Wash ripe pomegranates. Submerge in a large bowl or tub of water. Cut open and with your fingers pry out the seeds. They will fall to the bottom of the bucket while the pith will rise to the top.
Scoop off and discard pith, drain all the water, then re-rinse seeds, drain well..
Using your hands, squeeze the seeds to extract the juice. Strain through damp cheesecloth, squeezing well.
Make a simple syrup by boiling water and sugar 1:1. Let cool.
Fill a clean bottle half way with juice. Add 1/8-1/4 syrup and the rest vodka. Shake and taste. Add more juice, syrup or vodka to balance flavor. It should be sweet, tart and juicy with a slight alcohol kick.
Seal and refrigerate a few days to mellow the flavors. Serve in cordial glasses, well chilled, or mix with Prosecco, champagne or white wine.