A capsule for use in a brewing device is provided, comprising a body part, which defines a cavity and which has a flange, a lid which is attached to the flange and tea material enclosed within the capsule, characterized in that the shape of the flange is defined by two intersecting circular arcs when viewed from above. A brewing device which comprises a capsule holder for receiving the capsule is also provided, the capsule holder comprising a sidewall which is circular when viewed from above and which has an upper rim, a shelf on at least part of the inside of the sidewall, a filter and an openable and closable passage on the opposite side of the filter from the upper rim. A method of preparing a tea-based beverage in the brewing device using the capsule is also provided.
