Like Appleman said, you must buy expensive filtering units to actually sterile filter wine. While the minijet and superjet have filters called "sterile," they cannot remove all yeast that might referment with resweetening or other beasties that might foul the wine. Why do you not want to use potassium sorbate? This ingrediant not only impedes refermentation, but also protects against bacterial infections. Edited by: dfwwino