A dispensing system for a mouth defined by a target container, to permit a transfer of at least one contained substance into the target container, the dispensing system comprising: a dispensing adaptor for being reversibly and sealably mounted to the target container over the mouth, the dispensing adaptor having: a mounting portion for sealably communicating with the mouth of the target container, the mounting portion having an inner wall with a shoulder and a channel, an outer wall, and an upper edge for reversibly sealing against the mouth of the target container, an aperture, a connecting portion, a plurality of spaced-apart wings projecting inwardly from an outer periphery of the aperture to a central portion; and a Dispensable Containment Vessel, DCV, for being sealably connected to the dispensing adaptor, the DCV having: a connecting portion for sealably communicating with the dispensing adaptor, at least one reservoir for holding the contained substance, a resilient peripheral edge for sealing the DCV to the dispensing adaptor; a frangible barrier sealing the contained substance within the reservoir and having a plurality of tearing paths defining a plurality of flaps in the frangible barrier; the connecting portion of the dispensing adaptor for engaging the connecting portion of the DCV so that the resilient peripheral edge engages the shoulder in a secure conformation; the connecting portion of the dispensing adaptor engaging the connecting portion of the DCV so that the resilient peripheral edge engages the channel in a dispensing conformation; wherein a transition from the secure conformation to the dispensing conformation places the central portion and the plurality of spaced-apart wings against the barrier to frangibly tear the barrier along the tearing paths, generating the plurality of flaps and forcing the flaps apart, and the resilient peripheral edge engages the channel. a dispensing adaptor for being reversibly and sealably mounted to the target container over the mouth, the dispensing adaptor having: a mounting portion for sealably communicating with the mouth of the target container, the mounting portion having an inner wall with a shoulder and a channel, an outer wall, and an upper edge for reversibly sealing against the mouth of the target container, an aperture, a connecting portion, a plurality of spaced-apart wings projecting inwardly from an outer periphery of the aperture to a central portion; and a mounting portion for sealably communicating with the mouth of the target container, the mounting portion having an inner wall with a shoulder and a channel, an outer wall, and an upper edge for reversibly sealing against the mouth of the target container, an aperture, a connecting portion, a plurality of spaced-apart wings projecting inwardly from an outer periphery of the aperture to a central portion; and a Dispensable Containment Vessel, DCV, for being sealably connected to the dispensing adaptor, the DCV having: a connecting portion for sealably communicating with the dispensing adaptor, at least one reservoir for holding the contained substance, a resilient peripheral edge for sealing the DCV to the dispensing adaptor; a frangible barrier sealing the contained substance within the reservoir and having a plurality of tearing paths defining a plurality of flaps in the frangible barrier; a connecting portion for sealably communicating with the dispensing adaptor, at least one reservoir for holding the contained substance, a resilient peripheral edge for sealing the DCV to the dispensing adaptor; a frangible barrier sealing the contained substance within the reservoir and having a plurality of tearing paths defining a plurality of flaps in the frangible barrier; the connecting portion of the dispensing adaptor for engaging the connecting portion of the DCV so that the resilient peripheral edge engages the shoulder in a secure conformation; the connecting portion of the dispensing adaptor engaging the connecting portion of the DCV so that the resilient peripheral edge engages the channel in a dispensing conformation; wherein a transition from the secure conformation to the dispensing conformation places the central portion and the plurality of spaced-apart wings against the barrier to frangibly tear the barrier along the tearing paths, generating the plurality of flaps and forcing the flaps apart, and the resilient peripheral edge engages the channel.