The present invention is in the field of the preparation of lactic acid by means of fermentation, more particularly it is directed to processes to separate the biomass from the lactic acid-containing fermentation product by means of flocculation.We have found that for the separation of biomass from lactate and lactic acid-containing fermentation broth the following process is very convenient and suitable; a) Subjecting the fermentation broth to an alkalifying step, b) adding one or more flocculants, and c) separating the biomass flocs from the lactate and lactic acid-containing fermentation broth. With this process even bacteria-based fermentation broths can be suitably handled efficiently and economically.