Draft Leffe (Belgian beer) in a London pub

Draught beer (also called draft beer or tap beer) is beer that has been served from, or has been conditioned in, a cask. Download high resolution version (900x1200, 118 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (900x1200, 118 KB) Wikipedia does not have an article with this exact name. ... This article is about the drink; for the village in Devon, England, see Beer, Devon. ...

The term draught beer is used because, originally, beer was pulled from casks with a hand pump. The word draught literally means "to pull". This is still widespread for real ale. In modern commercial beer dispense, the metal keg barrel is pressurized with carbon dioxide (CO₂) gas. Pressure in the keg drives the beer to the dispense faucet. Real ale is a type of beer defined by its traditional production. ...

The pressure of the CO₂ in the keg is intended to maintain the dissolved CO₂ in the beer. The CO₂ pressure varies depending on the amount of CO₂ the brewer crafted into the beer and the keg storage temperature. Occasionally the CO₂ gas is blended with Nitrogen (N₂) gas. Blending with nitrogen gas allows the keg to be pressurized above the ideal set point for 100% CO₂. Nitrogen is used because it is 80 times less soluable in water than CO₂ (it is much more difficult to 'Nitrogenate' than to 'Carbonate').

Draught beer is usually unpasteurised and therefore suffers no loss of taste due to heating of pasteurization. It should be consumed quickly after being "tapped", and is generally truer to the flavors of the ingredients as pasteurisation exposes the beer to heat and changes the flavor profile. Draught beer should be kept refrigerated between 2°C (35°F) and 4°C (40°F). Above 6°C (44°F), a beer may become wild, turn sour and cloudy in a day or two. Below 6°C (44°F), a keg of draft beer should last 20-30 days before it loses its fresh brewery taste and aroma. Pasteurization is the process of heating food for the purpose of killing harmful organisms such as bacteria, viruses, protozoa, molds, and yeasts. ...

Recently, the term has been used misleadingly to describe unpasteurized canned or bottled beers, implying that these taste and appear as cask ales. Some types of canned 'draught' beer use widgets to simulate the turbulence caused when draught beer is forced or pulled through a sparkler draught faucet (also know as a swan neck). Widget is a general-purpose term, or placeholder name, for any unspecified device, including those that have not yet been invented. ... A swan neck is a special method of dispensing beer, often using in conjunction with a sparkler. ...