Keg

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A keg is a cylindrical container, usually constructed of aluminum, steel or wood and commonly used to store, transport, and serve beer. Other alcoholic or non-alcoholic drinks, carbonated or not carbonated, may be housed as well. These liquids are generally under pressure. The keg was introduced in the early 1960s to allow for more efficient cleaning and filling in breweries^{[citation needed]}. There are a few essential differences between a cask and a keg. The keg is built with a downtube located in its center with a valve to force gasses out when filling and air in when dispensing. Casks are simply gravity-fed for the dispensing of liquids. Also kegs have a simple concave bottom, whereas a cask is flat on the bottom. The concavity allows for sediment to not be retained in the cask. Lastly, kegs have straight sides, unlike the traditional barrel or cask shape.

From a linguistic point of view, a figal used for dispensing soft drinks is not considered to be a keg, in spite of being known as a cornelius keg.

Formerly a keg was a small barrel made by a cooper used to transport items such as nails.

Contents 1 Metrology 2 The Mini Keg 3 The Pony Keg 4 UK keg supply structure 5 Tapping a keg 6 Homebrewing kegs 6.1 Cleaning and Care 7 Keg laws 8 Games involving kegs 9 Keg hiring 10 Keg Storage 11 References 12 External links

[edit] Metrology

A keg is also a standard unit of measure, named for the container described above. A full keg is a 15.5 US gallon barrel, routinely called a half-barrel; a half keg or pony keg is called a quarter-barrel and has a volume of 7.75 US gallons. Generically a keg is a vessel smaller than a barrel, thus it is 30 gallons or smaller.^[1]

The terms half-barrel and quarter-barrel are derived from the fact that a U.S. beer barrel is legally defined as being equal to 31 U.S. gallons - note that this is not the same volume as some other units commonly known as "barrels". A 15.5 US gallon keg is also equal to:

• 12.5 Imperial gallons (UK)
• 58.67 litres
• 100 Imperial pints (UK)
• 120 US pints
• 165 12 oz drinks
• About 6.83 cases (1 case = 24 units) of 12oz cans of beer

However, beer kegs can come in many sizes:

Size (US gal)	Size (litres)	No. of 12 oz drinks	No. of 16 oz drinks	No. of 20 oz drinks	Weight of full keg (lbs)	Also known as
5	18.9	53	40	32	55-60	Home Brew / Corny Keg
5.23	19.8	56	42	33	-	Sixth Barrel
7.75	29.3	82	62	49	90	Quarter Barrel / Pony Keg
13.2	50	140	105	84	-	Import Keg
15.5	58.7	165	124	99	140 - 170	Half Barrel / Full Keg

See also barrel, firkin, kegger party.

[edit] The Mini Keg

Many beer brands are now producing a 5 liter keg. The so called "mini keg" can be obtained at most retail outlets that sell beer. The mini keg typically contains 5 liters of beer and can be conveniently stored inside the refrigerator. Some brands come with a spout and pour from the bottom via gravity; while others such as the Heineken DraughtKeg come pressurized, include a tap and pour from the top.

In Canada, Molson Canadian dubbed the mini keg "Bubba" (see photo). Thus one can go into a Liquor Store or sanctioned beer and wine store and ask for a Bubba; however, much like other brand names, it is now generally applied to all 5L mini kegs in Canada. This might cause confusion, as a company called Bubba Keg[1] is established in the USA, and appears to not be associated with Molson.

[edit] The Pony Keg

A pony keg is a beer vessel containing 7.75 U.S. gallons (29.33 liters) of fluid. It is half the size of the standard beer keg and equivalent to a quarter of a barrel. It will serve roughly 82 twelve ounce cups. The shape of a pony keg resembles that of a full-sized keg, while being much easier to move manually. However, it shares many inconveniences with the bigger kegs, such as: often requiring a deposit when purchased; needing a tap to serve the contents; and posing difficulties in determining the amount of beer remaining (weighing the keg or observing its buoyancy are common techniques). Despite this, a pony keg can be a cheap way to provide beer for a medium-sized party.

[edit] UK keg supply structure

The beer vessel supply structure in the UK is quite different, whilst the couplers for kegs have been largely standardised to sankey, grundy and interbrew, a couple of others exist such as UEC and U-Type; however these are much less common. The kegs themselves are either steel or increasingly the more lightweight aluminum variety. The standard keg size is 11 imperial gallons (50 liter/88 imperial pints approx) and the vast majority of keg beers are supplied in this keg size. There are also smaller 30 liter (54 imperial pints approx) kegs usually reserved for more specialist and or premium European beers.

A number of manufacturers also produce 22 imperial gallon (100Litre/172 imperial pints approx) kegs, however owing to their size they are not very popular as manual handling is extremely difficult, and as a result they tend to be used only for large scale events and bars with high throughput.

A further keg type exists within the UK beer industry, which is a 9 imperial gallon (72 imperial pints approx) firkin for cask ales. Whilst not strictly a keg in terms of being a pressurised vessel, the basic function as a receptacle for containing beer and out of which beer is dispensed is the same. The cask contains beer in a live form, in that the beer is still undergoing secondary fermentation up until the point of consumption and is not pasturised like 'keg' beers therefore the cask is also part of the brewing and maturation process.

[edit] Tapping a keg

There are two different types of tapping equipment that are available for kegs, party pumps and gas taps. Party pumps utilize outside air, which may introduce bacteria inside the keg, reducing the quality of the beer. Kegs operating a party pump should be used within 18-24 hours otherwise the beer will become unpalatable. Gas pumps normally use CO₂, but certain brewers require a mix of other gases (Guinness requires 25% CO₂ and 75% Nitrogen). Gas pumps can preserve a keg up to 120 days with proper refrigeration.

As with any pressurized container, a keg can cause injury, even at normal operating pressure, whether with compressed air or carbon dioxide:

"The tapping system and pressure regulator both should be equipped with a pressure relief (blow off) device. If you are not familiar with tapping equipment, consult your retailer..." (printed on an Anheuser-Busch's keg cap)

[edit] Homebrewing kegs

Homebrewers often use kegs for aging, filtering, and storing beer. These are seldom the standard kegs used by major brewers to transport draught beer to wholesalers, but instead are reconditioned Cornelius kegs (colloquially known as "cornies") that were originally manufactured to store soda - these vessels are much easier to fill, clean and maintain than standard beer kegs.

These kegs are stainless steel cylinders that hold approximately 5 U.S. gallons of liquid. The keg is filled with liquid (wort or beer) via a removable hatch on the top, which is then closed and sealed. Carbon dioxide is added to pressurize the keg via an inlet port on the top and is facilitated by gently rocking the brew back and forth. Liquid is dispensed via an outlet port attached to a tube that extends to the bottom of the keg. Pin-lock and ball-lock fittings (or posts) are the two types of couplings used on the inlet and outlet ports. Coke distrubutors used pin-lock fittings, while Pepsi distributors used ball-lock fittings. Ball-lock are most used. The pin-lock style is often referred to as a "Coke" keg or style and the ball-lock is often referred to as a "Pepsi" keg or style, though the fittings themselves are removable, serviceable, and contain interchangeable parts.[2]

Homebrewers often use 15.5 U.S. gallon kegs for boiling vessels in creating wort. The kegs are drilled for a drain at the bottom, and the top cut open to create a large stainless steel cooking kettle.

Alternatively, kegs specifically designed for home brewing are available[3]. The capacity may be matched to commercial extract brewing kits - typically 12 and 23 litres. Smaller 2.5 gallon kegs[4] are also made for ease of transporting to a function.

[edit] Cleaning and Care

All kegs may have residual pressure, and this must be vented to avoid having the valve explode and injure or kill a person as the valve shoots out. Conventional 15.5 U.S. gallon kegs have circle spring clips that can be removed to release the tap valve. Some kegs such as those used by Miller have threaded valves from Micromatic that, after venting, can be opened by lightly tapping the valve ears with a mallet or using a pry bar spun out counterclockwise. These valves then need to have the ball lock depressed while the valve head is lifted to overcome a safety. The safety prevents the valve from releasing under pressure.

It is recommended that kegs not be cleaned with bleach but instead with an iodine based cleaner^{[citation needed]}. The ball lock valves may be unscrewed using wrenches to allow further cleaning or replacement of O-rings or poppet valves.

[edit] Keg laws

Main article: Keg registration

In the U.S. as of 2005, there are 21 states and numerous localities that have keg registration laws. The laws vary widely in terms of whom they target, what their intended purpose is, and how strongly they are enforced.

[edit] Games involving kegs

There are many games that involve kegs, including keg races, keg riding and keg tossing. Keg games may or may not involve drinking as an integral part of the competition; games in which the keg is carried or thrown require the use of an empty keg.

"Keg Races" may refer to a competition in which the participants must spin around a keg a number of times, and usually consume some amount of beer, or the keg may have to be carried as an extra large "baton" in an athletic race. Another variant Keg Race, (known as "Continuous Keg" in Australia) involves large teams who attempt to drink an entire keg without ever turning off the tap. Various Universities have their own variant of the Keg Race. They commonly involve purchasing two kegs and assembling a decent sized group of people. The group is divided and each is assigned to a keg. The team which finishes their keg first wins. A relatively new, and often dangerous, keg game called "Donkey Keg" involves an empty keg being rolled down a flight of stairs. Then a person must reach the top of the stairs while attempting to duck, dodge, or jump over the keg.

In America, kegs have become synonymous with college parties, which are sometimes called "keggers". These parties, however, typically only utilize the beer inside the keg for games such as beer pong and flip cup, and do not use the empty barrel in a competitive way.

Another game popular in America is the "keg stand", in which people are held upside d own with the tap in their mouth, and try to consume beer for as long as possible.

[edit] Keg hiring

Keg hiring is the act of obtaining a keg for the purposes of consumption, typically at an event or party.

In the US and Australia the typical application of the keg hire is by using either a keg stored in a bucket of ice or water and/or the beer is passed through a beer line coil in ice to cool the beer. The beer is then usually dispensed directly from the keg via an attached tap where the beer is cooled by the bucket method, the latter method is usually dispensed by a tap on the side of an insulated cool box (which contains ice and the coil). The keg in this scenario is typically manually pumped using air (picnic pumps as described above) to pressurise the keg thereby maintaining carbonation and providing enough force to expel the beer from the keg. The kegs are not usually gas dispensed; however for more permanent setups such as home bars this is more common due to freshness issues.

In the UK the keg hiring scene is significantly less well developed and is in its infancy, this is likely to be from a number of factors such as the relatively poor weather in contrast to the US and Australia making outdoor oriented parties less popular, also due to the restrictive nature of the industry supply structure and the pronounced UK 'pub' culture. A notable difference in the UK market however is the method of dispensing which focuses on cooling the beer primarily after it leaves the keg. Because the US and Australia tend to have high ambient temperatures, keeping the keg itself cold is essential to ensure the carbon dioxide in the beer does not separate and therefore cause the beer to fob (go frothy). The UK does not usually have the same problem as temperatures are lower. By cooling outside the keg and the limited supply of ice commonly available it is common to use under bar 'flash' coolers; these operate on the same basic principle as the cool box and the coil however are electrically powered and cool a bath of water into an ice block around the coil. This provides a very tidy and effective method for dispensing cold beer.

[edit] Keg Storage

The latest development in keg storage is the Stack-Em (UK trade name) or the Pile Up (French Trade name) a patented system that allows kegs to be safely stacked allowing more barrels to be stored in a smaller area safely reducing the inherent risk of toppling and other health and safety issues surrounding the storage of kegs. Also by reducing the size of a cellar the Stack-Em can help reduce the carbon foot print of cellars due to a smaller area being cooled.

[edit] References

• "Definition of a Keg"
• "Parts of a Keg"
• "BrewBrat™ homebrew kegs"
• "Smaller home brew kegs"

1. ^ "keg".. (2004). Merriam-Webster Online Dictionary.. Retrieved on 2007-06-21. 

[edit] External links

• Brooks, Michael. "Space Bar". New Scientist, 22 December 2000
• Keg Beer Dispensing Articles and Education
• OSHA: Beverage Delivery Ergonomics
• Micromatic FAQ about Beer