Three operational variants based on 5 min long mixing of the fermenter content (75 L) with an agitator and then 20–40 min long cycles of its switching off were used to det. the effect of mixing method on biogas prodn. in a 12 days long process. The highest biogas „yield“ (35 L/day) was achieved for the variant with 40 min long cycle of the switched off agitator while the highest MeH content and lowest H2S content in the biogas (67.4% and 1564 ppm, resp.) were achieved for the variant with 20 min long cycle of the switched off agitator.