Good post, Choir Loft.
As a protestant... Presbyterian... I have not problem with fermented grapes.
Although, my paternal Grandparents did.
That was, primarily as I believe, because my grandpap's dad was an alcoholic. ( And had such a horrible skeleton in his closet, that I laugh about, through my shame... though it did not affect me.... ( maybe mentally) ... but he was a bigamist.)(And most likly why grandpap would never drink, as he likely blamed the booze on the 2 wives.) (BTW... this was only discovered this past year when I was doing genealogy, it was never known in the family)
They, the grandfolks, were such teetotalers that my grandmother would not even use things like real vanilla in her cooking and baking.
And she also canned her own grape juice, every year.
When grandpap died, under Doctors orders, she had to take a tablespoon or so of scotch before bed to help her sleep. She did this for a few days only, and then carefully placed the remainder of the bottle in the corner of the china cabinet.
It would have been "wrong" to just pour something out...


?
Anyway, 30 some odd years later, when grandma, herself, died..... in cleaning out her apartment, the bottle of scotch was still there. ( My aunt's husband quickly laid claims to it)
But the funniest grapefruit story I know was from anold boss of mine.
Seems he had , I think it was an aunt, who was also a true teetotaler.....
And, like grandma, she also canned grapejuice every year.
Every weekend through the summer the family would go visiting just to have her wonderful juice... and she was so complimented that they
like it so much.
But her grape juice always managed to ferment..... and her family was coming to get a little high.

She never knew it ever fermented, she thought that was the way grape juice was supposed to taste.