@benhamill@cybre.space it's not quite the same thing, but you might consider looking at shrub (drink) recipes - a type of fruit vinegar that you'd then use as a syrup to make a drink similar to lemonade, really popular in colonial america era thereabouts

also relishes! after all, sauerkraut is just fermented cabbage relish. there are very likely other fermented/pickled relish recipes using fruit out there! chow chow might be a good stepping stone there, since it's primarily green tomato based.