A thousand stardates seem to be more or less a year, so it might have taken six years to ferment. Or then sixteen. Or twenty-six. Or one hundred and fifty-six. Note the absence of the "decade digit" in this 1000 SD = 1 y assumption, meaning that a 8300 stardate can very well be about fifteen years after "Space Seed"...
Were there a Romulan label on the bottle, Kirk couldn't read it, not even the date on it. The TOS heroes don't read alien languages all that fluently - Scotty and Chekov couldn't read Klingon in the following movie. No doubt the label is there for (illegal) export purposes.
As evidenced on the original series, the Stardates progressed without what seemed to be any consistancy. The earliest stardates on the series started with a 1, while by the end of the show, three years later, they started with a 6.
I thought the latest star date we saw was 5943.7 from All Our Yesterdays
Early in Season One the stardates started with a 1. Three years later would be early Season Four, when the stardates started with a 6.
And technically, the last stardate we saw was 5943.9.