I used to make wine.... as much as I love the stuff, you cannot make it onboard. Between temperature differentials, motion, aging, it just isn't worth it.
Some thoughts on alcohol on board (which is a priority for us):
1) Distilling liquor and then making it into various other things. Stills are a couple hundred bucks, and the process takes 5 days or so in a bucket. Getting one for our boat
for sure... Check out the Delos crew make the stuff in this vid:
2) We love prosecco.... instead of having lots of glass bottles on board, we have a good supplier of white wine in boxes. It keeps forever even open, unbreakable, and we can store a ton in the bilges. Then enter Sodastream, and fizz it up. Works like a charm.
3) Maybe try beer
making? Anything will be easier than making decent wine....