Collapsing beer foam produces a liquid and a suspended precipitate. Both the collapsed foam-liquid and foam-precipitate were obtained from unhopped beer and from unhopped beer plus reduced isohumulone. A dual-column gel chromatographic method was used to separate the foam fractions. The resulting molecular weight distribution of the proteins was examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Isoelectricfocusing was also used to further resolve collected peaks. Characteristic profiles and differences in various foam components are presented. Evidence suggests the existence of an isohumulone-protein complex in the foam precipitate.