Extraction and separation method of the must during the pressing of grapes in a pressing machine in a pressing process that occurs by means of the application of a pressure Pi on the grapes intended for the extraction of the must contained in it, in which there is provided the arrangement of a pH sensor means downstream with respect to said pressing machine intended to carry out a real time on line measuring of the pH of the product extracted from the pressing, said extraction and separation method of the must involving the intervention on said pressing machine and/or the deviation of the flow of said must on the basis of said real time on line measuring of the pH of the product extracted from the pressing.
