A
beer tap is a
valveA valve is a device that regulates the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category....
, specifically a
tapA tap is a valve controlling release of liquids or gas. In the British Isles and most of the Commonwealth, the word is used for any everyday type of valve, particularly the fittings that control water supply to bathtubs and sinks...
, for controlling the release of
beerBeer is the world's oldest and most widely consumed alcoholic beverage and the third most popular drink overall after water and tea. It is produced by the brewing and fermentation of starches, mainly derived from cereal grains—most commonly malted barley, although wheat, maize , and rice are widely...
. While in other contexts, depending on location, a "tap" may be a "faucet", "valve" or "spigot", the use of
"tap" for beer is almost
universalUniversal may refer to:* The Universe, defined as the summation of all particles and energy that exist and the space-time in which all events occur-As a modifier:* Universal...
. This may be because the word was originally coined for the wooden valve in traditional
barrelA barrel or cask is a hollow conical container, traditionally made of vertical wooden staves and bound by wooden or metal hoops. Traditionally, the barrel was a standard size of measure referring to a set capacity or weight of a given commodity. For example, a beer barrel was originally a 36...
s. Beer served from a tap is largely known as
draught beerDraught beer has several related though slightly different understandings. Most references to draught beer are to filtered beer that has been served from a pressurised container, such as a keg or a widget can. A narrower meaning, beer that is served from a keg , but not from a can, bottle or cask,...
, though beer served from a cask is more commonly called
cask aleCask ale or cask-conditioned beer is the term for unfiltered and unpasteurised beer which is conditioned and served from a cask without additional nitrogen or carbon dioxide pressure...
, while beer from a keg may specifically be called keg beer.
There are many different types of beer or keg taps .
Almost universally in modern times, bulk beer is supplied in
kegA keg is a cylindrical container, usually constructed of aluminum, steel or wood. It is commonly used to store, transport, and serve beer. Other alcoholic or non-alcoholic drinks, carbonated or non-carbonated, may be housed in a keg as well...
s that are served with the aid of external pressure.
A
beer tap is a
valveA valve is a device that regulates the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category....
, specifically a
tapA tap is a valve controlling release of liquids or gas. In the British Isles and most of the Commonwealth, the word is used for any everyday type of valve, particularly the fittings that control water supply to bathtubs and sinks...
, for controlling the release of
beerBeer is the world's oldest and most widely consumed alcoholic beverage and the third most popular drink overall after water and tea. It is produced by the brewing and fermentation of starches, mainly derived from cereal grains—most commonly malted barley, although wheat, maize , and rice are widely...
. While in other contexts, depending on location, a "tap" may be a "faucet", "valve" or "spigot", the use of
"tap" for beer is almost
universalUniversal may refer to:* The Universe, defined as the summation of all particles and energy that exist and the space-time in which all events occur-As a modifier:* Universal...
. This may be because the word was originally coined for the wooden valve in traditional
barrelA barrel or cask is a hollow conical container, traditionally made of vertical wooden staves and bound by wooden or metal hoops. Traditionally, the barrel was a standard size of measure referring to a set capacity or weight of a given commodity. For example, a beer barrel was originally a 36...
s. Beer served from a tap is largely known as
draught beerDraught beer has several related though slightly different understandings. Most references to draught beer are to filtered beer that has been served from a pressurised container, such as a keg or a widget can. A narrower meaning, beer that is served from a keg , but not from a can, bottle or cask,...
, though beer served from a cask is more commonly called
cask aleCask ale or cask-conditioned beer is the term for unfiltered and unpasteurised beer which is conditioned and served from a cask without additional nitrogen or carbon dioxide pressure...
, while beer from a keg may specifically be called keg beer.
There are many different types of beer or keg taps .
Pressure-dispense bar tap
Almost universally in modern times, bulk beer is supplied in
kegA keg is a cylindrical container, usually constructed of aluminum, steel or wood. It is commonly used to store, transport, and serve beer. Other alcoholic or non-alcoholic drinks, carbonated or non-carbonated, may be housed in a keg as well...
s that are served with the aid of external pressure. In a normal bar dispense system, this pressure comes from a cylinder of
carbon dioxideCarbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state...
(or occasionally
nitrogenNitrogen is a chemical element that has the symbol N and atomic number 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78% by volume of Earth's atmosphere.Many industrially important...
) which forces the beer out of the keg and up a narrow tube to the bar. At the end of this tube is a valve built into a fixture (usually somewhat decorative) on the bar. This is the beer tap, and opening it with a small lever causes beer, pushed by the gas from the cylinder, to flow into the glass.
Portable keg tap
Sometimes, beer kegs designed to be connected to the above system are instead used on their own, perhaps at a party or outdoor event. In this case, a self-contained portable tap is required that allows beer to be served straight from the keg. Because the keg system uses pressure to force the beer up and out of the keg, these taps must have a means of supplying it. The typical "picnic tap" uses a hand pump to push air into the keg; this will cause the beer to spoil faster but is perfectly acceptable if the entire keg will be consumed in a short time. Portable taps with small CO
2 cylinders are also available.
Cask beer tap
Beers brewed and served by traditional methods, typically
cask aleCask ale or cask-conditioned beer is the term for unfiltered and unpasteurised beer which is conditioned and served from a cask without additional nitrogen or carbon dioxide pressure...
, do not use artificial gas. Taps for cask beer are simple on-off valves that are hammered into the end of the cask (see
keystoneA keystone is a small wooden or plastic fitting used in ale casks.For some years wooden casks have been effectively obsolete, with the majority now being aluminium or stainless steel, and a few sturdy plastic ones beginning to appear. Nevertheless, the standard tap is still designed to be hammered...
for details). When beer is served directly from the cask ("by gravity"), as at
beer festivalA Beer Festival is an organised event during which a variety of beers are available for tasting and purchase. Beer festivals are held in a number of countries...
s and some pubs, it simply flows out of the tap and into the glass. When the cask is stored in the cellar and served from the bar, as in most pubs, the beer line is screwed onto the tap and the beer is pulled through it by a
beer engineA beer engine is a device for pumping beer, originally manually operated and typically used to dispense beer from a cask or container in a pub's basement or cellar. It was invented by the locksmith and hydraulic engineer Joseph Bramah in 1797...
. The taps used are the same, and in beer-line setups the first pint is often poured from the cask as for "gravity", for tasting, before the line is connected. Cask beer taps can be brass (now discouraged for fear of lead contamination), stainless steel, plastic, and wood.
In Scotland, cask ale was traditionally served through a
tall fount. These appear similar to keg taps (indeed, many Scottish pubs serve keg beer through adapted tall founts) rendered from brass but the beer was drawn from the barrel via air pressure generated by a water engine rather than by a pressurised artificial gas. Some pubs still dispense cask beer using this method (although the water engine will invariably have been replaced by an electric compressor) but is increasingly rare due to the perception that hand-pumps are the 'correct' means by which to serve real ale, and to the potential for confusion with keg ale, which is regarded as inferior by many beer drinkers.
Temprite
In
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the continental mainland , the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans...
, there is a range of a portable and fixed beer coolers and dispensers under the trade name "Temprite". The keg beer is attached to the machine by a flexible hose, and the beer flows through a cooler system to a tap. On simple Temprites, the beer flows through copper pipes in an
iceIce is a solid phase, usually crystalline, of a non-metallic substance that is liquid or gas at room temperature, such as carbon dioxide ice , ammonia ice, or methane ice. However, the predominant use of the term ice is for water ice, technically restricted to one of the 15 known crystalline phases...
box; for more expensive models, a
refrigerationRefrigeration is the process of removing heat from an enclosed space, or from a substance, and moving it to a place where it is unobjectionable. The primary purpose of refrigeration is lowering the temperature of the enclosed space or substance and then maintaining that lower temperature.The term...
unit cools the beer. Temprites can have multiple beers using the same cooler system.
Tap traditions
For draught beer, there is a centuries old tradition that requires the delivery of the tap handle for any keg or draught beer being retired from the bar, pub, tavern, or establishment's beer list for which the tap must be removed. Upon removal it is presented to the person who consumed the last beer from the retiring beer, ale or cider.