Guinness stout

Guinness Stout is a brand of [ingredient=stout stout] [ingredient=beer beer] owned by Diageo and made primarily at the St. James Gate brewery in Dublin, Ireland. They also export a hopped, unfermented wort to local Guinness breweries around the world, which are then finished with local ingredients and fermented. 

Guinness was founded in 1759 by Arthur Guinness, a brewer who leased the then-abandoned St. James Gate brewery in Dublin for 9,000 years at 45 pounds a year. Originally, Guinness was an ale, and it wasn't until 1778 that they began brewing a porter, a dark style of beer popular in London. By the 1840's, they were producing three beers: Single Stout (a porter), Double Stout (a stout), and a "Foreign" stout for export. In 1886, Guinness was brewing more than one million barrels of beer a year, and thirty years later, they had more than doubled that. 

Declining sales in the 1980's led to Guinness being rebranded as a "craft" style beer, which was successful. Through the 1980's and 1990's, mergers ultimately resulted in a massive wine and spirits company called Diageo, though Guinness was created as a standalone company to preserve trademark rights. 

Guinness is made from water, barley, hops, and yeast, and is filtered, fined with isinglass (the air bladders of a fish) and pasteurized. Though Guinness is known for having a bitter-roasted coffee aroma and flavor, this is a relatively modern introduction that dates back to the mid-20th century. Some of the barley used is unmalted and roasted to provide color and flavor.

Draft Guinness and some versions of Guinness in cans are pressurized with nitrogen instead of carbon dioxide, which results in a creamy head and a fine bead, decreasing perceived acidity and enhancing texture. When poured on tap, a proper pour of Guinness should take 119.53 seconds and be done in two parts. Bottled Guinness is carbonated with carbon dioxide.

Today, there are three main types of Guinness: Draught, which is around 4% alcohol and sold in kegs, cans and bottles, Original Extra Stout, which ranges from 4-6% alcohol depending on destinatrion country, and Foreign Extra Stout, which is shipped to breweries around the world as wort, then "finished" with local ingredients to suit local tastes. Additions can include sorghum (in Nigeria), and the finished beer ranges from 5-8% alcohol. Foreign Export Stout is probably closest to what the 19th century Guinness tasted like. 

Guinness Website