During ceremonies, particularly those marking major milestones in life, the Zulu drink sorghum beer (utshwala) in the company of ancestors. Even though the colonial authorities prohibited the practice, at the turn of the twentieth century the production of beer pots increased, as the natural disasters and stresses of colonialism of the time prompted the Zulu to seek the aid of their ancestors. The surface of the pot is black in order to attract the ancestors, as that is their favourite colour. As for the designs known as amasumpa, they provide a better grip and might well also refer to female fertility. Moreover, both the beer and the pots are made by women.