The effect of blending polyglycols (F150 and DF250) with alcohols (MIBC and pentanol) on bubble size, gas holdup and froth height in a two-phase system has been determined. A synergistic effect on froth height was observed accompanied by a change in bubble size: below the alcohol critical coalescence concentration (CCC) the addition of small amounts of polyglycol decreased bubble size and, unexpectedly, above the alcohol CCC the polyglycol increased bubble size. Gas holdup confirmed the bubble size response. No explanation of the latter effect is immediately apparent. Implications for possible independent control of froth stability and bubble size as a reason for using frother blends are discussed. (C) 2013 Elsevier B.V. All rights reserved.