If you can keep it airtight in a jar, the juice supposedly will last a day. I guess that I figure that I go through the trouble to make it so I don't mind rinsing my juicer in the morning after a first glass (not "wash" but rinse and leave in sink) then I fire up a second batch in afternoon/p.m. That is, in a perfect world. I'm probably making 10 a week. I sometimes purchase them out (but I HATE adding yet another plastic cup to the area landfill and both local stores won't let me bring in my own container)
This weekly amount of juice; compounded with an alkalizing diet, has really helped my running injury.
leslie myers http://www.foodsensenow.com