Stout Beer Brands: The Substyles and What to Try

In my own homebrewing, stout is where I always send beginners first, since the style forgives a lot of mistakes. Stout was born in London in the 18th century as a stronger variant of porter, so much stronger that early brewers literally called it “stout porter” before the name shortened. Modern stouts no longer have to out-muscle porter in strength, but the family has split into four substyles with genuinely different flavor profiles, from a session-strength Irish dry stout to a barrel-aged imperial stout pushing past 12% ABV.

Dry Stout (Irish Stout)

Dry stout is the style most people picture when they hear “stout” at all: Guinness Draught is its defining commercial example. Most versions rely primarily on roasted barley rather than chocolate or black malt for their dark color and coffee-like bitterness, and the level of roast character and dryness varies more than you’d expect between brands. Bottled versions of the style are often brewed to a higher original gravity and labeled foreign extra stout if strong enough to qualify.

Oatmeal Stout

Oatmeal stout descends from “nourishing” or “invalid” stouts marketed around 1900, historically brewed with oats for a supposedly healthful quality. Modern versions use a genuinely noticeable quantity of oats, 5% to 20% or more of the grist, which gives a smooth, almost velvety mouthfeel that’s softer and less bitter than a dry stout. Samuel Smith’s Oatmeal Stout, brewed in Tadcaster, England, is one of the style’s longest-standing commercial examples.

Milk Stout (Sweet Stout)

Milk stout takes its name from lactose, milk sugar, which yeast can’t ferment, so it stays in the finished beer as residual sweetness. Developed in England in the early 1900s and historically marketed as a tonic for invalids and nursing mothers, the “milk stout” label is technically no longer permitted on beer labels in England, though the name persists elsewhere. The result is noticeably sweeter and less bitter than a dry stout, with a mild rather than burnt roast character. Left Hand Milk Stout Nitro, brewed in Colorado, is one of the most widely distributed American examples.

Imperial Stout

Imperial stout, also called Russian imperial stout, traces to strong English porters brewed for export in the 1700s, said to have been popular at the court of Catherine the Great. The style nearly died out after the Napoleonic Wars disrupted trade, then was revived first in England as an export throwback and later extended by American craft brewers into the modern 8-12%+ ABV category. Founders KBS (Kentucky Breakfast Stout), bourbon barrel-aged with coffee and chocolate, is one of the most sought-after modern American examples, typically released as a limited annual batch.

Where Stout Actually Comes From

“Stout” originally described any strong beer, not a specific dark color or recipe. There were pale stouts and brown stouts long before the term settled on dark porter-derived beers specifically. Guinness, founded by Arthur Guinness in 1759 at the leased St. James’s Gate brewery in Dublin, didn’t start out brewing stout at all; the company built its early business on ale and porter, only becoming the dominant global stout producer over the following century as Dublin and London developed rival porter-and-stout brewing traditions that were, in the beer’s early decades, nearly identical brews.

Imperial stout has a stranger origin story. London porter brewers began exporting an “extra stout” version of porter to the Baltic states and Russia from the late 1700s onward, and it picked up the “imperial” name after becoming a favorite of the Russian imperial court under Catherine the Great; a 1796 diary entry describes porter “specially brewed for the Empress of Russia.” A surviving 1856 recipe for Barclay Perkins’ Russian Imperial Stout, the style’s defining early example, shows an original gravity corresponding to well over 10% ABV with more than 10 pounds of hops per barrel, brutally strong and bitter by the standards of the time.

Picking the Right Stout for What You Actually Want

If you want something closer to the original Irish style, dry stout (Guinness Draught above) is the reference point: light body, high carbonation from nitro, minimal sweetness. If you want dessert in a glass, go oatmeal or milk stout, both built around residual sweetness that dry stout deliberately avoids. Imperial stout is the one to reach for if you want something closer to a nightcap than a session beer, given the ABV range most modern examples sit in (8-12%, following that same Russian imperial tradition). None of these substyles are interchangeable in practice, so matching the substyle to the occasion matters more with stout than with most other beer families.

FAQs

What’s the difference between a stout and a porter?
Historically stout was the stronger version of porter (originally called “stout porter”), but modern stouts and porters are brewed to similar strengths, so the line today is mostly about grain bill: stouts more often use roasted barley, porters lean more on malted dark grains.

Is milk stout actually made with milk?
No. It’s brewed with lactose, milk sugar, which adds sweetness because yeast can’t ferment it, not with dairy milk itself.

Why is imperial stout so much stronger than other stouts?
It traces to strong English export porters from the 1700s brewed to survive long sea voyages, a tradition modern American craft brewers picked up and extended further, often to 10%+ ABV with barrel aging.