Using the plastic around the top of a mason jar sounds like a great solution for storing juice in good condition. I am also glad to hear some confirmation that vacuum sealing is a good idea for storing juice. I have since found a couple of studies backing up the idea of vacuum sealing as a sound way to enhance the quality of stored juice. Enzyme activity seems to be the key measurement, and the studies do seem to bear out the quality can remain high for a number of days if one uses a juicer that does not cause the enzymes to perish. Taking advantage of my vacuum sealer for mason jars makes sense.