Stout beer originated in London, England, emerging in the early 18th century as a stronger version of porter, the dark beer that dominated the city’s brewing scene starting in the 1720s. The word “stout” originally had nothing to do with color or roasted flavor. It simply meant “strong,” and a “stout porter” was a porter with higher alcohol content, typically above 7 percent. Over the next century and a half, stout gradually became its own category, distinct from porter in both name and character.
Porter: The Beer That Started It All
To understand stout, you have to start with porter. In 1722, a London brewer named Ralph Harwood at the Bell Tavern in Shoreditch created a blend of various beers in a single cask, sold under the name “Entire Butt.” This was designed to replicate a popular pub practice of mixing different styles at the tap, and it caught on fast. Porter became the defining beer of 18th-century London, cheap and satisfying for the city’s working class, particularly the street and river porters who gave the style its name.
Within a few decades, London’s largest breweries were built on porter production. Thrale’s Brewery on Bankside became one of the most prominent, and the style spread across Britain and eventually to Ireland. When brewers wanted to distinguish a stronger batch of porter, they called it “stout porter.” At this stage, the two beers were essentially the same product at different strengths. By the 1860s, though, stout and porter had become recognized as two separate products. Stouts were brewed with a higher original gravity (meaning more fermentable sugar at the start) and were more heavily hopped.
The Invention That Changed Dark Beer
A pivotal moment came in 1817, when an English inventor named Daniel Wheeler patented a drum roaster that could roast malt at high temperatures without charring it. Using a modified coffee roaster, Wheeler produced what became known as “black malt” or “patent malt,” which yielded a deep brown color that dissolved easily in water. Only a small amount was needed to darken an entire batch of beer. Before this invention, achieving a dark color required large quantities of brown malt or long aging. Wheeler’s black malt gave brewers precise control over color and introduced the intensely roasted, coffee-like flavors that define modern stouts.
How Stout Reached Russia
London brewers didn’t just sell stout locally. By the 1760s and 1770s, Thrale’s Brewery was exporting strong porter to Russia and the Baltic region. These beers needed extra alcohol and hops to survive weeks of travel by sea, and the cold climates at their destination suited a rich, heavy beer. Catherine the Great, who ruled Russia from 1762 to 1796, is the historical figure most associated with early Russian Imperial Stout. In 1796, Thrale’s supplied a specially brewed porter to her court, designed to be robust enough for the journey and reportedly capable of keeping for seven years.
The term “Imperial” to describe these stronger versions started appearing in English brewing records by the 1820s. These beers were powerful: around 10 percent alcohol, brewed from a blend of pale, amber, and black malts, and loaded with roughly four times the hops of a conventional beer. Russian Imperial Stout remains one of the most celebrated substyles today, though it’s thoroughly English in origin.
Ireland’s Role in Shaping Stout
Ireland, and specifically Dublin, became synonymous with stout largely because of one brewery. Arthur Guinness began brewing ale at St. James’s Gate in the 1750s, then started producing porter in the 1770s after seeing the success of the English style. His porter sold so well that by 1799 he brewed his last ale and committed entirely to dark beer. Over the following generations, the Guinness brewery refined its product into what the world now recognizes as dry Irish stout.
What makes Irish dry stout distinct from its English ancestor comes down to one ingredient swap. As Guinness brewmaster Stephen Kilcullen has explained, Irish stouts use unmalted dark-roasted barley for color and flavor instead of roasted malted barley. Because unmalted barley contributes little sugar or body to the finished beer, the result is drier, less sweet, and carries a sharper, almost astringent roasted character. This is why Guinness tastes so different from a thick, sweet English stout, even though both trace their lineage to the same London porter tradition.
New Ingredients, New Styles
British tax law played a quiet but significant role in stout’s diversification. For most of brewing history, the government taxed specific ingredients, which limited what brewers could use. In 1880, Gladstone’s Free Mash Tun Act changed the system to tax the strength of the finished beer rather than the raw materials. This freed brewers to experiment with ingredients that had previously been impractical or illegal to include.
Milk stout was one result. The idea of adding lactose (a sugar derived from dairy) to beer was first proposed in 1875 by John Henry Johnson, who patented the concept as a “nutritive beer” before anyone had actually brewed one. It took until 1907 for the Mackeson brewery in Hythe, Kent, to produce a lactose stout, which hit the market in 1910 with the bold claim that “each pint contains the energizing carbohydrates of ten ounces of dairy milk.” The nutritional promises were exaggerated, but lactose did give the beer a smooth, sweet body that set it apart from dry stouts. Milk stout became a popular style marketed to nursing mothers and the elderly as a health tonic well into the 20th century.
Oatmeal stout followed a similar arc. Adding oats to the grain bill produced a silkier texture and slightly nutty flavor. Sales flourished in the late 19th and early 20th century, but by the 1950s most breweries had stopped making oatmeal stout. By the early 1970s, no commercial examples existed anywhere. The style was rescued from extinction when Samuel Smith’s brewery in Yorkshire revived it in the late 1970s. That single decision sparked a wave of oatmeal stouts from craft breweries on both sides of the Atlantic.
From London to Everywhere
Stout’s journey follows a clear path: it was born in London as a descriptor for strong porter in the early 1700s, shaped by Daniel Wheeler’s roasting technology in 1817, exported to the Russian court as Imperial Stout, and transformed in Ireland into the dry, roasted style most people picture today. Along the way, British law changes in 1880 opened the door for milk stouts and oatmeal stouts, adding sweetness and texture to a family of beers that had started as a simple, strong dark ale.
The craft beer movement of the late 20th and early 21st centuries pushed stout further, with pastry stouts, barrel-aged versions, and coffee stouts becoming staples at small breweries worldwide. But every one of them traces back to those 18th-century London porters and the straightforward idea that a stronger batch deserved a bigger name.