Beers entering filtration often contain large quantities of yeast, making kieselguhr filtration difficult. Kieselguhr filtration itself is not problem-free. Means are available either to replace the kieselguhr filtration or at least to reduce the consumption of kieselguhr. By employing a separator to pre-clarify the beer, the required degree of filtering can be drastically reduced. The result is not only a reduction of a filter aid, but also an increased period of operation. Of course, the centrifuges are also suitable for pre-clarifying with other filter systems.