The aim of this study was to investigate membrane filtration for must processing and to carry out a complex method for preservation and concentration of grape must. In the experiments white and red grape-juice samples were used. After the transportation of the samples in to the laboratory the impact of the pre-treatment and process parameters were examined, and in the case of red grape must also the degree of anthocyanin retention was measured as well. Microfiltration (MF) resulted in the clarification and sterilization of the samples. After microfiltration permeates were concentrated by reverse osmosis (RO). During filtration the sugar content remained in the retentate. Very low anthocyanin content was measured in the red grape juice permeate, which proves good anthocyanin retention of the membrane. With the combination of the two processes a new complex method can be established that results in a sterile concentrate with a higher sugar content. This method gives a possibility to handle must excess and to develop a new product without preservatives.