The short story of porters

The exact origin of porter – similarly to the case of the IPA – is clouded due to several reasons. It is certain though that several factors combined together led to the development and immense success of this beer style. During the onset of the 1700s, in the wake of the industrial revolution there were 194 breweries located in London, with an average production that would be on par with a modern microbrewery. Whilst these common breweries (a brewery supplying a handful of inns and taverns, as opposed to publican or homebrewing responsible for stocking a single venue) could fulfil the volume demand for beer for the city’s dwellers – at least most of it – the developments in trade and transport of goods led to an influx of hoppy and pale ales from other parts of the country, like Burton. London is best known for its brown beers, especially because the local water without modern treatment is ill suited to brewing pale beers, however creative brewers were able to turn this aspect into an advantage. Porter was most certainly hopped more liberally than previous brown beers to compete with the pale ales of the time, however brewers were able to use brown malt as a sugar source, which at that time was more plentiful and readily available, making it a cheap option. Most importantly tough, businessmen realized that implementing the newest available technologies makes it possible to produce beer at previously unseen volumes, resulting in decreasing costs.

Let’s not forget, that simple – by today’s standards – instruments such as the thermometer weren’t in industrial use yet. Due to the lack of objective information, we can only speculate about the exact nature of this beer style. We know the following: the base of the beer was the so called “brown malt”. The distinct qualities of this barley malt are also quite shady; however, we can safely bet that due to the traditional manner it was produced in that the malt was relatively inhomogeneous resulting in worse brewhouse efficiency compared to modern malts, and it probably gave the final beer at least a hint of smokiness. Porter was also hoppier than previous dark ales, to combat the spreading popularity of pale ales. Since yeast as a microorganism hadn’t been discovered by this point in history, the only thing we can say for certain that the strains used were of the top fermenting varieties. What else can we be certain of? Well, porters were aged for a considerable time. Longer than normal table beer would have been aged for at the time, that’s for sure! So, we have an aromatic and heavily hopped (for the time) dark brown ale, which people quickly grew to love. What else is needed for success?

Money. Before hydrometers gained a foothold in brewing, English brewers didn’t sparge. Instead, they reused the same malt over and over again, each mash being more diluted than the previous. The separate wort segments were fermented on their own, resulting in the different “strengths” of beer available at the time: strong, common and small. What was the MAIN difference between these you ask? No, not the alcohol content, nor the flavor intensity but the fact, that each of these categories had its own mandated price and tax. Yes, at this time in history the price of beer was determined by the government! But with the introduction of porter came a change in brewing techniques. Instead of fermenting the wort in batches, resulting in separate beers, the entire gyle (the sum of all wort resultant of one batch of malt) was collected and fermented altogether. This way the whole batch could be called “strong”, resulting in higher profits. So not only was porter very popular, but it was more profitable to produce than other, split-gyle beers of the era. To fully capitalize the immense potential of this new product, industrialist had but one thing left to do; brew as much of it as possible!

Out of the 194 common breweries in London at the start of the century, only a fracture were able to invest into bigger factories, thus the market quickly shifted. During the 18th century around half of these breweries closed their gates. While smaller businesses went bankrupt, the ones that had the capital to invest kept growing. By the end of the century only 115 breweries were still open in London, and the majority of beer production was split between a handful of these endeavors. To brew good porter you need a long aging process. At first this was carried out in barrels, however during the birth of porter new techniques were invented, giving way to enormous wooden fermentation vessels, in which the beer would age up to a year. Whilst during the 1720s the largest, copper lined wooden barrels couldn’t hold more than a couple hundred liters of fluid, a mere ten years later fermentation vessels with a capacity in the hundreds of thousand of liters were already in use around London. This is where economy of scale first introduced itself to the brewing world, giving way to modern, industrial scale breweries. It is important to note however, that this was a very capital-intensive industry; contemporary financial newspapers claimed that entering the porter brewing business required the highest amount of capital, second only to the banking sector.  

Porter became London’s decisive beer style, and kept this title until the start of the 19th century. By this time the city’s porter brewers were brewing this style on a different order of magnitude compared to all other beer style in the area. Brewery sponsored venues – so called tied places – started to pop up, to help lock down retail opportunities for breweries. After a while, tied pubs became the norm, and the concept is a mainstay of industrial sized breweries to this day. The cap for porter’s production volume was reached at the middle of the 19th century; still very popular at this time, however it was already evident that the hundred years old reign of the style is beginning its downfall. By the start of the 20th century, the popularity of porter shrank considerably, as the average drinker was looking for more modern, clear and blonde ales. Also, stouts evolved from porters, offering a trendier alternative to those seeking a dark ale. Between the two world wars, breweries that specialized in porter production either started brewing something else, or closed their gates.

Luckily the style didn’t vanish completely! Besides England, porter made its mark in the history of brewing in Ireland, the USA and in the Baltic states. And due to the recent international craft beer revolution, the original industrial beer style is now readily available again, even if it is not quite the same as it was during its birth in London, at the start of the 18th century.