Porter and Stout have both been around for centuries. But their co-existence has shifted, weaving in and out of each other’s histories, sometimes overlapping, other times with one or the other more popular, and they’ve certainly not always tasted the way they taste today.
It’s often said that Porter came first, but that’s not true. Not technically, anyway. And Porter as we know it today has a far more recent identity compared to the beers which were made famous in London a few hundred years ago. But let’s go back to the early 1700s and try to track it from the beginning.
Porter is a beer wrapped in myth and anecdote. It begins with brown beer in the early 18th century London. Brown was the standard beer of the day and you could go into a pub and order ‘Mild’ or ‘Stale’ versions of that same brown beer; the stale was an older version of the younger, sweeter brown. Brewers delivered the beers to pubs soon after primary fermentation was done and the pub matured the beers themselves.
Other beers were also available, including Amber, a variety of Ales, and Stout. The ales were less-hopped than the beers (the old differentiation of hop-less ales and hopped beer was beginning to change by this point), while Stout could’ve been any type of beer or ale and its name referred to it being a stronger ‘stouter’ version. It was supposedly common for a drinker to have a preferred mix of different beers poured into one tankard.
By the mid-1700s, as the industrial revolution reached brewing, those brown beers matured into Porter, with the shift effectively happened when breweries aged the beers themselves instead of letting the pub do it. Porter became the first industrially-produced beer, and something brewed in huge volume inside huge wooden tuns. By huge, they were enormous: some held 5,000,000 pints of Porter. And brewers had many of these massive wooden tuns.
Those epic vessels were filled with dark beer and it was left for around six months as it slowly ‘staled’. Porter was initially robustly strong, around 7% ABV in the mid-1700s, heavily hopped, vinous and funky with Brettanomyces yeast (the name means ‘British fungus’ and it was first isolated and identified in Porter). The time in tuns would’ve mellowed the beer, using the hops’ antibacterial qualities as the gatekeeper against any uninvited microorganisms, and allowing the Brettanomyces yeast to convert more of the malt’s sweetness, leaving something tarter and drier than the sweeter, milder version.
By the 1800s, ABV had dropped to around 5% ABV (because of higher taxes), but it was still long-matured in Porter tuns, and it was London’s beer: in 1823, Porter production topped 1.8 million barrels in London. But then the decline began as Milds grew in popularity with drinkers favouring the sweeter, more bitter, less tart younger beers, and as other beer styles, like Pale Ale, started to become more prominent. A century after its peak, Porter had effectively disappeared and Stout had become the popular dark beer on the bar.
Stout came before Porter. Sort of, anyway: the name ‘Stout’ was used before the name ‘Porter,’ although Stout wasn’t a style and instead it was used like we might use ‘Double’ or ‘Imperial’ today – a prefix to explain that it was a stronger version of a regular beer.
Perhaps confusingly, ‘Imperial’ was also used back then and it was a designation of the strongest beer a brewery made, where Imperial Porter was actually used before Imperial Stout and you could’ve seen an Imperial Brown Stout Porter. Anyway…
Over time, and through a hard-to-trace dilution, Stout came to refer to a strong dark beer and then just a family of dark beers, with breweries producing a range of Stouts from ‘single’ weaker ones through to Imperial-strength.
All of this would change through the World Wars when beer production was impacted by roasted barley rationing and a general change in taste, in part brought about through the commonly-held belief that ‘Stout was good for you.’
As the wartime recovery took place, Stout became the fashionable and ‘healthful’ beer while Porter, much weakened by rationing, became an old-fashion relic that was left behind – indeed, it suffered a temporary extinction, disappearing for decades, until new microbrewers of the 1980s brought Porter back.
Now Porter is back and it sits with Stout on bars and in fridges once again, where the modern brews taste nothing like those from the 18th century.
It’s not a black-and-white answer and there’s great overlap, with Porter and Stout being dark beers with relatively broad flavour spectrums, all with a depth of dark grain, and all without strictly-defined qualities.
If you want to find a difference, then Stout will likely have more coffee-like roasted barley bitterness which brings with it a drier finish, whereas Porter might have more chocolatey, sweeter malts and a little extra malt body. But on a Venn diagram of the two beers, the middle overlap will be the largest section, collecting together these two great beer styles with general similarities.
Anchor Porter is a textbook example of one of the original brews to bring this great style back to attention. It has a full malt body, a rounded roastiness that stops before it gets bitter, leaving you with more of the chocolate and caramel flavours, plus a berry-like finish.
Jopen Extra Stout doses harder on the roasted barley for a coffee-like edge of bitterness. It’s a Dutch Stout and that gives it a lighter body – think Schwarzbier – than other examples of the beer, leaving a cleaner, drier finish.
Galway Buried at Sea is a great example of the sweeter evolutions of Stout. It’s a Milk Stout, brewed with milk sugars and chocolate for added richness, dusting the familiar dry roasted bitterness with some sweet cocoa. You’ll also see Oatmeal Stouts, like Samuel Smith’s excellent example, which are also sweeter, richer and fuller-bodied in comparison to Dry Stouts.
Porter and Stout are styles which grew up together, not always going in the same direction, but with significant interweaving through three centuries of ever-evolving brewing. They’ve changed greatly from the original brews but have emerged into the era of craft beer as two of the world’s great beer styles.