The present invention is directed to flexible or semi-flexible closed package (1) for containing an ingredient for preparing an edible product in a food or beverage preparation machine, said package comprising: (i) flexible or semi-flexible lateral walls (2) that form a flatten package body, and (ii) a cup-shaped bottom portion (3) adapted to the insertion of a fluid injection element of the machine, the package (1) being formed from a one-piece elongated primary flat blank sheet (5) made of flexible material, that is folded in a U-shape around its transversal symmetry axis (Lx), and sealed along its lateral (4) and upper (34) edges, wherein said cup-shaped bottom portion (3) is a hollow volume having a concave lower side (7) and convex lateral sides (8), and the profile curvature of said lower side (7) being identical to the profile curvature of each of said lateral sides (8).