Stout and Porter - is there really a difference?
The history and development of stout and porter are intertwined. Porter was born 300 years ago, and the name is believed to be inspired by its popularity among London street and river porters. The name ‘Porter’ was first used in 1721 to describe a dark brown beer that had been made with roasted malts. Porters quickly became hugely popular and brewers started making them in a variety of strengths. The strongest among them were called "stout porters", later shortened to just ‘Stout’. This resulted in the term ‘stout’ starting to be associated with dark, rather than strong, beer.
The popularity of Porter seems to go hand-in-hand with the rise of Industrial Revolution and modern transport. It is at that time when porters started being shipped across the Channel to the North Sea and the Baltic to Eastern Europe and even China. The term Porter is alive and well in all those places, meaning a dark, roasty, usually top-fermented strong brew.
Experts may contest the point, but historically there are no differences between stout and porter. Breweries tend to differentiate the strengths of their dark beers with the "extra", "double" and "stout" labels. Recently, there is a growing tendency to describe Stouts as dry, dark beers containing a small amount of unmalted roast barley, whilst Porter means a beer flavoured with malted roast barley.
Today, stout is a relatively strong dark beer made of dark roasted malt or roasted barley, hops, water and yeast. Traditionally this term was reserved for the strongest porters, between 7-8% ABV. Most people associate stout with its dry variation, the world-renowned Guinness Draught. What’s interesting, Guinness Extra Stout was originally called Extra Superior Porter and was only given the name Extra Stout in 1840. Other famous stouts include Baltic porter, milk stout and imperial stout.