An interesting question.
I haven't noticed the aging process ending. I do a lot of nectar making. After a while. the nectar you make is of such high quality that, for me, it seems pointless to horde the low value stuff and I use it up, Sims love drinking nectar, at parties, or just as a daily tonic. I often use transfiguration to get a really high value storage rack full, but, I have noticed that these do not have the same percentage rate of improvement that can be achieved with home made perfect nectar. I colour code my nectar racks. Gold for the rediculously high value transfiguration bottles. Red for my best recipe perfect bottles and green for the almost as good nectar I make with lifefruit, flame fruit and pomegranate which I get my sims to drink on a daily basis because it gives them a great boost and extends their life one day for each glass drank. The rest gets used at parties, or sold on consignment.