The economics of biogas plants have an impact on the justification of the industrial unit. The conditions of high-yielding high-quality biogas production are estimated on the basis of laboratory fermentation studies. In designing the laboratory fermenters, working conditions must be modelled. However, the biggest problem with the biological model is its size, because the magnitude is less than in industrial applications and therefore extremely sensitive to environmental influences. During the design, an important aspect is that the periodic mixing of the raw material can be done in the reactors as in the industry. This article shows the equipment based on empirical research.