Trying to nail down meaningful definitions of porter and stout is no easy task, and unraveling their thoroughly entwined history is damn near impossible. We’ll take a stab at the definitions and touch on the history at least enough to offer a bit of context. Be warned, however, that the truth is often unsatisfying.
Let’s start with porter. If you look up porter in the dictionary, you’ll see something like this:
porter \ˈpȯr-tər\ n. 1: I have no earthly idea what the hell a porter is.
That is clearly not really the definition, but the real definition isn’t a lot more helpful. You probably already had at least a vague idea that a porter is kind of a heavy dark brown ale, so a dictionary definition is not going to help. Nor does it help to know that porter was (possibly) so named because its popularity among London transport workers.
Which leads us to the first somewhat unsatisfying truth: porter never referred to any single beer concoction. Two brewers in the same city, let alone the same street, may very well have brewed decidedly different ales that were sold as porters. When you consider that characteristics common to some porters changed with the advent of new technology and the addition of new ingredients, we have less of an answer than we started with.
Elusive definition aside, a little research at least reveals some common characteristics of porters for our current practical purposes. A good start is The Oxford Companion to Beer, which offers this:
. . . the best renditions of porter are well balanced and aromatic, with predominant notes of rich chocolate as well as hints of coffee, caramel, nuts, and sometimes a faint smokiness, combined with an oftern dry, even slightly acidic, finish.
That should give you an idea of roughly what to expect with a porter. But, boy, doesn’t that sound a lot like a stout? So what is the difference?
The distinction arose when there was a difference. In Britain in the eighteenth century, stout referred to a version of any beer that had a stronger flavor and higher alcohol content than the regular version. When porters gained popularity (it was huge by the end of the eighteenth century) stout became associated more with stronger versions of porter called porter stouts. Eventually porter was dropped, leaving us with just stouts.
History is fine, but that won’t help you at the bar when you’re trying to decide what to order. Unfortunately, we are left with another unsatisfying truth: there is no generally agreed upon, meaningful distinction between porters and stouts. Some brewers say that the line dividing present day porters and stouts is at best blurry. Others will say there is no difference, and others will say that there is a distinction, but it’s theirs, rather than universal. And that’s just the brewers. Check out a few online forums, and your head will explode, or at least hurt a lot before you’re done.
So, in lieu of the general guidelines we usually try to offer, the best we can do in this case is to recommend trying several types of each style and then deciding what kind of characteristics you prefer. You might even know without trying several that you would prefer a porter or stout that is more bitter, for example. When you are faced with a new and unfamiliar selection of porters or stouts, any good bartender should be able to offer a good recommendation based on your preferences.
May your hands-on phase of research into the world of porters and stouts be infinitely more satisfying than the truth sometimes is.