Upvote:-3
When people invent something - like boats - they experiment with them - like making them larger and larger - into eventually ships. Hence, likewise with alcoholic drinks like wine. It's easy to imagine that Romans could well have distilled ever stronger wines.
In fact, a friend of mine reported an immensely strong drink from South America. I forget how strong. But if memory serves around 80%. This is the higher limit of absinthe, being between 45-75%. I doubt that was an invention of the indigenous Indians but probably of the Latinos that settled in Chile.
Upvote:6
Strength of drink was always a matter of choice.
All distilled beverages are produced by taking distilled alcohol and adding more things - usually water, sugar, and/or herbs. The technology to produce more or less pure alcohol to which these things would be added significantly predates absinthe, and choosing to bottle it at a high proof is a matter of taste. The relevant Wikipedia page discusses how distillation techniques evolved over time.
Neither did the Romans have such weak wine as you claim - while it is difficult to determine exactly how strong it was, 4% is probably the number after dilution rather than before, given that Romans had the technology for mead clocking in at 12% ABV. 3-5% is in the ballpark for strength of early beers, as well, which were not drunk diluted.
Note that distilled alcohol was initially the domain of alchemists and medicines, and would only be consumed as a beverage later on. High-ABV alcohols are a relatively modern taste. Whisky or brandy as a beverage only became common around the late 15th or early 16th centuries, although unaged brandy would have been added to wine to produce fortified wine (which would then spoil more slowly) even before it was consumed on its own. Explaining why people started drinking high ABV beverages would be a whole separate answer - if I had to speculate I would say that purification technology made it more palatable as you could remove the impurities entirely rather than merely dilute them.