Comparison of yeast and mold counts by spiral, pour, and streak plate methods.

Foods with naturally occurring yeast and mold were used in a comparative study of 4 plating techniques. Oats, green beans, and cheese were incubated for 3 and 5 days at 25 degrees C. Although 3 days of incubation would be sufficient for yeast, 5 days were necessary for the mold count. The percent recovery of yeast and molds by the spiral and streak methods ranged from 200 to 357% compared with the pour plating method described in the Bacteriological Analytical manual (BAM). The spiral method had the highest overall recovery and the lowest replicate plating error.