Colloidal gas aphrons (CGAs) were first reported by Sebba (J. Collozd Interface Sci., 35 (4) (1971) 643) as micro bubbles ( 10-100 /xm), composed of a gaseous inner core surrounded by a thin surfactant film, which are created by mtense sumng of a surfactant solution. Since then, these colloidal dispersions have been used for diverse applicatmns (clarification of suspensions, removal of sulphur crystals, separation of organic dyes from wastewater, etc.). However, there have been no reports, as yet, of their direct applicatton for protein recovery. In this study, CGAs are created from an anionic surfactant (AOT) and are charactensed m terms of stability and gas hold-up for a range of process parameters relevant to their proposed use for protein recovery, at a later stage. A statistical experimental design was developed in order to study the effect of different factors (surfactant concentratton, salt concentration, pH, time of stirring and temperature) on the staNhty and gas hold-up of CGAs. The analysis of results from the experimental design prowdes predictive statistical models Stab111ty was found to depend mainly on salt and surfactant concentration. Several interactions are shown to be mgmficant including the time-temperature interaction. Gas hold-up was found to depend mainly on salt and surfactant concentratmn and time of stirring. Also, results from power measurements are presented and the minimum energy for the formatton of CGAs, for one set of solution properties, ~s determined