According to legend, English porters (luggage and cargo handlers) drank a nourishing brownish black beer blended from three beers. Harwood Brewery supposedly replicated this experience in a beer called “Entire.” Eventually the beer became synonymous with its target working-class audience.

It appears true that porter is eponymous. Porter developed from the dominant brown ales of the day. Designed to age at the brewery, porter's immense and immediate popularity led to the use of nascent industrial techniques to produce and age massive quantities of beer. Porter brewers gave us the hydrometer and spurred the development of pale and black roasted malts. The last British porters were brewed around World War II, and then the style lay moribund until American craft brewers resurrected it.

Stout, the other black beer, was born from porter as a stronger version of the beer. The original name “stout porter” was eventually shortened to stout and thus a new style was born. Over time, as with all British and Irish beer, the gravities dropped to their current levels.

The key ingredients to porters and stouts include black patent malt and pale malt. Some argue that roasted unmalted barley only belongs in stouts, but brewers used both in porters as well as stouts. To reduce roast malt's acidic bite, a boil kettle addition of calcium carbonate (chalk) replicates the naturally carbonated water of London and Dublin.