The invention relates to a capsule (2), system and method for preparing a predetermined quantity of beverage suitable for consumption using an extractable product. The capsule comprises a circumferential first wall (14), a second wall (16) closing the circumferential first wall at a first end (18), and a flexible sheet-shaped perforate and/or porous third wall (20) closing the circumferential first wall at a second, open, end (22) opposite the second wall, wherein the first, second and third wall enclose an inner space (24) comprising the extractable product, wherein the third wall forms an outermost boundary of the capsule in an axial direction thereof, and wherein the third wall comprises a woven or nonwoven filtering material, such as filtering paper.