It’s a rare craft beer drinker who has yet to experience the joy of an inky-dark stout or porter beer. These hearty beverages have been part of the brewing world for centuries, but where did these beer styles come from, and what makes a stout a stout and a porter a porter? Both have a long and closely intertwined history, but we wouldn’t have stout without porter, so let’s start there.
A Porter’s Drink
The true origin of porter is nebulous and shrouded in mystery. Because the beverage developed over time, it’s difficult to accurately credit one person with its creation. A common myth claims that porter came about from a mix of three draft beers known as “three-threads.” The only recorded version of this story is by London travel guide writer John Feltham in 1802, nearly 80 years after the first porter was likely brewed. Feltham claimed that it was common practice at the time for publicans to combine beers from two or more casks into one glass, a popular blend being “three-threads,” or three different beers. To simplify this process, a man named Ralph Harwood is credited by Feltham as developing a brewing technique that preblended the three-threads, making the favorable characteristics of the mix available in one cask, which eventually took on the name “porter.” Although Harwood was indeed a real man (a London brewer who went bankrupt in 1747, during the heyday of wildly popular London porter), there’s little evidence to support the rest of Feltham’s story.
Feltham possibly confused three-threads with the “parti-gyle” brewing practice, an ancient style of brewing in which multiple beers are drawn from the same mash. The first is the highest strength, as it contains the most fermentable sugars. Depending on how many runnings are drawn from that mash, the last running can be as low as 1 to 2 percent alcohol. Porter was often made of a blend of various runnings, possibly leading to Feltham’s confusion.
It’s more plausible that porter came about in the early 1700s as an evolution of brown beer, a common beverage at the time. To prepare malt for brewing, it first has to be kilned. Brown malt was the cheapest malt to kiln at the time, as it could be kilned quickly at high temperatures. The more expensive malts were kilned slowly at lower temperatures, giving them milder flavors. The high heat gave brown malt some unpleasantly harsh flavor characteristics, but also gave it its color and roasty flavor. Eighteenth-century British brewers realized that aging highly hopped brown beer for six months greatly reduced its harsh and hoppy characteristics, making it an affordable drink for the working class. One group of workers who took a ravenous liking to it was porters, whose job it was to carry and distribute cargo throughout the city. They drank so much of the beer that it eventually took on their name.
The porter we know today is a direct result of industrialization and innovation. In the late 18th century, technological advancements, such as hydrometers, thermometers, and steam engines, made it easier to fine-tune and automate beer brewing. When hydrometers, which measure the sugar content of beer wort, made it clear that pale malt was much more efficient than brown malt, brewers began to replace brown malt with pale malt. By the time of the French Revolutionary and Napoleonic wars in the late 18th and early 19th centuries, which caused a drastic increase on malt tax, brown malt accounted for only a very small percentage of the grist, or grain bill. Porter lovers had become accustomed to the dark color of their porter, though, so the less scrupulous of brewers began to use burnt sugar and other nonmalt ingredients to color their beer. When the British government got wind of this in 1816, it outlawed the use of any coloring ingredients in beer other than malt and hops. Following this law, porter brewers struggled to produce a product the public would accept. That is, until 1817, when Daniel Wheeler invented a new style of roasting malt. Wheeler developed a drum-style roaster, similar in design to a coffee bean roaster, which allowed roasters to evenly roast pale malt to a dark color without imparting a strong smoky taste. Due to its intense flavor, only a small amount was needed to turn a mild pale wort into an inky black wort with roasty flavors. Porter was saved, even if it was darker than before. (Porter was originally more brown in color than black, as it was made entirely of brown malt.) If anyone can be given credit for today’s porter, it would be Daniel Wheeler. His patented malt style is still used today by craft and homebrewers, and it’s known as “black patent malt.”
That’s a Stout Porter!
The word “stout” has been used to describe beer for some time, but not the dark beer we know today. For a long time, it was simply an adjective to describe a beer that was stronger than standard strength. “Standard strength” meant various things at various times, but, in general, a pale ale was usually around 4 to 5 percent alcohol by volume (ABV), and anything 6 percent or higher was a “pale stout.” When higher gravity dark ales were brewed, they came to be referred to by their strength: single stout, double stout, triple stout, and imperial stout. Over time, the word “stout” came to be most often associated with porter, and “stout porter” became a well-known term for the stronger versions.
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It took some time for stout to become its own style, and even after the popularity of stout porters, there were still beers brewed with pale malt that were referred to as “stout.” Eventually, though, stout came into its own and was largely recognized as a separate beer style.
Stout was the original overpriced craft beer. It was sometimes aged in barrels, and additional ingredients were added to diversify its flavor — and its price. The diversity of stouts available to us today has its roots in the innovations of the 19th and early 20th centuries. One example is sweet stout, which was brewed in Scotland with a low degree of attenuation and minimal hopping. The low attenuation meant that much of the sweetness of the malt remained, and the low hopping, usually using hops from a previous batch of beer, allowed for minimal bitterness.
The first known, and patented, milk stout, which came about as a variation of sweet stout, was brewed by Mackeson Brewery in Kent, England, in 1907. Like modern milk stout, no actual milk was used. Instead, lactose, a milk sugar, was added during the brewing process. Lactose is unfermentable by brewer’s yeast, allowing for increased body as well as a degree of sweetness that makes for a smoother, less bitter mouthfeel. It was often marketed as a restorative health tonic and recommended for nursing mothers. Though there was some truth to this claim, it wasn’t because of the lactose. Stout beer contains high amounts of barley and is heavily hopped. Both hops and barley are galactagogues, or breast milk stimulants. I brewed stouts for my wife with additional herbal galactagogues when our doctor recommended she have a stout a day while nursing both of our children.
Oatmeal, a common ingredient in stout recipes, is also a galactagogue. Maclay’s Brewery in Scotland developed an oat malt stout by using a grist with about 30 percent malted oats. The brew was so popular that the brewery took out a patent for “Oat Malt Stout,” which was promptly ignored by other U.K. breweries, who began producing beers they termed “oatmeal stouts” using unmalted flaked oats.
Oyster stouts are lesser-known than other stout types, but are still produced today by certain breweries. Originally, “oyster stout” was just a term used by pub-goers who enjoyed slurping an oyster while having a stout. At some point, though, someone decided to add shells to the brew as a fining agent, and eventually the meat itself made its way into the mix. While some oyster stouts may have a hint of salinity, for the most part they taste like regular stouts.
Although Scotland and England produced their share of stouts, Ireland will always be the land of the stout. Guinness is the behemoth that can’t be ignored, but Beamish and Murphy’s sell their share as well. What makes Irish stouts stand out from the rest of the pack is that the malts aren’t roasted as much, giving the beer a smoother, less acrid flavor. They also tend to have unmalted roasted barley as part of the grist, which imparts a drier flavor.
Milk stouts, oatmeal stouts, and Irish stouts are all low-alcohol brews. Rarely more than 4 to 5 percent ABV, they’re meant to be refreshing, easy-drinking session stouts. This is not the case with imperial stouts. Big, robust, and complex, imperial stouts have their origin in stout porters that were shipped to colonies in India and other global locations during the 18th century. India Pale Ale (IPA) was the original champagne of beers, and was mostly drunk by the upper classes. Strong porters, however, took the spotlight in Russia. Brewed at a much higher gravity and with even more hops than standard porter, imperial stout porter was favored in the Russian courts, most notably by Catherine the Great and Grigori Rasputin. (The word “imperial” was meant to designate the final intended recipient of the brew.) It’s not that the relatively short, cold voyage required such a robust brew to arrive intact, it’s just that the Russians enjoyed a boozy, warming drink. And who could blame them? For most of the year, Russia is cold!
Modern imperial stouts can be 9 percent ABV or higher, which is really the only requirement for classifying a stout as “imperial.” Other than that, they can have as much variety as a brewer dares. Because of the nature of the beer, brewers tend to up the ante when brewing imperials. Large amounts of chocolate malt, oats, or even wheat malt are sometimes included. Some have notes of coffee, cherries, raisins, or molasses, and various additional fruits and spices.
All that said, what is the difference between a porter and a stout in modern times? Honestly, it’s whatever you want it to be. The styles have changed so much over time that there’s no cut-and-dried answer. Many porters are of similar alcohol content to certain stouts, such as sessionable Irish stouts, so the original meaning of “stout” isn’t relevant anymore. Stouts can be fuller bodied than porters, but that isn’t always the case. In commercial brewing, it’s the labeling and marketing that really make the difference. If you’re a homebrewer, call it what you want, just as long as your grain bill comprises 80 percent or more pale malts. From there, you can go as dark and funky as you want.
So, now that you know the difference (or lack thereof) between the two beer styles, warm up with a stout this winter and raise a glass to the hardworking porters that made it possible!
The Power in Advertising
When you hear the word “stout,” you probably think of Guinness. The well-known beer has enjoyed celebrity status for decades. What brought this Irish stout to the forefront of beer fame? In short, successful advertising.
In 1929, the company launched the “Guinness is good for you” campaign, practically inventing product branding. Over the years, as alcohol advertising laws became stricter, the campaign slogan changed to “Guinness for strength,” followed by “My goodness, my Guinness,” and then “Lovely day for a Guinness.” The iconic slogans and quirky imagery are what really made Guinness a household name. Between savvy advertising and the opening of multiple breweries around the world, Guinness positioned itself to become a globally recognized brand. It didn’t hurt that they also made a fine-tasting stout.
Jereme Zimmerman is a traditional brewing revivalist, homesteader, and speaker at nationwide natural living events, including the Mother Earth News Fair. He lives in Kentucky with his wife and daughters.