In the seventeenth and early eighteenth centuries posset was both a drink and a comforting remedy for minor ailments. It was made from warm milk curdled with ale or wine and flavoured with sugar and spices. Posset pots could be made of pewter, silver, earthenware or, from the last quarter of the seventeenth century, glass. They usually had two handles and a cover, and some had a spout through which the posset was sucked or poured. The earliest recorded delftware pot, dated 1631 (Fitzwilliam Museum, 0.1294–1928), has straight sides and an almost flat cover. Pots with curved sides had been introduced by the 1650s and, judging by dated examples, predominated by the 1680s.

The importance of posset at social gatherings is indicated by the elaborate forms of the largest pots of the 1680s and 1690s. Their handles and covers were decorated with curlicues and serpents and the covers often had a finial in the shape of a bird perching on a globe. To complement this, some pots had bird-shaped feet. A little later, about 1699–1705, covers shaped like crowns were fashionable. These large pots are usually decorated with flowers, European scenes or Chinese figures in landscapes derived from late Ming porcelain. Smaller pots may be similarly decorated, but they and the larger types are often plain except for a coat of arms or a cartouche containing the owner's initials.