Porter: Three Threads into One

Any beer aficionado would identify the most significant events in brewing in the past three hundred years as the development of IPA by the British, and the introduction of Pilsner in Bohemia. The invention of Porter in the early 18th century was as noteworthy. It signaled a shift in brewing practice, drove the industrial revolution relative to brewing, and sired one of the most-beloved modern beers, stout. Porters birth can be pinpointed precisely, for it was concocted for a specific reason. Porter rose to dominance, was supplanted by its opposite, then its offspring, and eventually disappeared altogether. Given up for dead just three decades ago, it has been resurrected by the current proclivity for historical beers.

Birth of a Style

Most beer styles have a seminal quality to them, having arisen through local agrarian custom, raw materials, and environmental conditions, sometimes fine-tuned by technology. Porter was created specifically to lessen the load on London publicans who served legions of thirsty laborers. They served a blend of beers of various strengths and maturity, usually three, known as “three threads,” but sometimes even more. A mash was saturated and drained three separate times to produce three different worts, with the resultant beers known as strong, middling or common, and small beers. The strong beer was for keeping, and used after a period of maturation during which it developed lactic and musty cask character from resident lactobacillus and Brettanomyces organisms. Small beers were fermented and consumed quickly. Middling beer was somewhere in between. The variety didn’t stop there however. Pale malt, produced around London, and the beers made from it were referred to as “twopenny.” Pale malt, and hence twopenny, were expensive but it nevertheless was a common “thread.” The majority of the beer was some shade of brown, produced by the cheaper amber and brown malt.

It was the brainstorm of Ralph Harwood in 1722 of the Bell Brewhouse in Shoreditch,, and perhaps a few other less famous brewers, that altered London pub culture. Rather than putting the publicans through the rigors of mixing stale, brown, and pale beer, he brewed a beer from pale and brown malt, combining worts previously fermented separately. A measure of stale beer in the cask provided the expected lactic/Brett tartness. The result was a reasonable approximation of the three threads and probably resembled the middling beers mentioned above. Harwood named it “EntireButt.” The sobriquet of porter was adopted because of its immense popularity with the porters who comprised a good portion of the workforce. Not mahogany-black beer as modern drinkers are familiar with, porter was instead brown, a bit rough and smoky, and generously hopped, as hop usage was blossoming as a way to spice and preserve beer.

Industrial Porter

The popularity of porter during the 18th century coincided nicely with the groundswell of the Industrial Revolution. Brewing moguls emerged and built massive breweries to slake the thirst of the burgeoning and, relatively speaking, well-off workforce. Steam-powered engines provided obvious advantages to the mega-breweries. Other, more obscure improvements in brewing technology, also contributed to the bloated nature of the industry. Coopers designed gargantuan aging casks, crucial to the character of porter, capable of holding 20,000 barrels or more of maturing beer. Skeins of these massive vats allowed some brewers to produce over 200,000 barrels of beer per year. Innovative copper cooling systems allowed year-round brewing and storing of beer.

Brewers took advantage of the improving trade routes, and porters popularity, to send their brew throughout England, Scotland, and Ireland. To the disdain of the brewers outside of London, the imported porter was putting many on the verge of bankrupcy. The solution was to make porter themselves. By copying the London brewers, or hiring London-trained brewers, they were able to stay afloat in a very competitive endeavor. Guinness was brewing only porter early in the 19th century, became well-known for its stout, simply a strong version of porter, and eventually exported to England. Within a century, Guinness became the largest brewery in the world.

Paint it Black

Existing for decades as a brown beer, porters complexion was about to change. Three occurrences were responsible for the shift, the first two might having made porter lighter in color before darker. Coke replaced coal as a curing fuel for malt, creating a lighter, amber malt which replaced brown malt as a chief ingredient in porter. Coupling that with the increasingly common pale malt, porter would have taken a pale turn. A second “improvement” among brewing practitioners was the development of the hydrometer, which measured the extract of the mash. Paler malt was slightly more expensive, but it was more efficient and cost-effective in the brewhouse. This was welcomed from the business standpoint, but posed a public relations issue. Porter-drinkers expected their beer to be dark, and like the misconception that persists today, dark beer was associated with strength.

The task at hand was to give the public the beer that they were familiar with. Burnt sugar or wort, molasses, and licorice were added to give some color to the brew. A host of other questionable, toxic, or narcotic substances, were added to the wort to try to capture the public interest. It didn’t work, and porter suffered somewhat in its popularity. To the rescue came Daniel Wheeler in 1817. He fabricated a drum-type malt roaster to produce black malt with precision and reproducibility. Brewers adopted the black malt hastily as a coloring agent and coupled it with the base beer to produce porter. The significance of this device is rather obvious today, considering the continuum of malts available. It sparked an interest in roasty beers and may have been the impetus to produce the familiar stout of today, which supplanted porter as a preferred brew.

From the Ashes….

The irony in the fate of porter in the 19th and 20th centuries is that the things that defined and propelled porter led to its demise. Pale ales saw a meteoric rise in popularity. The pilsners produced in Germany and Bohemia swiftly became the darlings of Europe. Stout was catching the eye of those that wanted a dark beer, but something stronger. Brown ales and milds defined themselves as regional favorites. By the 1940s, porter had essentially vanished in England. Guinness brewed porter until 1972, but ceased its production to concentrate on the vast market for stout. The fate of porter seemed to be a that of a permanently deceased style, perhaps to be appreciated only in an historical context, but the newest wave of brewers were loathe to relegate porter to such a end. Porter symbolizes the resurgence of brewing art and appreciation. The persistence of CAMRA in the UK, and the forward-thinking optimism of microbrewers in North America have leased new life to the style in the late 1970s.

Profiling Porter

Porter today is far different from original, but not unlike those of almost 200 years ago. Black malt is the defining feature. The style guidelines used to critique beer, segregates porter into two styles true to the historical brews, those being either brown or robust porters. A third designation, Baltic Porters, are strong derivatives of porter and stout that were exported to Baltic and Eastern European regions. Most of the Baltics are bottom-fermented, but the Scandinavian versions are truly robust porters. Robust porters are far and away the most common of the three.

Being an ale, porter grists start with a sturdy backbone of pale ale or 2-row malt. English brewers have at their convenience some of the finest pale malt. The full-bodied, chewy quality of this malt is a perfect compliment for the specialty malts that embellish the character of porter. Even the lower-strength versions seem formidable. North American brewers most often go with 2-row that is grown throughout the heart of The United States and Canada. A fine malt in its own right, 2-row may be a bit lighter in character, but it also allows the specialty malts to be the headliner. In fact, it is the multitude of specialty malts that make porters unique relative to both one another and other styles. While a stout relies heavily on roasted barley, porters showcase black patent malt. This is not to say that a porter doesn’t contain some roasted barley though. Chocolate malt is more commonly found in porter versus stout. Body-building crystal or caramel malt adds a bit of sweetness and mouthfeel. Even Munich-style malts are used to give more malty complexity. Some adventurous modern brewers are going the historical route and using a modicum of brown or amber malt. The distinction between brown and robust porters may be blurred at times, but if one must pigeonhole, it could be said that a robust porter is generally deep red-black, slightly higher in strength, and relies more on black malt. A brown porter is indeed deep brown, features a chocolately forefront, and is slightly lower in alcohol. Alchohol by volume for all porters is generally between 4.0 and 5.5%, although some American versions can run up into 6 % or better, with a few “imperial” porters figuring into the mix also.

Porters are also intriguing because of their hop complexity. English brewers tend to stick to Fuggles and East Kent Goldings, but Target, Challenger, Northdown, and Progress are also used. They are hopped for balance. Americans might opt for English hops as a historical nod, but most put a stamp of their own on the beer. High-alpha acid hops like Centennial and Chinook are often evident in the background, and flavor and aroma hops present that familiar panoply of resinous, citrusy, and piney notes. Cascade, Mt. Hood, Crystal, Liberty, and Willamette are as at home in porters as they are in pale ales and are often as hoppy. Some of the subtleties of the hops might get lost in the deep-colored malts, but the marriage add depth and smoothness. In fact, porter can have a more rounded profile than some of the paler ales. It is not unusual to find a porter featuring 5 different malts and 4 or 5 different hops. Comparing American and London porters are like the proverbial apple vs. orange contrast, well-made ones of either are similar but distinctive enough for any beerhead.

Yeast choice adds a another subtle divergence among the porters. English yeasts tend to have a fairly strong influence, and accentuate the malt character of the brew, besides giving the brew that distinctive British character. Those brewed in America lean towards a cleaner yeast for the most part that minimizes the estery or fruity notes. The yeast does its job and then disappears, pushing the malt and hop character to the forefront. Some American yeasts do contribute some character, but compared to its British counterparts, quite subtley.

Porters are very common in both CAMRA-recommended real ale venues, and in brewpubs and microbreweries in the United States. They are, because of modest strength and complexity, a perfect brew to present as a real ale. Many outstanding English porters are exported, with some being brown porters.

On this side of the pond, porters might not be as favored as stouts, but are nevertheless, ubiquitous. Edmund Fitzgerald Porter from Great Lakes Brewing Co. is a cut above most. Most well-known micros produce outstanding porters that are easy to find, and almost any of your regional favorites no doubt offers one. Among the favorite styles of the brewers, it is almost always made with a high degree of proficiency. Porter is experimented with regularly. Smoked versions from Alaskan, Rogue, and Stone showcase the versatility of specialty porter. Mad River Brewings Scotch Porter uses both Scottish peated malt and German rauch malt in a burly, well-balanced porter. Highland Brewing’s Oatmeal Porter exploits the silky quality of oatmeal to enhance the smoothness. All of these fall on the robust side of the ledger.

For sheer versatility, porters are hard to beat, offering sturdiness on the one hand, drinkablility on the other. They can be the epitome of balance, or a dark beer for hopheads. The range of flavors in porter are almost unparalleled, and have as complex a malt and hop bill as any beer. Soothing enough for cold weather, modest enough for warm, porters may still take a back seat to stout, but they occupy the driver’s seat for many.