The invention is directed to a process for preparing a juice product from a raw juice feed comprising microorganisms by subjecting the raw juice feed to microfiltration to obtain the juice product and a retentate juice product, wherein the microfiltration is performed as a cross-flow filtration over a sieve, which sieve has openings that are smaller than the dimensions of the microorganisms present in the raw juice feed and wherein over the sieve a high frequency back pulsing is applied.