Plunger (10) for brewing a drink in a cup (12) includes two main components, a filter disc (20) and a frame (22). The filter disc (20) is shaped to extend across and abut an inside surface (24) of the cup (12). The frame (22) is dimensioned so that it can be wholly inserted into the cup (12) to be disposed below a mouth (18) of the cup. This allows a drink such as coffee or tea to be brewed in the cup from which it is to be consumed without the plunger (10) interfering with the drinking of the drink. The disc (20) is supported on the frame (22) to slide along upright posts (22). Thus the disc (20) can be pushed toward the bottom or (14) of the cup (12) that contain particulate materials such as coffee grounds or tea leaves used in brewing the drink. A heat shield (58) may be also supported on the frame (22) to minimise the rate of heat loss of a hot drink brewed in the cup (12) using the plunger (10).