My neighbour buys grapes, presses them (not trampling), and puts them into demijohns with an airlock. He adds nothing. It ferments using yeast on the grapes over several months. Over the course of a year, he decants from one demijohn to the next, which clarifies yeast, then he bottles and lets it rest some more. It’s in a cool part of the house, about 14-18C.

It’s very tasty wine, but doesn’t have any oak overtones or adjuncts (whether lead or vanillin or whatever else is added), it’s not blended, and it’s moderate abv (around 10%).

This process requires very little in terms of specific materials other than the glass instead of clay. Clay vessels, being porous, would alter the flavour and would harbour yeasties and other microorganisms. But even accounting for that, I don’t think there’s any basis to say ancient wine would be dogshit. It may be different, accounting for taste, but not bad. (Consider the popularity of sour beers (kettle sours or otherwise) and hazy beers. Both of those were considered highly undesirable properties of beer for most of the 20th century - so tastes change. )