Capsule for preparing an edible product on a brewing device , and presenting: - a first construction element configured in a container-like form and adapted so as to provide a collection volume for a single portion of an edible substance, and - a second construction element configured in a circular lid-like form, and adapted so as to confine said collection volume of first construction element and as to provide an entry flow passageway to the interior of said first construction element , whereby said second construction element comprises a flow entry wall part that presents a disk-like general with a prevailing wall thickness (e 31 ) between two plane transversal relative to an axial axis (X) of said wall part , whereby said flow entry wall part is provided in a rigid material, whereby said flow entry wall part comprises a passageway region provided with a circular shape delimited by a first circumferential alignment and disposed centred relative to an axial axis (X) of said capsule , whereby said passageway wall presents a weakened material region that develops along at least most part of said first circumferential alignment and that is adapted so that breaks under a given upstream flow pressure, said capsule being characterized in that said flow passageway wall presents one, preferentially only a single one, projection element provided in asymmetric manner on said flow entry wall part and that develops upstream in the axial direction, whereby said projection element develops along an extension beyond the plane defined by the upstream oriented surface of said flow entry wall part , so that said projection element can be impinged by a flow injection part of said brewing device and thereby exert a lever-like mechanic force upon said weakened material region . - a first construction element configured in a container-like form and adapted so as to provide a collection volume for a single portion of an edible substance, and - a second construction element configured in a circular lid-like form, and adapted so as to confine said collection volume of first construction element and as to provide an entry flow passageway to the interior of said first construction element , whereby said second construction element comprises a flow entry wall part that presents a disk-like general with a prevailing wall thickness (e 31 ) between two plane transversal relative to an axial axis (X) of said wall part , whereby said flow entry wall part is provided in a rigid material, whereby said flow entry wall part comprises a passageway region provided with a circular shape delimited by a first circumferential alignment and disposed centred relative to an axial axis (X) of said capsule , whereby said passageway wall presents a weakened material region that develops along at least most part of said first circumferential alignment and that is adapted so that breaks under a given upstream flow pressure, said capsule being characterized in that said flow passageway wall presents one, preferentially only a single one, projection element provided in asymmetric manner on said flow entry wall part and that develops upstream in the axial direction, whereby said projection element develops along an extension beyond the plane defined by the upstream oriented surface of said flow entry wall part , so that said projection element can be impinged by a flow injection part of said brewing device and thereby exert a lever-like mechanic force upon said weakened material region . <EOS>