Guinness is an Irish dry beer brewed in a brewery founded by Arthur Guinness ( 1725 - 1803 ) at St James's Gate in Dublin . Guinness is produced by the Diageo Beverage Company, which is one of the most successful beer brands worldwide. Its products are fermented in nearly 50 countries, and are available in more than 120 countries. Guinness annual sales in 2011 were 850 million liters (more than 220 US gallons).

Guinness has a burning flavor that comes from barley that has been roasted or not baked. The use of roasted barley is a relatively recent development and did not become part of industrialization until the mid -twentieth century . For many years, a portion of the antique drink has been mixed with freshly brewed beer to give the sharp flavor of lactic acid . Although the taste of Guinness is still characterized by a distinct flavor, the company refused to confirm whether this type of blending is still used. The thick thin beer lid comes from mixing beer with nitrogen and carbon dioxide when poured.  Guinness beer is popular among Irish people, both in Ireland and abroad. It has seen a drop in consumption since 2001 ,  but it remains the best-selling alcoholic beverage in Ireland  as the company generates nearly 1 billion euros of drinks annually.

The company started in Dublin in 1759,  but had to relocate its headquarters to London at the start of the Anglo-Irish trade war in 1932. In 1997, Guinness merged with the Grand Metropolitan to form the multinational alcoholic company Diaggio.