A double-chamber vessel for flowable substances having a lateral outer wall with a first chamber enclosed by a first, in particular transparent wall and a second chamber enclosed by a second transparent wall in which the first and second chambers each have an opening which openings end commonly in an opening section of the double-chamber vessel, otherwise they are completely separated from each other, wherein the first chamber is an inner chamber that is enclosed by the second chamber, which is an outer chamber, wherein in planar sections the first wall enclosing the first chamber lies directly against the second wall enclosing the second chamber, at the same time forming the lateral outer wall of the double-chamber vessel, or in the planar sections, the second wall forms the first wall and wherein both chambers have a continuous flow connection to the respective openings.