As a self-identified lover of dark beers and beer geek, I’m often asked the same (excellent) question: What is the difference between Porters and Stouts?
The first layer is pretty straightforward: Potency.
Porters came first and, really, begat all other dark beers. By the 1720s, the beer was named for the working class men who most frequently drank them – ships porters who carried cargo onto and off of vessels in London – and the style continued to rise in popularity during the industrial revolution. An aside: the original British Porters are nothing like the porters we typically drink today (although there are a few examples out there) – they tend to be a bit tart, perhaps even a hint sour, because of the wild yeast that often “infected” the batches.
At this time, a particularly potent porter was called a Stout Porter. Less water = more potency. Over time the “porter” portion was dropped and the “stout” was born.
This first layer of definition between the styles dissolved quite some time ago. Okay, a long long time ago.
With the advent of numerous permutations of both the Porter (British, American, Baltic) and the Stout (dry, milk, oatmeal, export, american and imperial) there are many many additional layers to dissect! A milk stout and a dry stout side-by-side have almost no similarities, at first comparison, besides the color – but they’re both stouts??? Compare and American stout to an American porter and hunt for differences. Depending on the ones you choose and how sensitive your palate is, you may not find many…
There is a LOT of overlap between the two. But if I had to put a generalized label on it, I might say that, when tasting, a stout tends to be roastier whereas porters are more caramel-y… Offically (as in beer judge certification rules official), porters are drier but that doesn’t hold up in light of the many faces of stouts… so maybe scratch that…?
Getting frustrated yet?
In short, the answer is that there is no answer. The line is blurred. I suggest going to your favorite beer bar, ordering a taste of each and asking the bartender. They won’t have an answer either, but it will make for some excellent conversation!