Beer

Beer is the world's most widely consumed[1] and probably the oldest[2][3][4] of alcoholic beverages; it is the third
most popular drink overall, after water and tea.[5] It is produced by the brewing and fermentationof starches,
mainly derived from cereal grains—most commonly malted barley, although wheat, maize (corn), and rice are
widely used. Most beer is flavoured with hops, which add bitterness and act as a natural preservative, though
other flavourings such as herbs or fruit may occasionally be included. Some of humanity's earliest known
writings refer to the production and distribution of beer: the Code of Hammurabi included laws regulating beer
and beer parlours,[6] and "The Hymn to Ninkasi", a prayer to the Mesopotamian goddess of beer, served as
both a prayer and as a method of remembering the recipe for beer in a culture with few literate people.[7]
[8]
 Today, the brewing industry is a global business, consisting of several dominant multinational companies and
many thousands of smaller producers ranging from brewpubs to regional breweries.

The basics of brewing beer are shared across national and cultural boundaries. Beers are commonly
categorized into two main types—the globally popular pale lagers, and the regionally distinct ales,[9]which are
further categorized into other varieties such as pale ale, stout and brown ale. The strength of beer is usually
around 4% to 6% alcohol by volume (abv) though may range from less than 1% abv, to over 20% abv in rare
cases.

Beer forms part of the culture of beer-drinking nations and is associated with social traditions such as beer
festivals, as well as a rich pub culture involving activities like pub crawling and pub games such as bar billiards.

Contents
 [hide]

1 History

2 Brewing

3 Ingredients

4 Production

5 Varieties

o 5.1 Ale

o 5.2 Lag

er

6 Measurement

o 6.1 Col

our

o 6.2 Str
 ength

7 Serving

o 7.1 Dra

ught

o 7.2 Pac

kaging

o 7.3 Te

mperature

o 7.4 Ves

sels

8 Beer and

society

o 8.1 He

alth effects

9 Related

beverages

10 References

11 Bibliography

History

Main article:  History of beer

Egyptian wooden model of beer making in ancient Egypt, Rosicrucian Egyptian Museum, San Jose, California

Beer is one of the world's oldest prepared beverages, possibly dating back to the early Neolithicor 9000 BC,
and is recorded in the written history of ancient Egypt and Mesopotamia.[10] The earliest known chemical
evidence of beer dates to circa 3500–3100 BC from the site of Godin Tepe in the Zagros Mountains of
western Iran.[11] Some of the earliest Sumerian writings found in the region contain references to a type of beer;
one such example, a prayer to the goddessNinkasi, known as "The Hymn to Ninkasi", served as both a prayer
as well as a method of remembering the recipe for beer in a culture with few literate people.[7][8] The Ebla
tablets, discovered in 1974 in Ebla, Syria and date back to 2,500 BC, reveal that the city produced a range of
beers, including one that appears to be named "Ebla" after the city.[12] A beer made from rice, which, unlike
sake, didn't use the amylolytic process, and was probably prepared for fermentation by mastication or malting,
[13]
 was made in China around 7,000 BC.[14]

As almost any substance containing carbohydrates, mainly sugars or starch, can naturally undergo
fermentation, it is likely that beer-like beverages were independently invented among various cultures
throughout the world. The invention of bread and beer has been argued to be responsible for humanity's ability
to develop technology and build civilization.[15][16][17]

Beer was spread through Europe by Germanic and Celtic tribes as far back as 3000 BC,[18] and it was mainly
brewed on a domestic scale.[19] The product that the early Europeans drank might not be recognised as beer by
most people today. Alongside the basic starch source, the early European beers might contain fruits, honey,
numerous types of plants, spices and other substances such as narcoticherbs.[20] What they did not contain
was hops, as that was a later addition first mentioned in Europe around 822 by a Carolingian Abbot[21] and
again in 1067 by Abbess Hildegard of Bingen.[22]

Beer produced before the Industrial Revolution continued to be made and sold on a domestic scale, although
by the 7th century AD, beer was also being produced and sold by European monasteries. During the Industrial
Revolution, the production of beer moved from artisanalmanufacture to industrial manufacture, and domestic
manufacture ceased to be significant by the end of the 19th century.[23] The development
of hydrometers and thermometers changed brewing by allowing the brewer more control of the process and
greater knowledge of the results.

Today, the brewing industry is a global business, consisting of several dominant multinational companies and
many thousands of smaller producers ranging from brewpubs to regional breweries.[24] As of 2006, more than
133 billion liters (35 billion gallons), the equivalent of a cube 510 metres on a side, of beer are sold per year,
producing total global revenues of $294.5 billion (£147.7 billion).[25]

Brewing

Main article:  Brewing

A 16th-century brewery

The process of making beer is known as brewing. A dedicated building for the making of beer is called
abrewery, though beer can be made in the home and has been for much of its history. A company that makes
beer is called either a brewery or a brewing company. Beer made on a domestic scale for non-commercial
reasons is classified as homebrewing regardless of where it is made, though most homebrewed beer is made
in the home. Brewing beer is subject to legislation and taxation in developed countries, which from the late 19th
century largely restricted brewing to a commercial operation only. However, the UK government relaxed
legislation in 1963, followed by Australia in 1972 and the USA in 1979, allowing homebrewing to become a
popular hobby.[26]

The purpose of brewing is to convert the starch source into a sugary liquid called wort and to convert the wort
into the alcoholic beverage known as beer in a fermentation process effected by yeast.
Diagram illustrating the process of brewing beer

Hot Water Tank

Mash Tun

Malt

Hops

Copper

Hopback

Add Yeast to
Fermenter

Chiller

Bottling
 Cask or Keg

The first step, where the wort is prepared by mixing the starch source (normally malted barley) with hot water,
is known as "mashing". Hot water (known as "liquor" in brewing terms) is mixed with crushed malt or malts
(known as "grist") in a mash tun.[27] The mashing process takes around 1 to 2 hours,[28] during which the
starches are converted to sugars, and then the sweet wort is drained off the grains. The grains are now washed
in a process known as "sparging". This washing allows the brewer to gather as much of the fermentable liquid
from the grains as possible. The process of filtering the spent grain from the wort and sparge water is
called wort separation. The traditional process for wort separation is lautering, in which the grain bed itself
serves as the filter medium. Some modern breweries prefer the use of filter frames which allow a more finely
ground grist.[29] Most modern breweries use a continuous sparge, collecting the original wort and the sparge
water together. However, it is possible to collect a second or even third wash with the not quite spent grains as
separate batches. Each run would produce a weaker wort and thus a weaker beer. This process is known as
second (and third) runnings. Brewing with several runnings is called parti gyle brewing.[30]

The sweet wort collected from sparging is put into a kettle, or "copper", (so called because these vessels were
traditionally made from copper)[31] and boiled, usually for about one hour. During boiling, water in the wort
evaporates, but the sugars and other components of the wort remain; this allows more efficient use of the
starch sources in the beer. Boiling also destroys any remaining enzymes left over from the mashing
stage. Hops are added during boiling as a source of bitterness, flavour and aroma. Hops may be added at
more than one point during the boil. The longer the hops are boiled, the more bitterness they contribute, but the
less hop flavour and aroma remains in the beer.[32]

After boiling, the hopped wort is now cooled, ready for the yeast. In some breweries, the hopped wort may pass
through a hopback, which is a small vat filled with hops, to add aromatic hop flavouring and to act as a filter; but
usually the hopped wort is simply cooled for the fermenter, where the yeast is added. During fermentation, the
wort becomes beer in a process which requires a week to months depending on the type of yeast and strength
of the beer. In addition to producing alcohol, fine particulate matter suspended in the wort settles during
fermentation. Once fermentation is complete, the yeast also settles, leaving the beer clear.[33]

Fermentation is sometimes carried out in two stages, primary and secondary. Once most of the alcohol has
been produced during primary fermentation, the beer is transferred to a new vessel and allowed a period
of secondary fermentation. Secondary fermentation is used when the beer requires long storage before
packaging or greater clarity.[34] When the beer has fermented, it is packaged either into casks for cask ale or
kegs, aluminium cans, or bottles for other sorts of beer.[35]

Ingredients
Malted barley before roasting

The basic ingredients of beer are water; a starch source, such as malted barley, able to be fermented
(converted into alcohol); a brewer's yeast to produce the fermentation; and a flavouring such as hops.[36] A
mixture of starch sources may be used, with a secondary starch source, such as maize (corn), rice or sugar,
often being termed an adjunct, especially when used as a lower-cost substitute for malted barley.[37] Less
widely used starch sources includemillet, sorghum and cassava root in Africa, potato in Brazil, and agave in
Mexico, among others.[38] The amount of each starch source in a beer recipe is collectively called the grain bill.

Water

Beer is composed mostly of water. Regions have water with different mineral components; as a result, different
regions were originally better suited to making certain types of beer, thus giving them a regional character.
[39]
 For example, Dublin has hard water well suited to making stout, such as Guinness; while Pilzen has soft
water well suited to making pale lager, such as Pilsner Urquell.[39] The waters of Burton in England
contain gypsum, which benefits making pale ale to such a degree that brewers of pale ales will add gypsum to
the local water in a process known as Burtonisation.[40]

Starch source

Main articles: Malt and Mash ingredients

The starch source in a beer provides the fermentable material and is a key determinant of the strength and
flavour of the beer. The most common starch source used in beer is malted grain. Grain is malted by soaking it
in water, allowing it to begin germination, and then drying the partially germinated grain in a kiln. Malting grain
produces enzymes that convert starches in the grain into fermentable sugars.[41] Different roasting times and
temperatures are used to produce different colours of malt from the same grain. Darker malts will produce
darker beers.[42]

Nearly all beer includes barley malt as the majority of the starch. This is because of its fibrous husk, which is
not only important in the sparging stage of brewing (in which water is washed over the mashed barley grains to
form the wort), but also as a rich source of amylase, a digestive enzyme which facilitates conversion of starch
into sugars. Other malted and unmalted grains (including wheat, rice, oats, andrye, and less frequently, corn
and sorghum) may be used. In recent years, a few brewers have produced gluten-free beer made with
sorghum with no barley malt for those who cannot consume gluten-containing grains like wheat, barley, and
rye.[43]

Hops

Main article:  Hops

Flavouring beer is the sole major commercial use of hops.[44] The flower of the hop vine is used as a flavouring
and preservative agent in nearly all beer made today. The flowers themselves are often called "hops".

Hop cone in a Hallertau, Germany, hop yard

Hops were used by monastery breweries, such as Corvey in Westphalia, Germany, from AD 822,[23][45] though
the date normally given for widespread cultivation of hops for use in beer is the thirteenth century.[23][45] Before
the thirteenth century, and until the sixteenth century, during which hops took over as the dominant flavouring,
beer was flavoured with other plants; for instance, Glechoma hederacea. Combinations of various aromatic
herbs, berries, and even ingredients like wormwood would be combined into a mixture known as gruit and used
as hops are now used.[46] Some beers today, such as Fraoch' by the Scottish Heather Ales company[47] and
Cervoise Lancelot by the French Brasserie-Lancelot company,[48] use plants other than hops for flavouring.

Hops contain several characteristics that brewers desire in beer. Hops contribute a bitterness that balances the
sweetness of the malt; the bitterness of beers is measured on theInternational Bitterness Units scale. Hops
contribute floral, citrus, and herbal aromas and flavours to beer. Hops have an antibiotic effect that favours the
activity of brewer's yeast over less desirable microorganisms, and hops aids in "head retention",[49][50] the length
of time that a foamy head created by carbonation will last. The acidity of hops is a preservative.[51][52]

Yeast

Main articles: Brewer's yeast, Saccharomyces cerevisiae, and Saccharomyces uvarum

Yeast is the microorganism that is responsible for fermentation in beer. Yeast metabolises the sugars extracted
from grains, which produces alcohol and carbon dioxide, and thereby turns wort into beer. In addition to
fermenting the beer, yeast influences the character and flavour.[53] The dominant types of yeast used to make
beer are ale yeast (Saccharomyces cerevisiae) and lager yeast (Saccharomyces uvarum); their use
distinguishes ale and lager.[54] Brettanomyces ferments lambics,[55] and Torulaspora delbrueckiiferments
Bavarian weissbier.[56] Before the role of yeast in fermentation was understood, fermentation involved wild or
airborne yeasts. A few styles such as lambics rely on this method today, but most modern fermentation adds
pure yeast cultures.[57]

Clarifying agent

Main article:  Finings

Some brewers add one or more clarifying agents to beer, which typically precipitate (collect as a solid) out of
the beer along with protein solids and are found only in trace amounts in the finished product. This process
makes the beer appear bright and clean, rather than the cloudy appearance of ethnic and older styles of beer
such as wheat beers.[58]

Examples of clarifying agents include isinglass, obtained from swimbladders of fish; Irish moss, a seaweed;

kappa carrageenan, from the seaweed Kappaphycus cottonii; Polyclar (artificial); and gelatin.[59] If a beer is
marked "suitable for Vegans", it was clarified either with seaweed or with artificial agents.[60]

See also:  Vegetarianism and beer

Production

Cropton, a typical UK microbrewery

The brewing industry is a global business, consisting of several dominant multinational companies and many
thousands of smaller producers ranging from brewpubs to regional breweries.[24] More than 133 billion liters (35
billion gallons) are sold per year—producing total global revenues of $294.5 billion (£147.7 billion) in 2006.[25]
A microbrewery, or craft brewery, is a modern brewery which produces a limited amount of beer.[61] The
maximum amount of beer a brewery can produce and still be classed as a microbrewery varies by region and
by authority, though is usually around 15,000 barrels (18,000 hectolitres/ 475,000 US gallons) a year.[62] A
brewpub is a type of microbrewery that incorporates a pub or other eating establishment.

SABMiller became the largest brewing company in the world when it acquired Royal Grolsch, brewer of Dutch
premium beer brand Grolsch.[63] InBev was the second-largest beer-producing company in the world,
[64]
 and Anheuser-Busch held the third spot, but after the merger between InBev and Anheuser-Busch, the
newAnheuser-Busch InBev company is the largest brewer in the world.[65][66]

Brewing at home is subject to regulation and prohibition in many countries. Restrictions on homebrewing were
lifted in the UK in 1963,[67]Australia followed suit in 1972,[68] and the USA in 1978, though individual states were
allowed to pass their own laws limiting production.[69]

Varieties

Main article:  Beer style

Kriek, a variety of beer brewed with cherries

While there are many types of beer brewed, the basics of brewing beer are shared across national and cultural
boundaries.[70] The traditional European brewing regions—Germany, Belgium, the United
Kingdom, Ireland, Poland, the Czech Republic, Scandinavia, the Netherlands and Austria—have local varieties
of beer. In some countries, notably the USA, Canada, and Australia, brewers have adapted European styles to
such an extent that they have effectively created their own indigenous types.[71]

Despite the regional variations, beer is categorised into two main types based on the temperature of the
brewing which influences the behaviour of yeast used during the brewing process—lagers, which are brewed at
a low temperature, and the more regionally distinct ales, brewed at a higher temperature.[72]Ales are further
categorised into other varieties such as pale ale, brown or dark ale, and stout.

Michael Jackson, in his 1977 book The World Guide To Beer, categorised beers from around the world in local
style groups suggested by local customs and names.[73] Fred Eckhardt furthered Jackson's work in The
Essentials of Beer Style in 1989.

The most common method of categorising beer is by the behaviour of the yeast used in the fermentation
process. Beers using a fast acting warm fermentation which leaves behind residual sugars are termed "ales",
while beers using a slower-acting cool fermentation, with a yeast which removes most of the sugars, producing
a clean, dry beer, are termed "lagers". Differences between some ales and lagers can be difficult to
categorise. Steam beer, Kölsch, Alt, and some modern British Golden Summer Beers use elements of both
lager and ale production. Baltic Porter and Bière de Garde may be produced by either lager or ale methods or
a combination of both. However, lager production results in a cleaner-tasting, drier and lighter beer than ale.[74]

Lambic

Lambic, a beer of Belgium, is naturally fermented using wild yeasts, rather than cultivated. Many of these are
not strains of brewer's yeast (Saccharomyces cerevisiae) and may have significant differences in aroma and
sourness. Yeast varieties such as Brettanomyces bruxellensis and Brettanomyces lambicus are common in
lambics. In addition, other organisms such as Lactobacillus bacteria produce acids which contribute to the
sourness.[75]

Stout

Stout and porter are dark beers made using roasted malts or roast barley, and typically brewed with slow
fermenting yeast. There are a number of variations including Baltic porter, dry stout, and Imperial stout. The
name Porter was first used in 1721 to describe a dark brown beer popular with the street and river porters of
London.[76] This same beer later also became known as stout, though the word stout had been used as early as
1677.[77] The history and development of stout and porter are intertwined.[78]

Wheat

Wheat beer is brewed with a large proportion of wheat although it often also contains a significant proportion
of malted barley. Wheat beers are usually top-fermented (in Germany they have to be by law).[79] The flavour of
wheat beers varies considerably, depending upon the specific style.

Ale
Main article:  Ale
Cask ale hand pumps with pump clips detailing the beers and their breweries

Ales are normally brewed using a warm fermentation,[80][81] and a strain of brewers' yeast(most
commonly Saccharomyces cerevisiae) that clumps and rises to the surface;[82] because of this they are often
referred to as "top cropping" or "top fermenting"—[83] though this distinction is less clear in modern brewing with
the use of cylindro-conical tanks, where the behaviour of lager and ale yeast are quite similar. The important
distinction for ales is that they are fermented at higher temperatures and thus ferment more quickly than lagers.
[84]

Ale is typically fermented at temperatures between 15 and 24°C (60 and 75°F). At these temperatures, yeast
produces significant amounts of esters and other secondary flavour and aroma products, and the result is often
a beer with slightly "fruity" compounds resembling apple, pear, pineapple, banana, plum, or prune, among
others.[85]

Before the introduction of hops into England from the Netherlands in the 15th century, the name "ale" was
exclusively applied to unhopped fermented beverages, the term beer being gradually introduced to describe a
brew with an infusion of hops. This distinction no longer applies.[86]The word ale may come from the Old
English ealu, in turn from the Proto-Indo-European base*alut-, which holds connotations of "sorcery, magic,
possession, intoxication".[87]

Real ale is the term coined by the Campaign for Real Ale (CAMRA) in 1973[88] for "beer brewed from traditional
ingredients, matured bysecondary fermentation in the container from which it is dispensed, and served without
the use of extraneous carbon dioxide". It is applied to bottle conditioned and cask conditioned beers.

Lager
Main article:  Lager
Lager is the English name for cool fermenting beers of Central European origin. Pale lagers are the most
commonly consumed beers in the world. The name "lager" comes from the German "lagern" for "to store", as
brewers around Bavaria stored beer in cool cellars and caves during the warm summer months. These brewers
noticed that the beers continued to ferment, and to also clear of sediment, when stored in cool conditions.[89]

Lager yeast is a cool bottom-fermenting yeast (Saccharomyces pastorianus) and typically undergoes primary
fermentation at 7–12 °C (45–54 °F) (the fermentation phase), and then is given a long secondary fermentation
at 0–4 °C (32–39 °F) (the lagering phase). During the secondary stage, the lager clears and mellows. The
cooler conditions also inhibit the natural production of esters and other byproducts, resulting in a "cleaner"-
tasting beer.[90]

Modern methods of producing lager were pioneered by Gabriel Sedlmayr the Younger, who perfected dark
brown lagers at the Spaten Brewery in Bavaria, and Anton Dreher, who began brewing a lager (now known
as Vienna lager), probably of amber-red colour, in Vienna in 1840–1841. With improved modern yeast strains,
most lager breweries use only short periods of cold storage, typically 1–3 weeks.

Measurement

Main article:  Beer measurement

Beer is measured and assessed by bitterness, by strength and by colour. The perceived bitterness is measured
by the International Bitterness Units scale (IBU), defined in co-operation between the American Society of
Brewing Chemists and the European Brewery Convention.[91] The international scale was a development of the
European Bitterness Units scale, often abbreviated as EBU, and the bitterness values should be identical.[92]

Colour

Paulaner dunkel - a dark lager

Beer colour is determined by the malt.[93] The most common colour is a pale amber produced from using pale
malts. Pale lager and pale ale are terms used for beers made from malt dried with coke. Coke was first used for
roasting malt in 1642, but it was not until around 1703 that the term pale ale was used.[94][95]

In terms of sales volume, most of today's beer is based on the pale lager brewed in 1842 in the town ofPilsen in
the present-day Czech Republic.[96] The modern pale lager is light in colour with a noticeable carbonation (fizzy
bubbles) and a typical alcohol by volume content of around 5%. The Pilsner Urquell,Bitburger,
and Heineken brands of beer are typical examples of pale lager, as are the American brandsBudweiser, Coors,
and Miller.

Dark beers are usually brewed from a pale malt or lager malt base with a small proportion of darker malt added
to achieve the desired shade. Other colourants—such as caramel—are also widely used to darken beers. Very
dark beers, such as stout, use dark or patent malts that have been roasted longer. Some have roasted
unmalted barley.[97][98]

Strength
See also:  Beer measurement#By strength

Beer ranges from less than 3% alcohol by volume (abv) to around 14% abv, though this strength can be
increased to around 20% by re-pitching with champagne yeast,[99] and to 55% abv by the freeze-distilling
process.[100] The alcohol content of beer varies by local practice or beer style.[101] The pale lagers that most
consumers are familiar with fall in the range of 4–6%, with a typical abv of 5%.[102]The customary strength of
British ales is quite low, with many session beers being around 4% abv.[103] Some beers, such as table beerare
of such low alcohol content (1%–4%) that they are served instead of soft drinks in some schools.[104]

The alcohol in beer comes primarily from the metabolism of sugars that are produced during fermentation. The
quantity of fermentable sugars in the wort and the variety of yeast used to ferment the wort are the primary
factors that determine the amount of alcohol in the final beer. Additional fermentable sugars are sometimes
added to increase alcohol content, and enzymes are often added to the wort for certain styles of beer (primarily
"light" beers) to convert more complex carbohydrates (starches) to fermentable sugars. Alcohol is a by-product
of yeast metabolism and is toxic to the yeast; typical brewing yeast cannot survive at alcohol concentrations
above 12% by volume. Low temperatures and too little fermentation time decreases the effectiveness of yeasts
and consequently decreases the alcohol content.

Exceptionally strong beers

The strength of beers has climbed during the later years of the 20th century. Vetter 33, a 10.5% abv
(33 degrees Plato, hence Vetter "33")doppelbock, was listed in the 1994 Guinness Book of World Records as
the strongest beer at that time,[105][106] though Samichlaus, by the Swiss brewer Hürlimann, had also been listed
by the Guinness Book of World Records as the strongest at 14% abv.[107][108][109]Since then, some brewers have
used champagne yeasts to increase the alcohol content of their beers. Samuel Adams reached 20% abv
with Millennium,[99] and then surpassed that amount to 25.6% abv with Utopias. The strongest beer brewed in
Britain was Baz's Super Brew by Parish Brewery, a 23% abv beer.[110][111]

The product that is claimed to be the strongest beer made is The End of History, a 55% Belgian ale,[100] made
by the Scottish breweryBrewDog in 2010, who also made Sink The Bismarck!, a 41% abv IPA,[112] and Tactical
Nuclear Penguin, a 32% abv Imperial Stout; these are made using the eisbock method of freeze distilling in
which the brewery freeze distils a strong ale, gradually removing the ice and freezing again until the beer
reaches the strength required,[113][114] a process that may class the finished products as spirits rather than beer.
[115]
 The German brewery Schorschbräu's Schorschbock—a 31% abv eisbock,[116][117][118] and Hair of the
Dog's Dave—a 29% abv barley wine made in 1994, both used the same freeze distilling method.[119] A 60%
abv blend of beer with whiskey was jokily claimed as the strongest beer by a Dutch brewery in July 2010.[120][121]

Serving
Draught
Main articles: Draught beer,  Keg beer, and Cask ale

Draught beer keg fonts at the Délirium Café in Brussels

Draught beer from a pressurised keg is the most common method of dispensing in bars around the world. A
metal keg is pressurised with carbon dioxide (CO2) gas which drives the beer to the dispensing tap or faucet.
Some beers may be served with a nitrogen/carbon dioxide mixture. Nitrogen produces fine bubbles, resulting in
a dense head and a creamy mouthfeel. Some types of beer can also be found in smaller, disposable kegs
called beer balls.

In the 1980s, Guinness introduced the beer widget, a nitrogen-pressurised ball inside a can which creates a
dense, tight head, similar to beer served from a nitrogen system.[122] The words draft and draught can be used
as marketing terms to describe canned or bottled beers containing a beer widget, or which are cold-filtered
rather than pasteurised.
A selection of cask beers

Cask-conditioned ales (or cask ales) are unfiltered and unpasteurised beers. These beers are termed "real ale"
by the CAMRA organisation. Typically, when a cask arrives in a pub, it is placed horizontally on a frame called
a "stillage" which is designed to hold it steady and at the right angle, and then allowed to cool to cellar
temperature (typically between 12–14 °C / 54–57 °F),[123] before being tapped and vented—a tap is driven
through a (usually rubber) bung at the bottom of one end, and a hard spile or other implement is used to open
a hole in the side of the cask, which is now uppermost. The act of stillaging and then venting a beer in this
manner typically disturbs all the sediment, so it must be left for a suitable period to "drop" (clear) again, as well
as to fully condition—this period can take anywhere from several hours to several days. At this point the beer is
ready to sell, either being pulled through a beer line with a hand pump, or simply being "gravity-fed" directly into
the glass.

Draught beer's environmental impact can be 68% lower than bottled beer due to packaging differences.[124]
[125]
 Home brewing can reduce the environmental impact of beer via less packaging and transportation.[126] A life
cycle study of one beer brand, including grain production, brewing, bottling, distribution and waste
management, shows that the CO2 emissions from a 6-pack of micro-brew beer is about 3 kilograms (6.6
pounds).[127] The loss of natural habitat potential from the 6-pack of micro-brew beer is estimated to be 2.5
square meters (26 square feet).[128] Downstream emissions from distribution, retail, storage and disposal of
waste can be over 45% of a bottled micro-brew beer's CO2 emissions.[127] Where legal, the use of a refillable
jug, reusable bottle or other reusable containers to transport draught beer from a store or a bar, rather than
buying pre-bottled beer, can reduce the environmental impact of beer consumption.[129]

Packaging
Main articles: Beer bottle and Beverage can
A beer can with the Wikipedia logo

Most beers are cleared of yeast by filtering when packaged in bottles and cans.[130] However,bottle
conditioned beers retain some yeast—either by being unfiltered, or by being filtered and then reseeded with
fresh yeast.[131] It is usually recommended that the beer be poured slowly, leaving any yeast sediment at the
bottom of the bottle. However, some drinkers prefer to pour in the yeast; this practice is customary with wheat
beers. Typically, when serving a hefeweizen, 90% of the contents are poured, and the remainder is swirled to
suspend the sediment before pouring it into the glass. Alternatively, the bottle may be inverted prior to opening.
Glass bottles are always used for bottle conditioned beers.

Many beers are sold in cans, though there is considerable variation in the proportion between different
countries. In Sweden in 2001, 63.9% of beer was sold in cans.[132] People either drink from the can or pour the
beer into a glass. Cans protect the beer from light (thereby preventing"skunked" beer) and have a seal less
prone to leaking over time than bottles. Cans were initially viewed as a technological breakthrough for
maintaining the quality of a beer, then became commonly associated with less expensive, mass-produced
beers, even though the quality of storage in cans is much like bottles.[133] Plastic (PET) bottles are used by
some breweries.[134]

Temperature
Édouard Manet's The Waitressshowing a woman serving beer

The temperature of a beer has an influence on a drinker's experience; warmer temperatures reveal the range
of flavours in a beer but cooler temperatures are more refreshing. Most drinkers prefer pale lagerto be served
chilled, a low- or medium-strength pale ale to be served cool, while a strong barley wine orimperial stout to be
served at room temperature.[135]

Beer writer Michael Jackson proposed a five-level scale for serving temperatures: well chilled (7 °C/45 °F) for
"light" beers (pale lagers); chilled (8 °C/46 °F) for Berliner Weisse and other wheat beers; lightly chilled
(9 °C/48 °F) for all dark lagers, altbier and German wheat beers; cellar temperature (13 °C/55 °F) for regular
British ale, stout and most Belgian specialities; and room temperature (15.5 °C/59.9 °F) for strong dark ales
(especially trappist beer) and barley wine.[136]

Drinking chilled beer began with the development of artificial refrigeration and by the 1870s, was spread in
those countries that concentrated on brewing pale lager.[137] Chilling beer makes it more refreshing,[138] though
below 15.5 °C (59.9 °F) the chilling starts to reduce taste awareness[139] and reduces it significantly below 10 °C
(50 °F).[140] Beer served unchilled—either cool or at room temperature, reveal more of their flavours.[141] Cask
Marque, a non-profit UK beer organisation, has set a temperature standard range of 12°-14 °C (53°-57 °F) for
cask ales to be served.[142]

Vessels
Main article:  Beer glassware

Beer is consumed out of a variety of vessels, such as a glass, a beer stein, a mug, a pewter tankard, a beer
bottle or a can. The shape of the glass from which beer is consumed can influence the perception of the beer
and can define and accent the character of the style.[143]Breweries offer branded glassware intended only for
their own beers as a marketing promotion, as this increases sales.[144]
The pouring process has an influence on a beer's presentation. The rate of flow from the tap or other serving
vessel, tilt of the glass, and position of the pour (in the centre or down the side) into the glass all influence the
end result, such as the size and longevity of the head, lacing (the pattern left by the head as it moves down the
glass as the beer is drunk), and turbulence of the beer and its release ofcarbonation.[145]

Beer and society

A tent at Munich's Oktoberfest—the world's largest beer festival

See also:  Category:Beer culture

Various social traditions and activities are associated with beer drinking, such as playing cards, darts, or other
pub games; attending beer festivals, or visiting a series of different pubs in one evening; joining an organisation
such as CAMRA; or rating beer.[146] Various drinking games, such as beer pong, are also popular.[147]

Beer is considered to be a social lubricant in many societies,[148] and is consumed in countries all over the
world. There are breweries in Middle Eastern countries such as Iran, andSyria, as well as African countries.
Sales of beer are four times that of wine, the second most popular alcoholic beverage.[149][150] In Russia,
consumption is on the rise as younger generations are choosing beer over vodka.[151] In most societies, beer is
the most popular alcoholic beverage.

Health effects
The main active ingredient of beer is alcohol, and therefore, the health effects of alcohol apply to beer. The
moderate consumption of alcohol, including beer, is associated with a decreased risk of cardiac disease, stroke
and cognitive decline.[152][153][154][155] The long-term effects of alcohol abuse, however, include the risk of
developing alcoholism and alcoholic liver disease.
Overview of possible long-term effects of ethanol. Click to enlarge.

Brewer's yeast is known to be a rich source of nutrients; therefore, as expected, beer can contain significant
amounts of nutrients, including magnesium, selenium, potassium,phosphorus, biotin, and B vitamins. In fact,
beer is sometimes referred to as "liquid bread".[156]Some sources maintain that filtered beer loses much of its
nutrition.[157][158]

A 2005 Japanese study found that low alcohol beer may possess strong anti-cancer properties.[159] Another
study found nonalcoholic beer to mirror the cardiovascular benefits associated with moderate consumption of
alcoholic beverages.[160] However, much research suggests that the primary health benefit from alcoholic
beverages comes from the alcohol they contain.[161]

It is considered that overeating and lack of muscle tone is the main cause of a beer belly, rather than beer
consumption. A recent study, however, found a link between binge drinkingand a beer belly. But with most
overconsumption, it is more a problem of improper exercise and overconsumption of carbohydrates than the
product itself.[162] Several diet books quote beer as having an undesirably high glycemic index of 110, the same
as maltose; however, the maltose in beer undergoes metabolism by yeast during fermentation so that beer
consists mostly of water, hop oils and only trace amounts of sugars, including maltose.[163]