Mad about Science: Medieval brewing

By Brenden Bobby
Reader Columnist

Anywhere you travel — from New York, U.S. to York, U.K. — you can expect a uniform taste from two of the same brands of alcoholic brew. Modern brewing is a carefully controlled process that is carefully monitored to maintain uniformity. Different batches of beer with different ingredients may taste different, but you can always expect a can of Pabst to taste the same.

This was not common throughout most of human history. In many cases, two batches from the same brewer may taste completely different from one another. What changed to bring uniformity and consistency to brewing?

Stainless steel, mostly.

At its most basic level, stainless steel is steel that has been mixed with chromium; when the chromium oxidizes, it creates a layer that locks in everything beneath it while remaining relatively smooth on the surface, unlike iron oxide rust that chips and flakes and leaves plenty of pockets for bacteria and other gunk to collect. This self-healing property of stainless steel makes it incredibly easy to clean and sanitize, which is the reason it’s used in so many kitchens and breweries today. Spray it down with pressurized water, some soap or even a little scrub, and you’re essentially good to go.

Medieval brewers had no access to stainless steel. The first attempts to create stainless steel weren’t even attempted until the 1790s, well after the conclusion of the medieval period. Often during the Middle Ages, brews were fermented inside wooden casks, which offered a plethora of hiding places for yeast and bacteria to live.

Despite complete ignorance of the idea of the microbiome, medieval brewers were generally pretty good at what they did. Perhaps through centuries of trial and error, brewers figured out how to manipulate yeast and ingredients to create something palatable without worrying about invisible organisms. These organisms existing and evolving independently from one another altered the taste of brew from one cask to the next.

Brewing in the medieval period was reminiscent of brewing today in the sense that it was extremely accessible. Aristocratic families would often act as large brewers and, to some extent, distributors much like mega-brewers today such as Anheuser-Busch. These families had the resources to create large amounts of brew to a specific standard and then export it to neighboring lands or even ship it abroad.

Monasteries, particularly in medieval England, acted in a similar fashion to specialized artisanal breweries today. They were well funded by the Catholic Church, were relatively insulated from threats — Viking invasions notwithstanding — and allowed to operate with a certain degree of political immunity. 

They also specialized in brewing wine for communion, and medieval monks and nuns viewed the process of brewing and imbibing as a means to bring themselves closer to the divine. Wine was an expensive commodity during this period, and it often wasn’t shared among the common flock, even during mass. This was a specialty that was reserved for the clergy and aristocracy of the time — at least in England.

Home brewing was an even bigger deal in medieval England than it is today. We all know that one guy who won’t shut up about brewing his own pilsners in his garage, but there was nothing unique about that in medieval households. In fact, there was a special punishment for people who botched their brew and shared it with their friends.

The brewer and disseminator of substandard beer would be forced to sit outside for a full day to be shamed by everyone who passed by their home. Even those who had not imbibed the offending tipple were encouraged to participate in the punishment, as a particularly bad brew carried the potential to kill.

Have you ever wondered why pubs have such a homey feel, compared to American bars? This was an extension of medieval homebrewing. Folks who became especially skilled at making their own brews were popular people who attracted friends and neighbors to their home with their intoxicating creations. Often, a drink outside the door would evolve into entering the home for another, chatting about news and events of the day, eating and general merriment. After some time, folks figured out this could be a profitable pastime and began pairing it with events like cockfights, which gave rise to the heraldry that adorns many pubs throughout the U.K.

Pub heraldry was especially important during a time when most common people were semi-literate at best. Publicans used their signs like movie posters, catching the attention of passersby and previewing what the pub had to offer. 

At one time, many of these signs became so heavy and elaborate that they began falling off their buildings and killing the clientele. That led to an effort by authorities to standardize the signs, which is believed to account for the smaller, more compact signs hanging outside modern pubs.

As a final tidbit of medieval brew-related information, “beer” as we would know it was extremely rare until much later in English history. The defining characteristic of beer is the inclusion of hops, which didn’t thrive in the cold, damp English countryside. The crop did grow more readily in places like Germany, Spain and Italy, though wine grapes were found to be far more profitable in those regions than bitter hops. Ale was the preferred brew of medieval England.

A common misconception of the medieval period was that all water was too tainted to drink, and thus people drank ale and beer instead. This may have been true in densely populated London, but most folks in rural communities just enjoyed drinking alcohol. Honestly, if you worked manual labor for every sunlit hour of the day, could you blame them?

Stay curious, 7B.