Abstract Tarhana is a fermented wheat flour–yoghurt mixture which is widely consumed in Turkey. Baker's yeast is also involved in the fermentation. In this study, fermentation activity of tarhana was investigated by monitoring the lactic acid bacteria and yeast population when the level of salt and amount of yoghurt used were varied. Fermentation activity was high during the first day of fermentation. Microbial counts dropped below the initial counts at the end of a 4-day fermentation. Fermentation activity of tarhana prepared without salt was found to be higher than the tarhana samples prepared with salt.