Porter and Cask Bitter Ale are widely considered as two of the most classic British beers. Porter, with its origins dating back to the 18th century, was a popular beer among porters. During the height of the British Empire, the maritime trade thrived, leading to a booming porter industry for the hardworking laborers who naturally sought alcoholic drinks to relax.
In the 16th and early 18th centuries, a popular beer cocktail called “Three Threads” emerged in London. It combined beers of different strengths, colors, and flavors (typically three), enhancing the beer’s taste and overcoming the limitations of fermentation technology at the time. Additionally, it helped mitigate the unpleasant taste caused by the hardness of water. This beer gained immense popularity, especially due to the distinct flavor of heavy and dark beer, giving rise to the caramel aroma and sweetness found in today’s Porter beer.
By 1730, a local brewery called Harwood developed a recipe resembling the “Three Threads” cocktail. This new beer, named “Entire Butt,” closely resembled the taste of the original cocktail, but was made directly from a fermented beer formula. Entire Butt quickly gained popularity in London and eventually replaced the original beer cocktail, especially among the Porter community, which later led to the name “Porter.”
Early British Porter beers had higher alcohol content, often reaching around 7 degrees. Some stronger variations even served as precursors to Stout Porter and Imperial Stout Porter. However, its development was hampered by various wars. The reasoning behind this was simple: brewing materials are considered food, and during times of war, taxes on brewing materials would inevitably increase. Following the Napoleonic Wars (1803-1815), the alcohol content of Porter was artificially reduced to 5 degrees or even lower due to taxation.
The earlier Porter recipes primarily consisted of pure brown malt, a malt that had been roasted to give it a distinctive aroma and brown color. However, this changed with the advent of the industrial and technological revolution. The thermometer was invented in the 1760s, followed by the hydrometer in the 1770s. Brewers realized that relying solely on pure brown malt hindered sugar efficiency, as one-third of the malt did not produce sugar at high temperatures. As a result, many brewers began using a higher proportion of light-colored malt (which had higher sugar efficiency) and a smaller amount of roasted black barley (which provided color and depth but had very little sugar content).
However, the use of roasted black barley violated the British beer purity law of the time, as it involved processing a supposedly undesirable food product. This changed when Mr. Daniel Wheeler patented a barley treatment method in 1817. The patented barley, treated at a temperature of 200 degrees, achieved a European Brewery Convention (EBC) color index of over 1300, resulting in an almost pure black color without any enzymatic components. After the patent was granted, this barley became widely used in Porter production and came to be known as Black Malt.
A typical Porter malt recipe during that time consisted of 95% light malt and 5% patented malt, greatly improving the brewing efficiency of Porter beer. Prior to Porter, most British beers were unfiltered and matured in wooden barrels at pubs. However, Porter revolutionized this process by being produced and matured in large wooden barrels, allowing for instant beer consumption.
Mexand Company Brewery, a well-known brewery in London, adopted a method of brewing in giant vats. How big were these vats? 610,000 liters! That’s equivalent to 600 tons! Even by today’s standards, these are still massive containers. On October 17, 1814, disaster struck when one of these large vats exclaiming “Brother, I can’t hold it any longer!” collapsed and caused a massive beer flood. The powerful torrent of “beer” smashed several adjacent vats, resulting in the chain reaction that caused unimaginable destruction. Approximately 1.47 million liters of beer surged out, forming a strong and destructive flood.
Due to the nearby slum housing with low-quality structures, the torrent quickly demolished houses on two adjacent streets, even flooding basements. Thanks to the timely efforts of local civilians, the damage was somewhat mitigated, but the flood resulted in the unfortunate death of eight individuals. Many of those involved in the relief efforts later shared their experiences with the local newspaper, with some stating, “I’ve never encountered such an astonishing flood, I feel like I’m drunk.” In fact, the surrounding neighborhood reeked of alcohol. These people were indeed intoxicated. This stands as one of the greatest beer disasters in human history, caused by Porter.
Unfortunately, as the United Kingdom faced the horrors of World War I and World War II, the country’s reliance on external food supplies created numerous difficulties, repeatedly leading to restrictions on beer production. By the 1950s, Porter beer, with its long-standing heritage, completely vanished from England.
It wasn’t until 1978 that a traditional Porter beer was revived by a small and fine brewery called Penrhos. Thanks to the efforts of the renowned British brewery Fuller’s, Porter beer began its slow recovery and flourished once again.
Today, in most cases, Porter refers to this traditional British beer. While variations have emerged, incorporating flavors such as honey, vanilla, coffee, chocolate, and brown sugar, as well as various barrel-aged versions, they still pale in comparison to the glory of Porter beer. Its brilliance was unintentionally transferred over to Stout beer.