The ability of the ropy slime-producing lactic acid bacteria to form ropy colonies aerobically and anaerobically on APT, MRS, MRS-S and Rogosa SL agars at 15, 20 and 30 degrees C was tested. Wide variation was observed in the proportion of ropy colonies produced with different culture methods and different test periods. The percentage of viscous colonies was usually highest at 15 degrees C. No suitable uniform method for all strains was found; and the results varied according to the bacterial strain studied. For testing purposes, use of the method producing the highest proportion of ropy colonies for each bacterial strain is recommended.