Unfortunately it's extremely difficult for modern historians to really figure out what ancient wine was like. While the general process of making Roman wine is very similar to how it's made today apart from the storage containers not including stuff like stainless steel and concrete tanks, the grape varieties themselves have mutated immensely over the millenia. Even if you made the wine exactly like the Romans did, it wouldn't necessarily taste the same. And just like today, a lot of writing on wine wasn't very detailed about the taste! Most people were fine with just judging it as "good" or "bad" or making generic descriptions of sweetness or bitterness instead of waxing poetic about the flavor of strawberries, fig jam, soil, walnuts, etc.

What we do know is that the Romans had a lot of different varieties of wine, probably at least as many as there are in former Roman territory now. They differentiated by place rather than grapes, so wine would be labeled as coming from Pompeii or Rhodus and have a particular reputation. Wine was an everyday drink in the Mediterranean rather than a luxury, so it was produced everywhere that grapes could be grown and often consumed locally shortly after production was finished. Red, white, and rose wines were known and produced in much the same way as they are today, but they didn't have the same strict classifications so we can only guess from descriptions of the color and flavor; rose is actually the easiest wine to make as it's simply made by mashing the whole grapes with the skins, without the additional maceration needed to get red wine.

All of these varieties of wine were written about. Gaul produced a sweet, brownish-red wine that was said to give a nasty hangover. Turricuar was described in a way that suggests a dry white wine. The most prized wine was Falernian, an expensive white wine from near modern Naples that could be aged and oxidized until it turned brown. It was a rich, sweet, intensely flavored dessert wine drank by emperors and the wealthy. As you can probably guess, a lot of unscrupulous people made and sold fake Falernian for much cheaper.

The Romans did a lot to adulterate their wine, both good and bad. At a minimum it was watered down; drinking undiluted wine was considered barbaric. Wine was commonly drank throughout the day in a 3:1 ratio of water to wine, which creates a drink that looks very much like wine but tastes like water with a faint wine aftertaste. A whole sextarius (roughly a pint) of this diluted wine would only have the alcohol content of a modern 6 oz. glass of wine, and diluted wine was often sold by the sextarius at taverns and eating counters as a common drink.

For the good, wine was often mixed with honey and spices. Conditum paradoxum was made by steeping honey, pepper, mastic, laurel, saffron, dates, and date seeds in wine to create a sweet and elaborately flavored drink. For the bad, wine was preserved or flavored with ingredients that ranged from the unusual (seawater and medicinal herbs like vervain) to the disgusting and potentially dangerous (marble dust, pig's blood, and lead).

Because of the lack of modern preservation techniques like refrigeration and the warm Mediterranean climate, wine tended to go bad relatively quickly and anything not carefully aged like Falernian would have to be drank quickly to avoid it turning vinegary. Part of the adulteration and dilution was likely because of this exact problem with the wine tasting off when you finally get to it. When wine finally soured into something like vinegar, you could mix it with water to create a drink called posca. This was the extremely cheap beverage of the poor and Roman soldiers; the sour wine given to Jesus on the cross was actually a soldier giving his posca ration to a dying man.