Leffe, a Belgian beer, served in branded glasses
Schlenkerla Rauchbier straight from the cask
Weizenbier, brewed from wheat; popular in Germany
Beer is the world's oldest[1] and most
popular[2][3] alcoholic beverage. It is produced by the
fermentation of sugars derived from starch-based material — the most common being malted barley; however, wheat, corn, and rice are also widely used, usually in conjunction with the barley. Less widely used starch sources include
millet, sorghum and cassava
root in Africa, potato in Brazil, and agave in Mexico,
among others.
The starch source is steeped in water, along with certain enzymes, to produce a sugary
wort which is then flavoured with herbs, fruit or most commonly hops. Yeast
is then used to cause fermentation, which produces alcohol and other waste products
from anaerobic respiration of the sugars. The process of beer production is called
brewing.
Beer uses many varying ingredients, production methods and traditions. The type of yeast and production method may be used to
classify beer into ale, lager and spontaneously fermented beers. Some beer writers and organizations differentiate and categorize beers by various
factors into beer styles. Alcoholic beverages fermented from non-starch sources such as grape
juice (wine) or honey (mead), as well as distilled beverages, are not classified as beer.
History
-
Egyptian wooden model of beer making in ancient Egypt, Rosicrucian Egyptian Museum, San Jose, California.
Beer is one of the oldest beverages, possibly dating back to 6th millennium BCE, and is
recorded in the written history of Ancient Egypt and Mesopotamia.[4] The earliest known
chemical evidence of beer dates to circa 3500–3100 BC.[5]
As almost any substance containing carbohydrates, namely sugar 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[6][7][8].
Beer produced before the Industrial Revolution was mainly made and sold on a
domestic scale, although by the 7th century CE beer was also being produced and sold by European monasteries. During the
Industrial Revolution, the production of beer moved from artisanal manufacture to industrial
manufacture, and domestic manufacture ceased to be significant by the end of the nineteenth century.[9] The development of hydrometers and
thermometers changed brewing because they allowed the brewer more control of the brewing
process and greater knowledge of the results.
The brewing industry
Today, the brewing industry is a huge global business, consisting of several multinational companies and many thousands of smaller producers ranging from brewpubs to regional breweries. 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.[10]
The industry is dominated by a few international players[11].
The acquisition of Miller Brewing by South African Breweries to form SABMiller made it the
second-largest brewing company in 2002.
Brewing
-
Main article: Brewing
Beer is made by brewing. The essential stages of brewing are mashing, sparging, boiling, fermentation, and packaging. Most of these stages
can be accomplished in several different ways, but the purpose of each stage is the same regardless of the method used to achieve
it.
Mashing manipulates the temperature of a mixture of water and a starch source (known as mash) in order to convert
starches to fermentable sugars. The mash goes through one or more stages of being raised to a desired temperature and left at the
temperature for a period of time. During each of these stages, enzymes (alpha and beta amylase
primarily) break down the long dextrins that are present in the mash into simpler fermentable sugars, such as glucose. The number
of stages required in mashing depends on the starch source used to produce the beer. Most malted barley used today requires only
a single stage.
Sparging (a.k.a. lautering) extracts the fermentable liquid, known as
wort, from the mash. During sparging the mash is in a vessel known as a lauter-tun, which has a porous barrier through which wort but not grain can pass. The brewer allows the wort
to flow past the porous barrier and collects the wort. The brewer also adds water to the lauter-tun and lets it flow through the
mash and collects it as well. This rinses fermentable liquid from the grain in the mash and allows the brewer to gather as much
of the fermentable liquid from the mash as possible. The leftover grain is not usually further used in making the beer. However
in some places second or even third mashes would be performed with the not quite spent grains. Each run would produce a weaker
wort and thus a weaker beer.
Boiling sterilizes the wort and increases the concentration of
sugar in the wort. The wort collected from sparging is put in a kettle 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. Hops are added during boiling in order to extract bitterness, flavour and aroma from them. Hops may
be added at more than one point during the boil. As hops are boiled longer, they contribute more bitterness but less hop flavour
and aroma to the beer.
Fermentation uses yeast to turn the sugars in wort to alcohol and carbon dioxide. During fermentation, the wort becomes
beer. Once the boiled wort is cooled and in a fermenter, yeast is propagated in the wort and it is left to ferment, 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. 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.
Packaging, the fifth and final stage of the brewing process, prepares the beer for distribution and consumption. During
packaging, beer is put into the vessel from which it will be served: a keg, cask, can or bottle. Beer is carbonated in its
package, either by forcing carbon dioxide into the beer or by "natural carbonation."
Naturally carbonated beers may have a small amount of fresh wort/sugar and/or yeast added to them during packaging. This causes a
short period of fermentation which produces carbon dioxide.
Ingredients
-
Malted barley before roasting
The basic ingredients of beer are water; a fermentable starch
source, such as malted barley; and yeast. It is common for a flavouring to be added, the most popular being hops. A
mixture of starch sources may be used, with the secondary starch source, such as corn, rice and
sugar, often being termed an adjunct, especially when used as a lower cost substitute for
malted barley.
Water
Beer is composed mostly of water, and water used to make beer nearly always comes from a local source. The mineral components
of water are important to beer because minerals in the water influence the character of beer made from it. Different regions have
water with different mineral components. As a result, different regions are better suited to making certain types of beer. For
example, Dublin has hard water well-suited to making stout,
such as Guinness, and Pilzen has soft water well-suited to
making pale lager, such as Pilsner Urquell.[12] As a result, it is argued that the mineral components of
water have an influence on the character of regional beers.[13]
Starch source
The starch source in a beer provides the fermentable material in a beer and is a key determinant of the character 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. Different roasting times and temperatures are used
to produce different colours of malt from the same grain. Darker malts will produce darker beers.
Nearly all beer includes barley malt as the majority of the starch. This is because of its fibrous husk, which is important in
the sparging stage of brewing, and high concentration of amylase, a digestive enzyme which facilitates conversion of starch into sugars. Other
malted and unmalted grains (including wheat, rice, oats, and rye, and less frequently, corn and sorghum)
may be used.
Hops
-
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." The use of hops in beer was recorded by captive Jews in
Babylon[14] around 400 BCE. Hops were used by monastery
breweries, such as Corvey in Westphalia, Germany, from 822 CE,[15][16], though the date
normally given for widespread cultivation of hops for use in beer is the thirteenth century[17][18].
Hops contain several characteristics that brewers desire in beer: hops contribute a
bitterness that balances the sweetness of the malt; hops also 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 the use of hops aids in
"head retention",[19][20] the length of time that
a foamy head created by carbonation will last. The bitterness of beers is measured on the International Bitterness Units scale. Beer is the sole major commercial use of
hops.
In the past, other plants have been used for similar purposes; 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.
Yeast
-
Yeast is the microorganism that is responsible for fermentation in beer. Yeast
metabolizes 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. 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. Brettanomyces
ferments lambics, and Torulaspora
delbrueckii ferments Bavarian weissbier. 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
directly to wort.
Clarifying agent
Some brewers add one or more clarifying agents to beer. Common examples of these include
isinglass finings, obtained from swimbladders of fish; kappa carrageenan,
derived from seaweed; Irish moss, a type of red
algae; polyclar (artificial), and gelatin. Clarifying agents typically precipitate out of
the beer along with protein solids, and are found only in trace amounts in the finished product.
Types and styles of beer
-
A great many beers are brewed across the globe. Local traditions will give beers different names, giving the impression of a
multitude of different styles. However, the basics of brewing beer are shared across national and cultural boundaries.
The British beer writer Michael Jackson wrote about beers from around the
world in his 1977 book The World Guide To Beer and organised them into local style groups based on local information. This
book had an influence on homebrewers in United States
who developed an intricate system of categorising beers which is exemplified by the Beer Judge Certification Program.
The traditional European brewing regions — Germany, Belgium, the United Kingdom, Ireland, Poland, the Czech Republic, Denmark, 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.
Categorising by yeast
-
A common method of categorizing beer is by the behaviour of the yeast used in the fermentation process. In this method of
categorizing, those beers which use a fast-acting yeast, which leaves behind residual sugars, are termed ales, while those beers
which use a slower and longer acting yeast, which removes most of the sugars, leaving a clean and 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, dryer and lighter beer than ale.
Ale
-
A modern ale is commonly defined by the strain of yeast used and the fermenting temperature.
Ales are normally brewed with top-fermenting yeasts (most commonly
Saccharomyces cerevisiae) , though a number of British brewers, including Fullers and
Weltons, use ale yeast strains that have less pronounced top-fermentation
characteristics. The important distinction for ales is that they are fermented at higher temperatures and thus ferment more
quickly than lagers.
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. Typical ales have a sweeter, fuller body than lagers.
Lager
-
Lager is the English name for bottom-fermenting beers of Central European origin. They are
the most commonly consumed beers in the world. The name comes from the German
lagern ("to store"). Lagers originated from European brewers storing beer in cool cellars and caves and noticing that the
beers continued to ferment, and also to clear of sediment. Lager yeast is a bottom-fermenting yeast (e.g., Saccharomyces pastorianus), and typically undergoes
primary fermentation at 7–12 °C (45–55 °F) (the "fermentation phase"), and then is given a long secondary fermentation at 0–4 °C
(32–40 °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 "leaner" tasting beer.
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, 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.
Lambic beers: spontaneous fermentation
-
Lambic beers, a speciality of Belgian beers, use wild yeasts, rather than cultivated
ones. 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 quite common in lambics. In addition, other organisms such
as Lactobacillus bacteria produce acids which contribute to the sourness.
Pale and dark beer
The most common colour is a pale amber produced from using pale malts. Pale lager is a term used for beers made from
malt dried with coke. Coke had been first used for roasting
malt in 1642, but it wasn't until around 1703 that the term pale ale was first used.
In terms of sales volume, most of today's beer is based on the pale lager brewed in 1842
in the town of Pilsen, in the Czech Republic. The modern pale
lager is light in colour with a noticeable carbonation, 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 brands Budweiser, 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. Guinness and similar beers include roasted unmalted barley.
Serving
Draught and keg
-
Draught beer keg fonts at the Delirium 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, notably stouts, such as Guinness and "smooth" bitters, such as Boddingtons, may be served with a nitrogen/carbon dioxide mixture. Nitrogen produces fine bubbles, resulting in a dense head and a creamy
mouthfeel.
In the 1980s, Guinness introduced the beer widget, a nitrogen pressurised ball inside a
can which creates a foamy head.[21] 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.
Cask-conditioned ales
-
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 stillage and allowed to cool to cellar
temperature (typically around 13 °C / 55.4 °F), 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.
Bottles
-
Most beers are cleared of yeast by filtering when bottled. However, bottle conditioning beers retain some yeast — either by being unfiltered, or by being filtered and
then reseeded with fresh yeast. 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, in fact, 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. Alternately, the
bottle is inverted prior to opening.
Cans
-
Kannenbeer, 1900 advertisement for selling beer in sealed stone jugs
Many beers are sold in beverage cans, though there is considerable variation in the
proportion between different countries. In 2001, in Sweden 63.9% of beer was sold in cans.[22] People either drink from the can or pour the beer into a glass. Cans protect
the beer from light 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.[23]. Glass bottles are always used for bottle conditioned beers, so are associated with higher-regarded beers. Plastic (PET) bottles are used by some breweries[24].
Serving temperature
Édouard Manet's painting
The Waitress showing a woman serving beer
The temperature of a beer has an influence on a drinker's experience. Colder temperatures
allow fully attenuated beers such as pale lagers to be enjoyed for their crispness; while
warmer temperatures allow the more rounded flavours of an ale or a stout to be perceived. Beer
writer Michael Jackson proposes a five-level scale for serving temperatures:
well chilled (7 °C/45 °F) for "light" beers (pale lagers), chilled (8 °C/47 °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/60 °F) for strong dark ales (especially
trappist beer) and barley wine.
Vessels
-
Beer is drunk from a variety of vessels, such as a glass, a beer stein, a mug, a
pewter tankard, a beer
bottle or a can. Some drinkers consider that the type of vessel influences their
enjoyment of the beer. In Europe, particularly Belgium, breweries offer branded glassware intended only for their own beers.
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 of carbonation.
Beer and society
Social context
- 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. Various drinking games, such as
beer pong, and quarters are also very popular.
International consumption
- See also: Beers of the world and
Beer consumption by country
Beer is considered to be a social lubricant in many societies.[25] Beer is consumed in countries all over the world. There are breweries in Middle Eastern countries
such as Iraq and Syria as well as African countries (see African beer) and remote countries
such as Mongolia. Sales of beer are four times that of wine, the second most popular alcoholic beverage.[26][27]
Health effects
-
The moderate consumption of alcohol, including beer, has been associated with a decreased risk of cardiac disease, stroke and
cognitive decline. [28][29][30][31]
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".[32] Some sources maintain that
filtered beer loses much of its nutrition.[33][34]
A 2005 Japanese study found that low alcohol beer may possess strong anti-cancer
properties.[35] Another study found nonalcoholic beer to
mirror the cardiovascular benefits associated with moderate consumption of alcoholic beverages.[36] However, much research suggests that the primary health benefit from alcoholic
beverages comes from the alcohol they contain.[37]
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 drinking and a beer belly. But
with most overconsumption it is more a problem of improper exercise and overconsumption of carbohydrates than the product
itself.[38]
There is conclusive evidence that heavy and prolonged consumption of alcohol leads to liver disease including cirrhosis and malignancy. Heavy alcohol consumption has also been linked to pancreatitis and gout[39].
Several diet books quote beer as having the same glycemic index as maltose, a very high (and therefore undesirable) 110. Critics rejoin that beer consists mostly of water, hop
oils and only trace amounts of sugars, including maltose.[40]
Alcoholic strength
Beer ranges from less than 3% alcohol by volume (abv) to almost 30% abv. The alcohol content of beer varies by local
practice[41] or beer style. The pale lagers that most consumers are familiar with fall in the range of 4–6%, with a typical abv of
5%.[42] The customary strength of British ales is quite
low, with many session beers being around 4% abv.[43][44]
Some beers, such as tafelbier (table
beer) are of such low alcohol content (1%~4%)that they are served instead of soft drinks in some schools.[45]
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 waste 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 decrease the
effectiveness of yeasts, and consequently decrease the alcohol content.
Exceptional strength beers
Some brewers have used champagne yeasts to increase the alcohol content of their
beers. Samuel Adams reached 20% abv with Millennium[46] and then surpassed that amount to 25.6% abv with Utopias. The strongest beer sold in Britain was Delaware's Dogfish Head's World Wide Stout, a 21% abv
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