Stout's first documented mention comes in 1677, in a manuscript now housed in the British Museum. The term was used there to describe a particularly strong beer. By the 1700s, dark beers called porters were becoming very popular. Brewers experimented with porters of different strengths. The strongest of these, containing around 7 or 8 percent alcohol by volume, were known as stout porters. The term “stout”, however, didn’t come into common use until much later. Most traditional stouts, started life being called porters. The most common trait is their rich dark color. The darkest stouts can be almost black. Stouts are made from black patent malt. This give the beer its dark color, astringent flavor, and distinctive ashy aroma.