The Exact Difference Between Stout And Porter Beer

Porter beer originated in 18^th century London, where English dockworkers often spent long, back-breaking shifts loading and unloading cargo from ships for minimal pay. To fortify themselves with the calories they needed to get through their day, they drank beer, lots of it. Eventually, one popular style of beer took on the name that dockworkers were known by: porters. Back in the 1700s, stout beer was simply a stronger version of porter, and it was originally called a "stout" porter.  

At the most basic level, the difference between porter and stout is infinitely simple. Porter is made from malted barley; stout uses roasted but unmalted barley. Malted barley is so named because it undergoes a specific process of steeping (soaking the barley in water), germinating (converting the barley's starch to sugars), and kilning (heating the grain). This series of steps defines the taste, smell, and color of the beer. Unmalted barley is essentially the "raw" grain, which is then roasted. Of course, in today's market, the definition of these styles is far more fluid, but porters and stouts still have distinguishing characteristics that will help you recognize your tipple.

Malted barley is what gives porter its distinct taste, color, and scent. Flavors lean toward nutty, caramel, or coffee-like; colors range from reddish brown to deep brown to almost black, but not as black as stout often is. These beers are often considered easy drinkers thanks to a lower alcohol content than most stouts. The ABV, or alcohol by volume, range of porter is generally around 5% and not higher than 10%. In contrast, stouts can clock in at a whopping 16%, although dry Irish stouts like Guinness are an exception, running around 4%. 

Despite going down smoothly, porters still maintain complexity thanks to the malted grain. Brown English-style porter is less bitter than the others and has the lowest ABV. Next up is the biscuity-tasting Robust American porter, which is a step up from the English style and also a bit more burly. The smoky style adds wood-smoked malt. Both American Imperial porter and Imperial porter are similar, emphasizing coffee and chocolate. And, lastly, Baltic porter, which is considered modern beer's most prominent disruptor, has more alcohol but similar flavors to a brown porter. 

There's an old joke about someone ordering a Guinness stout and then watching it patiently as the prodigious foam that fills up most of the glass slowly settles into a thin cap on top of the almost black beer beneath. Among its characteristics, unmalted barley leads to more foam, or head, on the beer. All stouts are not the same, though; there are subcategories, each offering their own style within the style.

Guinness, which is made by one of the world's oldest continuously operating breweries, is a dry Irish stout, known for its roasted character. The Imperial style has a higher alcohol content and often rich flavors like coffee and even coconut, while pastry stout is almost dessert-like. Coffee, milk, and oatmeal stouts have the characteristics of their namesakes. In turn, coffee is somewhat bitter, oatmeal is cereal-like, and milk tastes almost like coffee with creamer added. And, finally, barrel-aged versions reflect the toastiness of the barrel in which they are stored. These days, as the category grows — many stouts are now produced in the U.S. — the line between style definitions is becoming more fluid. Flavors can run the gamut from bitter to sweet, chocolatey to fruity, and dry to silky. These are brawny, strong brews, not for the faint of heart.