There is confusion in the literature concerning whether the proteins primarily responsible for foam stability consist of a few, specific species (such as protein Z and Lipid Transfer Protein) or whether the contribution of polypeptides to foam stability is relatively non-specific and is a function of a protein's inherent physical properties, most notably its amphipathic character. Previous work had suggested that the levels of foaming polypeptides increase during malting, and furthermore that the foaming polypeptides in beer derive from the hordein component of barley. In our investigation, we have extracted the hordein and albumin fractions from barley and have assessed their inherent foaming properties, both before and after proteolytic digestion using a range of proteinases to simulate the hydrolysis encountered during malting and mashing. We have employed a new technique, not yet applied in this context, for the assessment of hydrophobicity of the polypeptides. Hydrolysis of both hordeins and albumins resulted in a net increase in hydrophobic character, accompanied by an increase in their foam stabilizing capability. Excessive proteolysis led to a diminution in foam stability. Both protein fractions had the ability to generate a foam, while the foam stabilizing capability derived from the hordein fraction considerably exceeds that from the albumin portion.