This isn’t entirely true in my understanding, Steven.
My own learning as a pure layman is that most people did drink mostly water. When clean water was available (or even not-that-clean-but-passable-water) that was what they drank.
However.
Much historical fiction, and indeed much historical writing, takes place in contexts where clean water wasn’t readily available, or with social classes that had ready access to the finer things in life. Armies on the march tended to befoul the fuck out of any water source they came across. Cities were just cesspits of disease, poisoning the rivers and water tables they were built on for leagues around. And in those contexts people are going to be drinking beverages with alcohol in them because, indeed, it is either much safer, or they’re of a social class where they can afford it. Because we’re not reading about the 90% of the country that lives a rural lifestyle and mostly drinks mostly water they pull from wells, streams, and rivers, with the occasional alcoholic drink mixed in.
I could be wrong here, tho.
Consider this a placeholder until I find the post where I did the research on the royal decree that limited inns to one per village, because people liked to drink just that damn much.
Ok, I knew I had read this somewhere. So to give one example of how much medieval people loved their booze: in 965, King Edgar the Peaceable of England issued a royal decree that there could only be one alehouse per village, “and had pegs put in the drinking cups to mark how much any person might consume at a single draught.” So in a country of between 1-2 million people living in 13,000 towns and villages (which suggests around 153 people per village), there were at least two alehouses per village (or one alehouse per 76 people).
See, the thing about the “rural lifestyle” is that it usually gives you the raw materials to brew your own ale and beer and then sell the surplus to your neighbors. To quote from Margaret Schaus’ Women and Gender in Medieval Europe:
People did drink water, but the cleanliness of the water was quite iffy, so people tended to drink alcohol as it was safer.
Ale was the common drink of people in northern Eirope; it also played a prominent part in medieval culture. Safer to drink than water, the grain-based beverage provided an important part of people’s daily nutritional requirement…for most of the Middle Ages, brewing was dominated by women. Because of its importance, ale’s production and sale became subject ot extensive regulation; as a result, alewives (women who brewed and/or sold ale) are much more visible in the records than most other medieval female workers.
In England, the late thirteenth century assize of ale, enforced by local officials, regulated the price and quality of ale…brewing was a domestic skill expected of medieval women, Because ale spoiled quickly, many rural households alternated between brewing their own ale and selling any surplus, and purchasing it from neighbors. Brewing for sale was a part time occupation, undertaken to supplement household income…
…demand for ale increased with rising living standards after the Black Death, providing more opportunities for women to earn a full- or part-time living from brewing…in England there was an increase in the number of alehouses…
And then hopped beer spread out of Germany into Northern Europe starting in the 14th century, and as hopped beer “lasted longer and could be made in larger quantities,” you get even more booze, now produced more by men who could afford to make the “greater capital outlay” required to brew hopped beer.