Hi Karyn
Little work has been done on how long it stays viable but technique explained on link. Worth trying and see if any is viable next year.
Pollen is beautiful stuff see http://www.passionflow.co.uk/passion-flower-passiflora-pollen-sem.htm

Here is a link that might be useful: Pollen storage

Thanks for the storage link. I might as well try it and see if it's still viable next season. The worst that will happen is it won't work. Actually I still have a Leitz research microscope from my grad school days that I occasionally use and have viewed pollen. It's nothing like looking through an electron microscope but is still very cool.
Karyn