Here is an interesting article my wife emailed to me today:
In today's excerpt, in the Middle Ages, both water and wine are hazardous and often highly unpleasant to drink. Using spices in wine helped mitigate one part of the problem:
"[Wine and ale were] certainly better than the available water. ... Particularly in Europe's densely crowded towns, with their poor drainage and rudimentary public hygiene, untreated water was a daily reality and an extremely effective vector of infection. ... It was most likely the physical consequences of drinking untreated water that explain the severity of a diet of bread and water, often handed out to errant monks as punishment or adopted willingly as a form of penitence ...
"Spices were, if anything, still more in demand in medieval wine and ale ... 'in order to keep the taste of the wine preserved.'
"Taken neat, medieval wine could be a harrowing experience ... the wine consumed at the court of King Henry II tasted like paint stripper: it was 'sour or musty; muddy greasy, rancid, reeking of pitch and quite flat. I have witnessed occasions when such dregs were served to noblemen, they had to sift it through clenched teeth and with their eyes shut, with trembling and grimacing, rather than just drink it.'. ...
"[The problem stemmed] from the barrels in which wine was shipped and stored. Even if the wine survived shipping and storage in a reasonable condition in the barrel--a big 'if,' as barrels were often poorly sealed--the contents began to oxidize as soon as the barrel was tapped, rapidly acquiring a powerfully unpleasant taste, variously described as bitter, musty, smoky, ropy, or cloudy. To get the wine at its best, the contents of the barrel had to be drunk within the space of a few days--fine for feasts and binges but less than ideal for all but the largest or most alcoholic of households. ...
"With the advent of the technology of the bottle and cork in the sixteenth century, the need for spices in wine was abruptly less pressing. Winemaking techniques and the quality of the end result improved."
Jack Turner, Spice, Vintage, 2004, pp. 113- 117.