shuttered, not glazed.