Jugs were very common in every house in the Middle Ages. They were used to carry and pour drinks like wine and ale and to carry water for cooking and cleaning.This type of jug is called a baluster jug, because it is shaped like a baluster in a balustrade. If you look closely you can see that the potter has added small rosettes to the body of the pot. The green colour was created by adding ground up copper to the lead glaze.