A capsule for preparing a predetermined quantity of beverage with a beverage brewing device is disclosed. The beverage brewing device comprises a receptacle for receiving the capsule. The capsule comprises a cup comprising a circumferential wall, a bottom closing the circumferential wall at a first end, and a lid in use connected to the cup at a second end of the circumferential wall opposite the bottom. The wall, bottom and lid, in use, enclose an inner space comprising the extractable product. At least a portion of a surface of the capsule conceived to, in use, interact with the receptacle is provided with at least one projection for forming a sealing engagement with the receptacle.