The emulsifier isolated by extraction of Saccharomyces cerevisiae biomass was resolved into two major components. One component contains mainly protein and some carbohydrate. This appears to be the protein backbone of the phosphomannoprotein of the yeast cell wall. This component was even more effective than the original product obtained from the yeast biomass. Consistent with its properties as an emulsifier, it partitioned strongly to the interface between the water and oil phases of an emulsion. The other component contained abundant carbohydrate and phosphorous and was attributed to the phosphomannan fragments from the original cell wall material. It does not appear to be an emulsifier, but it enhanced the emulsification properties of the first component. It was very water soluble, and most of it remained in the aqueous phase when an emulsion was prepared.