Porter (beer)

Lore & Background

Porter was first mentioned in 1721, developing from the brown beer already produced across London. Publicans had previously aged and blended mild beers for customers, but porter was one of the first styles aged at the brewery and dispatched ready to drink. The innovation is attributed to Ralph Harwood at the Bell Brewhouse in Shoreditch, with the first delivery claimed to be to the Blue Last pub in Shoreditch. Early London porters were strong by modern standards; trials with the hydrometer in the 1770s recorded an original gravity of 1.071 and 6.6% ABV. Increased taxation during the Napoleonic Wars pushed gravity down to around 1.055, where it remained for the rest of the 19th century.

The large London porter breweries pioneered technological advances such as the thermometer (about 1760) and the hydrometer (1770). The hydrometer revealed that brown malt produced only about two-thirds as much fermentable material as pale malt. When malt tax increased during the Napoleonic Wars, brewers began using pale malt with added colouring. After a 1816 law allowed only malt and hops in beer, Wheeler's invention of black patent malt in 1817 enabled porter to be brewed from 95% pale malt and 5% patent malt, though most London brewers continued using some brown malt for flavour. Until about 1800, all London porter was matured in large vats for six to 18 months; later, a blend of two parts young beer to one part highly aged beer produced a similar flavour more cheaply.

Porter was first brewed in Ireland in 1776. Arthur Guinness began brewing porter in 1787 and had phased out all other beers from his St. James's Gate Brewery by 1799. In Ireland, porter was known as 'plain porter' or 'plain'. After the invention of black patent malt in 1817, Irish brewers dropped brown malt entirely, using only patent malt and pale malt, while English brewers continued using some brown malt, creating a difference in style.

Reader's Guide

Porter holds a significant place in brewing history as the first beer style to be widely exported and brewed internationally. By the end of the 18th century, it was produced across Great Britain, the Baltic states, Finland, Ireland, North America, Poland, Sweden, and Imperial Russia. The style's popularity prompted brewers to produce porters in a wide variety of strengths, from Single Stout Porter around 1.066 OG to Imperial Stout Porter at 1.095 and more. The history of stout and porter is intertwined; strong porters were marketed as 'stout porter', later shortened to 'stout'. Guinness Extra Stout was originally called 'Extra Superior Porter' and was not renamed until 1840. Today, the terms stout and porter are used by different breweries almost interchangeably to describe dark beers.

After declining in the 20th century—the last Guinness Irish porter was produced in 1974—the style saw a revival beginning in 1978 when the Penrhos microbrewery introduced a porter, following Anchor Brewing Company's bottled porter in 1974. Today, porter is produced in the Czech Republic, Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, the Russian Federation, Sweden, Ukraine, and the United States. Dozens of breweries in Britain now make porter, with Fuller's London Porter winning medals at the International Beer and Cider Competition in 1999, 2000, and 2002. In Ireland, porter remains an important style in the craft-beer scene, with many interpretations carbonated with nitrogen/carbon dioxide blends on draught.

Did You Know?

• Porter was the first beer style to be brewed around the world, reaching Ireland by the 1730s and North America by the 1740s.
• The name 'porter' is believed to have originated from its popularity with porters.
• The first delivery of porter was claimed to be to the Blue Last pub in Shoreditch.