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beer
This article is about the beverage; for other meanings see beer
(disambiguation).
A selection of bottled beers
A selection of cask beersBeer is the world's oldest and most popular
alcoholic beverage. It is produced through the fermentation of starch-based
material, commonly cereal, though cassava root in Africa, potato
in Brazil, and agave in Mexico, among other starch sources, have
been used.
Only
beverages produced by this method are considered to be beer. Neither
alcoholic beverages made from the fermentation of sugars derived
from non-starch sources (e.g., grape juice or honey), nor beverages
which are distilled after fermentation should be classified as such.
Because
the ingredients and procedures used to make beer can differ, characteristics
such as taste and colour may also vary. While local names for beers
made with the same methods and ingredients may vary, the similarities
of method and ingredients can be detected to form a study of the
nature of beer styles.
History
Egyptian woman making beer (Cairo Museum)Main article: History of
beer
Beer is one of the oldest beverages humans have produced, dating
back to at least the 5th millennium BC (prior even to writing),
and recorded in the written history of Ancient Egypt and Mesopotamia.
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.
Beer
largely remained a homemaker's activity, made in the home in medieval
times. By the 14th and 15th centuries, beermaking was gradually
changing from a family-oriented activity to an artisan one, with
pubs and monasteries brewing their own beer for mass consumption.
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.
The
brewing process
For a full explanation see Brewing
Though the process of brewing beer is complex and varies considerably,
the basic stages that are consistent are outlined below. There may
be additional filtration steps between stages.
Mashing: The first phase of brewing, in which the malted grains
are crushed and soaked in warm water in order to create a malt extract.
The mash is held at constant temperature long enough for enzymes
to convert starches into fermentable sugars.
Sparging: Water is filtered through the mash to dissolve the sugars.
The darker, sugar-heavy liquid is called the wort.
Boiling: The wort is boiled along with any remaining ingredients
(excluding yeast), to remove excess water and kill any microorganisms.
The hops (whole, pelleted, or extract) are added at some stage during
the boil.
Fermentation: The yeast is added (or "pitched") and the
beer is left to ferment. After primary fermentation, the beer may
be allowed a second fermentation, which allows further settling
of yeast and other particulate matter "trub" which may
have been introduced earlier in the process. Some brewers may skip
the secondary fermentation and simply filter off the yeast.
Packaging: At this point, the beer contains alcohol, but not much
carbon dioxide. The brewer has a few options to increase carbon
dioxide levels. The most common approach by large-scale brewers
is force carbonation, via the direct addition of CO2 gas to the
keg or bottle. Smaller-scale or more classically-minded brewers
will add extra ("priming") sugar or a small amount of
newly fermenting wort ("kräusen") to the final vessel,
resulting in a short refermentation known as "cask-" or
"bottle conditioning".
After brewing, the beer is usually a finished product. At this point
the beer is kegged, casked, bottled, or canned.
Unfiltered
beers may be stored for further fermentation in conditioning tanks,
casks or bottles to allow smoothing of harsh alcohol notes, integration
of heavy hop flavours, and/or the introduction of oxidised notes
such as wine or sherry flavours. Some beer enthusiasts consider
a long conditioning period attractive for various strong beers such
as Barley wines. There are some beer cafes in Europe, such as Kulminator
in Antwerp, which stock beers aged ten years or more. Aged beers
such as Bass Kings Ale from 1902, Courage Imperial Russian Stout
and Thomas Hardys Ale are particularly valued.
Ingredients
Malted barley before roastingMain articles: Hops, Saccharomyces
cerevisiae, Brewer's yeast, Malt and Barley
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 mainly of water, which when heated is known as
brewing liquor. The characteristics of the water have an influence
on the character of the beer. Although the effect of, and interactions
between, various dissolved minerals in brewing water is complex,
as a general rule, hard water is more suited to dark beer such as
stout, while very soft water is more suited for brewing pale ale
and pale lager.
Starch
source: The most common starch source is malted cereal. And among
malts, barley malt is the most widely used owing to its high amylase
content, a digestive enzyme which facilitates the breakdown of the
starch into sugars. However, depending on what can be cultivated
locally, other malted and unmalted grains may be used, including
wheat, rice, oats, and rye, and less frequently, maize and sorghum.
Malt is formed from grain by soaking it in water, allowing it to
start to germinate, and then drying the germinated grain in a kiln.
Malting the grain produces the enzymes that will eventually convert
the 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.
Two or more types of malt may be combined.
Crushed hopsFlavourings: Hops have commonly been used as a bittering
agent in beer since the seventeenth century. Hops contain several
characteristics very favourable to beer: (a) hops contribute a bitterness
that balances the sweetness of the malt, (b) hops also contribute
aromas which range from flowery to citrus to herbal, (c) hops have
an antibiotic effect that favours the activity of brewer's yeast
over less desirable microorganisms and (d) the use of hops aids
in "head retention", the length of time that a foamy head
created by the beer's carbonation agent will last. The bitterness
of commercially-brewed beers is measured on the International Bitterness
Units scale. While hop plants are grown by farmers all around the
world in many different varieties, there is no major commercial
use for hops other than in beer.
Yeast:
is a microorganism that is responsible for fermentation. A specific
strain of yeast is chosen depending on the type of beer being produced,
the two main strains being ale yeast (Saccharomyces cerevisiae)
and lager yeast (Saccharomyces uvarum), with some other variations
available, such as brettanomyces and Torulaspora delbrueckii. Yeast
will metabolise the sugars extracted from the grains, and produce
alcohol and carbon dioxide as a result. Before yeast's functions
were understood, fermentations were conducted naturally using wild
or airborne yeasts; although a few styles such as lambics still
rely on this ancient method, most modern fermentations are conducted
using pure yeast cultures.
Clarifying
agent: Some brewers add one or more clarifying agents to beer that
are not required to be published as ingredients. Common examples
of these include Isinglass finings, obtained from swimbladders of
fish; kappa carrageenan, derived from seaweed; Irish moss, a type
of red alga; and gelatin. Since these ingredients may be derived
from animals, those concerned with the use or consumption of animal
products should obtain specific details of the filtration process
from the brewer.
Varieties
of beer
Main article: Beer style
Though there are only a few distinct types of beer, there are many
different names and style labels that attempt to categorise beers
by overall flavour and, occasionally, origin. 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
craft and home brewers in United States who developed an intricate
system of categorising beers which is exemplified by the Beer Judge
Certification Program. Outside of North America beer is mainly categorised
by strength and/or colour.
Yeast
Main
article: Brewer's yeast
A common method of categorising beer is by the behaviour of the
yeast used in the fermentation process. In this method of categorising,
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.
Ale
Main
article: Ale
Cask alesA modern ale is commonly defined by the strain of yeast
used and the fermenting temperature.
An
ale yeast is normally considered to be a top-fermenting yeast, though
a number of British brewers, such as Fullers and Weltons, use ale
yeast strains that settle at the bottom. Common features of ale
yeasts regardless of top or bottom fermentation is that they ferment
more quickly than lager yeasts, they convert less of the sugar into
alcohol (giving a sweeter, fuller body) and they produce more esters
(which give a fruity taste) and diacetyl (which gives a buttery
taste).
Ale
is typically fermented at higher temperatures than lager beer (15–23°C,
60–75°F). Ale yeasts at these temperatures produce significant
amounts of esters and other secondary flavor and aroma products,
and the result is a beer with slightly "fruity" compounds
resembling but not limited to apple, pear, pineapple, banana, plum,
or prune.
Stylistic
differences between some ales and lagers can be difficult to categorize.
Steam beer, Kölsch and some modern British Golden Summer Beers
are seen as hybrids, using 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, commonly,
lager is perceived to be cleaner tasting, dryer and lighter in the
mouth than ale.
Lager
Main
article: Lager
A glass of lagerLagers are the most commonly-consumed beer in the
world. They are of Central European origin, taking their name from
the German lagern ("to store"). Lager yeast is a bottom-fermenting
yeast, 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 (30-40°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 "crisper"
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 color, in Vienna in 1840–1841. With modern improved
fermentation control, most lager breweries use only short periods
of cold storage, typically 1–3 weeks.
Spontaneous
fermentation
Main
article: Lambic
These are beers which use wild yeasts, rather than cultivated ones.
All beers before the cultivation of yeast in the 19th century were
closer to this style, characterised by their sour flavours.
Colour
Main
article: Pale ale
Another common method of categorising beer is by colour. The colour
of a beer is determined by the malt. The most common colour is a
pale amber produced from using pale malts. Pale ale 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 volume, most of today's
beer is based on the pale lager brewed in 1842 in the town of Plzen,
in the Czech Republic. The modern Pilsner lager is light in colour
and high in carbonation, with a strong hop flavour and an alcohol
by volume content of around 5%. The Pilsner Urquell and Heineken
brands of beer are typical examples of pale lager, as are the American
brands Budweiser, Coors, and Miller.
Very
dark beers , such as stout, use very dark malts.
Draught
and keg beers
Draught beer keg fonts at the Delirium Café in BrusselsMain
articles: Draught beer, Widget (beer) and Keg beer
Draught beer from a pressurised keg is the most common dispense
method 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 has fine bubbles, producing
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. The words "draft"
and "draught" are often used as marketing terms to describe
canned or bottled beers containing a beer widget.
Cask
ales
Schlenkerla Rauchbier direct from the caskMain article: Cask ale
Cask ales are unfiltered and unpasteurised. When the landlord feels
the beer has settled, and he is ready to serve it, he will knock
a soft spile into a bunghole on the side of the cask. The major
difference in appearance between a keg and a cask is the bunghole.
A keg does not have a bunghole on the side.
The
soft spile in the bunghole allows gas to vent off. This can be seen
by the bubbles foaming around the spile. The landlord will periodically
check the bubbles by wiping the spile clean and then watching to
see how fast the bubbles reform. There still has to be some life
in the beer otherwise it will taste flat, but too much life and
the beer will taste hard or fizzy. When the beer is judged to be
ready, the landlord will replace the soft spile with a hard one
(which doesn’t allow air in or gas out) and let the beer settle
for 24 hours. He will also knock a tap into the end of the cask.
This might simply be a tap if the cask is stored behind the bar.
The beer will then be served simply under gravity pressure: turn
on the tap, and the beer comes out. But if the cask is in the cellar,
the beer needs to travel via tubes, or beer lines, up to the bar
area using a beer engine.
Bottle
conditioned beers
Main article: Bottle conditioning
Bottle conditioned beers are unfiltered and unpasteurised. It is
usually recommended that the beer is poured slowly, leaving any
yeast sediment at the bottom of the bottle. However, some drinkers
prefer to pour in the yeast, and this practise is customary with
wheat beers. Typically when serving a hefeweizen 90% of the contents
is poured and the remainder swirled to dissolve the sediment before
pouring it into the glass.
Beer
culture
Gambrinus - king of beerBeer in a social context
See
also: Pub games, Pub crawl, Public house, and Category:Drinking
culture
Various social traditions and activities are associated with beer
drinking, such as playing cards, darts or other games; or visiting
a series of different pubs in one evening. Consumption in isolation
and excess may be associated with people "drowning their sorrows,"
while drinking in excess in company may be associated with binge
drinking.
Beer
around the world
See
also: Beer and nationality and Beer consumption by country
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.
Serving
Glassware
Main article: Beer glassware
An appropriate glass is considered desirable by some beer drinkers.
Some drinkers of beer may sometimes drink straight from the bottle
or can, while others may pour their beer into a vessel before imbibing.
Drinking out of a bottle inhibits aromas picked up by the nose,
so if a drinker wishes to appreciate a beer's aroma, the beer is
first poured into a glass, mug, tankard, or stein. Some breweries
produce glassware intended for their own beers. Some aficionados
claim that the shape and material of the vessel influences the perception
of the aroma and the way in which the beer settles, similar to claims
by drinkers of brandy or cognac. Some drinkers in Britain prefer
their ale to be served in pewter tankards, while in Europe it is
common for glasses to be rinsed just before beer is poured into
them. While glass is completely non-porous, its surface can retain
oil from the skin, aerosolized oil from nearby cooking, and traces
of fat from food. When these oils come in contact with beer there
is a significant reduction in the amount of head (foam) that is
found on the beer, and the bubbles will tend to stick to the side
of the glass rather than rising to the surface as normal.
Temperature
The temperature of a beer has an influence on a drinker's experience.
Colder temperatures start to inhibit the chemical senses of the
tongue and throat, which narrow down the flavour profile of a beer,
allowing fully attenuated beers such as Pilsners and Pale lagers
to be enjoyed for their crispness, but preventing the more rounded
flavours of an ale or a stout from being perceived. While there
are no firmly agreed principles for all cases, a general approach
is that lighter coloured beers, such as Pale lagers, are usually
enjoyed cold (40-45F/4-7C), while dark, strong beers such as Imperial
Stouts are often enjoyed at cellar temperature (54-60F/12-16C) and
then allowed to warm up in the room to individual taste. Other beers
should be served at temperatures between these extremes.
Pouring
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 center 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.
Unfiltered
bottled beers may be served with the addition of the remaining yeast
at the bottom of the bottle to add both flavour and colour.
Rating
beer
Main
article: Rating beer
Rating beer is a recent craze that combines the enjoyment of beer
drinking with the hobby of collecting. People drink beer and then
record their scores and comments on various internet websites. This
is a worldwide activity and people in the USA will swap bottles
of beer with people living in New Zealand and Russia. People's scores
may be tallied together to create lists of the most popular beers
in each country as well as the most highly rated beers in the world.
Health
effects
Main
articles: Alcohol consumption and health and Beer belly
Beer contains alcohol which has a number of health risks and benefits.
However, beer includes a wide variety of other agents that are currently
undergoing scientific evaluation.
Nutritionally,
beer can contain significant amounts of magnesium, selenium, potassium,
phosphorus, biotin, and B vitamins. Typically, the darker the brew,
the more nutrient dense.
A 2005
Japanese study found that non-alcoholic beer may possess strong
anti-cancer properties. [1]. Another study found non-alcoholic beer
to mirror the cardiovascular benefits associated with moderate consumption
of alcoholic beverages. [2]
It
is considered that over-eating and lack of muscle tone is the main
cause of a beer belly, rather than beer consumption.
The
Strongest Beers In The World
Beer strength varies by local custom. British ale tends to average
4.4% abv. Belgian beers tend to average 8% abv. The strength of
the typical global pale lager is 5% abv. The yeast used for brewing
beer normally cannot get the strength much beyond 12% abv; however,
in the 1980s the Swiss brewery Hurlimann developed a yeast strain
which could get as high as 14% for their Samichlaus beer. Since
then breweries have experimented with using champagne yeasts, continually
pushing up the strength. Samuel Adams reached 20% abv with Millennium.
The strongest beer sold in Britain was Dogfish Head's World Wide
Stout, a 21% abv stout which was available from UK Safeways in 2003.
In Japan in 2005, the Hakusekikan Beer Restaurant sold an eisbock,
strengthened through freezing, believed to be 28% abv. The beer
that is considered to be the strongest yet made is Hair of the Dog's
Dave - a 29% abv barley wine made in 1994.
Related
beverages
There are a number of related beverages such as kvass, sahti and
pulque.
Africa:
Hundreds of local drinks made from millet, sorghum, and other available
starch crops.
Andes, South America: Chicha, an Andean beverage made from germinated
maize.
Bhutan, Nepal, Tibet and Sikkim: Chhaang, a popular semi-fermented
rice/millet drink in the eastern Himalaya.
China: Jiu, the word refers to all alcoholic drinks, most of which
are cheap distilled liquors (baijiu), but there are traditional
grain-based relatives of beer such as sulima, made by the Mosuo
people and Lijiang Yinjiu, made by the Nakhi people, both in the
Lijiang region of Yunnan.
Finland: Sahti, a traditional Finnish beer.
Japan: Sake, a primarily rice-based fermented drink.
Korea: Soju
Kyrgyzstan: Bozo is a low alcohol, somewhat porridgey drink made
from millet. The Kyrgyz are also fans of kumis, (in Kyrgyz called
kymyz), the fermented mare's milk drink popular in many parts of
Central Asia and Mongolia. This is very easy to obtain as it is
sold in any market and at small stands on the side of the highway
in rural areas as a source of income for the local nomads.
Mexico: Pulque, an indigenous beer made from the fermented sap of
the agave plant.
Russia/Ukraine: Kvass, a fermented non-alcoholic or mildly alcoholic
beverage.
Various regions: Rye beer, mead (made from water and honey), cider
(made from apple juice)
Some Celtic peoples of the European Iron Age drank, according to
some classical sources, a type of beer known as korma.
See also
Wikimedia Commons has media related to:
BeerWikibooks has more about this subject:
BrewingBrewery
Brewing
History of beer
Homebrewing
Category:Beer and breweries by region
Non-alcoholic beer
Reinheitsgebot - regulation concerning standards for the sale and
composition of beer
Vores Øl - An Open Source Beer
List of countries ordered by per capita beer consumption
External links
RateBeer
Beer Advocate
Cervisia in the Latin Vicipaedia, for the names of local types of
beer in Roman times
Beer Wiki
References
The Complete Guide to World Beer, Roger Protz. ISBN 1844428656.
The Barbarian's Beverage: a history of beer in ancient Europe, Max
Nelson. ISBN 0415311217.
The World Guide to Beer, Michael Jackson. ISBN 1850760004
Beer: The Story of the Pint, Martyn Cornell. ISBN 0755311655
Beer and Britannia: An Inebriated History of Britain, Peter Haydon.
ISBN 0750927488
The Book of Beer Knowledge: Essential Wisdom for the Discerning
Drinker, a Useful Miscellany, Jeff Evans. ISBN 1852491981
Country House Brewing in England, 1500-1900, Pamela Sambrook. ISBN
1852851279
Ale, Beer and Brewsters in England: Women's Work in a Changing World,
1300-1600 , Judith M. Bennett. ISBN 0195126505
A History of Beer and Brewing, I. Hornsey. ISBN 0854046305
Beer: an Illustrated History, Brian Glover. ISBN 1840385979
Beer in America: The Early Years 1587-1840 - Beer's Role in the
Settling of America and the Birth of a Nation, Gregg Smith. ISBN
0937381659
Big Book of Beer, Adrian Tierney-Jones. ISBN 1852492120
Gone for a Burton: Memories from a Great British Heritage, Bob Ricketts.
ISBN 1905203691
Farmhouse Ales: Culture and Craftsmanship in the Belgian Tradition,
Phil Marowski. ISBN 0937381845
The World Encyclopedia of Beer, Brian Glover. ISBN 0754809331
The Complete Joy of Homebrewing, Charlie Papazian ISBN 0380772876
(This is the seminal work on home brewing that is almost universally
suggested to new hobbyist)
http://en.wikipedia.org/wiki/Beer
Brewery
From Wikipedia,
the free encyclopedia
A
brewery can be a building or place that produces beer, or a business
involved in the production of beer. Breweries can take up multiple
city blocks, or be a collection of equipment in a homebrewer's kitchen.
The diversity of size in breweries is matched by the diversity of
processes, degrees of automation, and kinds of beer produced in
breweries. Typically a brewery is divided into distinct sections,
with each section reserved for one part of the brewing process.
History
A 16th century brewerySee also: History of beer
The oldest brewery in the world still in operation is believed to
be the Bavarian State-owned brewery Weihenstephan, found in the
German city of the same name, which can trace its history back to
1040. Although the Zatec brewery in Czech Republic claims it can
prove paying beer tax in 1004.
The industrialization of the brewery
Beer, in some form, can be traced back almost 5000 years to Mesopotamian
writings describing daily rations of beer and bread to workers.
Before the rise of production breweries the production of beer took
place at home and was the domain of women, as baking and brewing
were seen as "women's work". Breweries, as production
facilities reserved for making beer, did not emerge until monasteries
and other Christian institutions started producing beer not only
for their own consumption, but also to use as payment. This industrialization
of brewing shifted the responsibility of making beer to men.
Early
breweries were almost always built on multiple storeys, with equipment
on higher floors utilized earlier in the production process, so
that gravity could assist with the transfer of product from one
stage to the next. This layout is often preserved in breweries today,
but mechanical pumps allow more flexibility in brewery design.
Early
breweries typically used large copper vats in the brewhouse, and
fermentation and packaging took place in lined wooden containers.
Such breweries were common until the Industrial Revolution, when
better materials became available, and scientific advances led to
a better understanding of the brewing process. Today, almost all
breweries are made of stainless steel.
[edit]
Major technological advances
A handful of major breakthroughs have led to the modern brewery
and its ability to produce the same beer consistently.
The
steam engine, vastly improved in 1765 by James Watt, brought automatic
stirring mechanisms, and pumps into the brewery. It gave brewers
the ability to more reliably mix liquids while heating, particularly
the mash, to prevent scorching, and a quick way to transfer liquid
from one container to another. Almost all breweries now use electric-powered
stirring mechanisms and pumps. The steam engine also allowed the
brewer to make greater quantities of beer, as human power was no
longer a limiting factor in moving and stirring.
Carl
von Linde, along with several other people, is credited with developing
the refrigeration machine in 1871. Refrigeration allowed beer to
be produced year-round, and always at the same temperature. Yeast
is very sensitive to temperature, and if a beer was produced during
summer, the yeast would impart unpleasant flavors onto the beer.
Most brewers would produce enough beer during winter to last through
the summer, and store it in underground cellars, or even caves,
to protect it from summer's heat.
Most
importantly, the discovery of microbes by Louis Pasteur was instrumental
in the control of fermentation. The idea that yeast was a microorganism
that worked on wort to produce beer lead to the isolation of a single
yeast cell by Emil Christian Hansen. Pure yeast cultures allow brewers
to pick out yeasts for their fermentation characteristics, including
flavor profiles and fermentation ability. Some breweries in Belgium
still rely on "spontaneous" fermentation for their beers
(see lambic).
The modern brewery
Breweries today are made predominantly of stainless steel, although
vessels often have a decorative copper cladding for a nostalgic
look. Stainless steel has many favorable characteristics which make
it a well-suited material for brewing equipment. It imparts no flavor
in beer, it reacts with very few chemicals, which means almost any
cleaning solution can be used on it (concentrated chlorine bleach
being a notable exception) and it is very sturdy. Sturdiness is
important, as most tanks in the brewery have positive pressure applied
to them as a matter of course, and it is not unusual that a vacuum
will be formed incidentally during cleaning.
Heating
in the brewhouse is usually achieved through pressurized steam,
although direct-fire systems are not unusual in small breweries.
Similarly, cooling in other areas of the brewery is typically done
by cooling jackets on tanks, which allow the brewer to precisely
control the temperature on each tank individually, although whole-room
cooling is also common.
Today
modern brewing plants perform myriad analyses on their beers for
quality control purposes. Shipments of ingredients are analyzed
in order to correct for variations; Samples are pulled at almost
every step and tested for oxygen content, unwanted microbial infections,
and other beer-aging compounds; and a representative sample of the
finished product is often stored for months for comparison when
complaints are filed.
[edit]
The Brewing Process
Main article: Brewing
Work in the brewery is typically divided into 7 steps: Mashing,
Lautering, Boiling, Fermenting, Conditioning, Filtering, and Filling.
[edit]
Mashing
Mashing is the process of mixing milled grain (typically malted
grain) with water, and heating this mixture up with rests at certain
temperatures to allow enzymes in the malt to break down the starch
in the grain into sugars, typically maltose.
Lautering
Lautering is the separation of the extracts won during mashing from
the spent grain to create wort. It is achieved in either a Lauter
tun, a wide vessel with a false bottom, or a mash filter, a plate-and-frame
filter designed for this kind of separation. Lautering has two stages:
first wort run-off, during which the extract is separated in an
undiluted state from the spent grains, and sparging, in which extract
which remains with the grains is rinsed off with hot water.
Boiling
Boiling the wort ensures its sterility, and thus prevents a lot
of infections. During the boil, hops are added, which contribute
their bitter aromas and flavor compounds to the beer, and, along
with the heat of the boil, causes proteins in the wort to coagulate
and the pH of the wort to fall. Finally, the vapors produced during
the boil volatilize off flavors, including dimethyl sulfide precursors.
The
boil must be conducted so that is it even and intense. The boil
lasts between 60 and 120 minutes, depending on its intensity, the
hop addition schedule, and volume of wort the brewer expects to
evaporate.
Fermenting
Fermentation, as a step in the brewing process, starts as soon as
yeast is added to the cooled wort. This is also the point at which
the product is first called beer. It is during this stage that sugars
won from the malt are metabolized into alcohol and carbon dioxide.
Fermentation tanks come in all sorts of forms, from enormous tanks
which can look like storage silos, to five gallon glass carboys
in a homebrewer's closet.
Most
breweries today use cylindroconical vessels, or CCVs, have a conical
bottom and a cylindrical top. The cone's aperture is typically around
60°, an angle that will allow the yeast to flow towards the
cones apex, but is not so steep as to take up too much vertical
space. CCVs can handle both fermenting and conditioning in the same
tank. At the end of fermentation, the yeast and other solids which
have fallen to the cones apex can be simply flushed out a port at
the apex.
Open
fermentation vessels are also used, often for show in brewpubs,
and in Europe in wheat beer fermentation. These vessels have no
tops, which makes harvesting top fermenting yeasts very easy. The
open tops of the vessels make the risk of infection greater, but
with proper cleaning procedures and careful protocol about who enters
fermentation chambers when, the risk can be well controlled.
Fermentation
tanks are typically made of stainless steel. If they are simple
cylindrical tanks with beveled ends, they are arranged vertically,
as opposed to conditioning tanks which are usually laid out horizontally.
A very
few breweries still use wooden vats for fermentation as wood is
difficult to keep clean and infection-free and must be repitched
more or less yearly.
After
high kraeusen, a bung device (German: Spundapparat) is often put
on the tanks to allow the CO2 produced by the yeast to naturally
carbonate the beer. This bung device can be set to a given pressure
to match the type of beer being produced. The more pressure the
bung holds back, the more carbonated the beer becomes.
Conditioning
When the sugars in the fermenting beer have been almost completely
digested, the fermentation slows down and the yeast starts to settle
to the bottom of the tank. At this stage, the beer is cooled to
around freezing, which encourages settling of the yeast, and causes
proteins to coagulate and settle out with the yeast. Unpleasant
flavors such as phenolic compounds become insoluble in the cold
beer, and the beer's flavor becomes smoother. During this time pressure
is maintained on the tanks to prevent the beer from going flat.
If
the fermentation tanks have cooling jackets on them, as opposed
to the whole fermentation cellar being cooled, conditioning can
take place in the same tank as fermentation. Otherwise separate
tanks (in a separate cellar) must be employed.
Filtering
Filtering the beer stabilizes the flavour, and gives beer its polished
shine and brilliance. Not all beer is filtered. When tax determination
is required by local laws, it is typically done at this stage in
a calibrated tank.
Filters
come in many types. Many use pre-made filtration media such as sheets
or candles, while others use a fine powder made of, for example,
diatomaceous earth, also called kieselguhr, which is introduced
into the beer and recirculated past screens to form a filtration
bed.
Filters
range from rough filters that remove much of the yeast and any solids
(e.g. hops, grain particles) left in the beer, to filters tight
enough to strain color and body from the beer. Normally used filtration
ratings are divided into rough, fine and sterile. Rough filtration
leaves some cloudiness in the beer, but it is noticeably clearer
than unfiltered beer. Fine filtration gives a glass of beer that
you could read a newspaper through, with no noticeable cloudiness.
Finally, as its name implies, sterile filtration is fine enough
that almost all microorganisms in the beer are removed during the
filtration process.
Packaging
Packaging is putting the beer into the containers in which it will
leave the brewery. Typically this means in labelled bottles, kegs
and casks, but it might include bulk tanks for high-volume customers.
Some brewery descriptions
Skol brewery in Uran, New Bombay, India.Breweries range widely in
the volume and variety of beer produced, ranging from small breweries
that produce a few dozen barrels a year, to massive multinational
conglomerates, such as InBev, that produce hundreds of millions
of barrels annually. Some commonly used descriptions of breweries
are:
Microbrewery
– A late 20th century name for a small brewery. The term started
to be replaced with craft brewer at the start of the 21st century.
Brewpub – A brewery whose beer is brewed primarily on the
same site from which it is sold to the public, such as a pub or
restaurant. If the amount of beer that a brewpub distributes off-site
beer exceeds 75%, it may also be described as a craft or microbrewery.
Contract brewing company or contract brewery – A business
that hires another brewery to produce its beer. The contract brewing
company generally handles all of the beers marketing, sales, and
distribution, while leaving the brewing and packaging to the producer-brewery
(which, confusingly, is also sometimes referred to as a contract
brewer).
Regional brewery – An established term for a brewery that
supplies beer in a fixed geographical location. With modern distribution
methods this term is falling out of use.
Craft brewer – A term that is replacing microbrewery. A craft
brewery is a brewery which does not use adjuncts and/or is considered
to make craft beer.
Macrobrewery– A negative term for a large brewery.
A brewmaster is a person who is in charge of the production of beer.
The major breweries employ engineers with a Chemistry/Biotechnology
background. Brewmaster is here given to a person after 2½
years of extra study in the art of brewing thus earning a degree
equivalent to a Ph.D.
Craft Brewing
Before Prohibition in the United States, breweries were local institutions,
with a few exceptions. The costs involved in moving large quantities
of beer while maintaining its quality necessitated that beer be
made near where it was to be consumed. Prohibition, as could be
expected, closed most of the breweries in the United States, and
the few that were able to remain open by producing near beer, malt
extract, yeast, and other beer-related products, were in an advantageous
position to produce and sell beer after Prohibition was lifted.
During Prohibition, the advancements in refrigeration and motorvehicles
made large regional and national breweries possible. These remaining
breweries quickly became large enough to be household names all
over the nation, and concentrated mostly on the style with the broadest
appeal: American light lagers. Local breweries, with their niche
beers, were lost in America.
In
1978, Jimmy Carter signed into law a bill explicitly allowing people
to brew beer for private consumption. As the homebrewing movement
grew, homebrewers looked to re-create beers they had enjoyed in
places with a more varied beer assortment. The rise of imported
beers and homebrewing brought a demand for more beer styles, and
locally brewed beer. Answering this need, smaller breweries started
popping up across America, and a whole industry grew around the
microbrewing industry. Many of these startup microbreweries, such
as St. Paul's Summit Brewing Company, have since grown into major
regional breweries in their own right.
Portland,
Oregon has earned the name "Beervana", with more breweries
than any other city in the world. With a mind-numbing 33 breweries
just within the city limits. The McMenamin brothers alone have over
thirty brewpubs, distilleries and wineries scattered throughout
the metropolitan area, many in renovated theaters and other old
buildings otherwise destined for demolition. Other notable Portland
brewers include Widmer Brothers, Bridgeport Brewing Company and
the MacTarnahan's Brewing Company. In 1999, "beerhunter"
and author Michael Jackson called Portland a candidate for the beer
capital of the world because the city boasted more breweries than
Cologne, Germany.
The
number of craft brewers in the United States has been slowly declining
in the last decade, while craft brewers have made up a larger percentage
of beer sales in America, likely reflecting a more discriminating
customer, who is less tolerant of off flavors and poorly made beers.
See also
Brewing
Beer
Malt
Hops
Homebrewing
References
ISBN 3921690390: Technology Brewing and Malting, Wolfgang Kunze,
2nd revised edtion, VLB Berlin. Available at their website
http://www.beertown.org/craftbrewing/statistics.html: Craft Brewery
definitions at the bottom of the page
Alcohol
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Other beverages
Cocktails | Alcopop
Brewing
From Wikipedia,
the free encyclopedia
Brewing is the production of alcoholic beverages and alcohol fuel
through fermentation. This is the method used in beer production,
although the term can be used for other drinks such as sake, mead
and wine. The term is also sometimes used to refer to any chemical
mixing process.
Brewing
has a very long history, and archeological evidence tells us that
this technique was used in ancient Egypt. Descriptions of various
beer recipes can be found in Sumerian writings, some of the oldest
known writing of any sort.
The
brewing industry is part of most western economies.
Contents
[hide]
1 Brewing beer
1.1 Ale (top fermenting yeasts)
1.2 Lager (bottom fermenting yeasts)
1.3 Beers of Spontaneous Fermentation (wild yeasts)
1.4 Beers of mixed origin
2 The Brewing Process
2.1 Mashing
2.2 Lautering
2.2.1 Lauter tun
2.2.2 Mash Filter
2.3 Boiling
2.3.1 Boiling equipment
2.3.2 Energy recovery
2.3.3 Whirlpool
2.3.4 Wort cooling
2.4 Fermenting
2.5 Conditioning
2.6 Filtering
2.6.1 Sheet (pad) filters
2.6.2 Kieselguhr filters
2.7 Packaging
2.8 Secondary fermentation
3 See also
4 External links
[edit]
Brewing beer
All beers are brewed using a process based on a simple formula.
Key to the process is malted grain, depending on the region traditionally
barley, wheat or sometimes rye. (When malting rye, due care must
be taken to prevent ergot poisoning (ergotism), as rye is particularly
prone to developing this toxic fungus during the malting process.)
Malt
is made by allowing a grain to germinate, after which it is then
dried in a kiln and sometimes roasted. The germination process creates
a number of enzymes, notably a-amylase and ß-amylase, which
will be used to convert the starch in the grain into sugar. Depending
on the amount of roasting, the malt will take on dark colour and
strongly influence the colour and flavour of the beer.
The
malt is crushed to break apart the grain kernels, increase their
surface area, and separate the smaller pieces from the husks. The
resulting grist is mixed with heated water in a vat called a "mash
tun" for a process known as "mashing". During this
process, natural enzymes within the malt break down much of the
starch into sugars which play a vital part in the fermentation process.
Mashing usually takes 1 to 2 hours, and during this time various
temperature rests (waiting periods) activate different enzymes depending
upon the type of malt being used, its modification level, and the
desires of the brewmaster. The activity of these enzymes convert
the starches of the grains to dextrines and then to fermentable
sugars such as maltose. The Mash Tun generally contains a slotted
"false bottom" or other form of manifold which acts as
a strainer allowing for the separation of the liquid from the grain.
A mash
rest at 104 °F or 40 °C activates beta-glucanase, which
breaks down gummy beta-glucans in the mash, making the sugars flow
out more freely later in the process. In the modern mashing process
commercial fungal based beta-glucanase may be added as a supplement.
A mash rest from 120 °F to 130 °F (49 °C to 55 °C)
activates various proteinases, which break down proteins that might
otherwise cause the beer to be hazy. But care is of the essence
since the head on beer is also composed primarily of proteins, so
too aggressive a protein rest can result in a beer that cannot hold
a head. This rest is generally used only with undermodified (i.e.
undermalted) malts which are decreasingly popular in Germany and
the Czech Republic, or non-malted grains such as corn and rice,
which are widely used in North American beers. Finally, a mash rest
temperature of 149 to 160 °F (65 to 71 °C) is used to convert
the starches in the malt to sugar, which is then usable by the yeast
later in the brewing process. Doing the latter rest at the lower
end of the range produces more low-order sugars which are more fermentable
by the yeast. This in turn creates a beer lower in body and higher
in alcohol. A rest closer to the higher end of the range creates
more higher-order sugars which are less fermentable by the yeast,
so a fuller-bodied beer with less alcohol is the result.
After
the mashing, the resulting liquid is strained from the grains in
a process known as lautering. Prior to lautering, the mash temperature
may be raised to 165 °F to 170 °F (about 75 °C) (known
as a mashout) to deactivate enzymes. Additional water may be sprinkled
on the grains to extract additional sugars (a process known as sparging).
At
this point the liquid is known as wort (rhymes with hurt). The wort
is moved into a large tank known as a "copper" or kettle
where it is boiled with hops and sometimes other ingredients such
as herbs or sugars. The boiling process serves to terminate enzymatic
processes, precipitate proteins, isomerize hop resins, concentrate
and sterilize the wort. Hops add flavour, aroma and bitterness to
the beer. At the end of the boil, the hopped wort settles to clarify
it in a vessel called a "whirl-pool" and the clarified
wort is then cooled.
The
wort is then moved into a "fermentation vessel" where
yeast is added or "pitched" with it. The yeast converts
the sugars from the malt into alcohol, carbon dioxide and other
components through a process called Glycolysis. After a week to
three weeks, the fresh (or "green") beer is run off into
conditioning tanks. After conditioning for a week to several months,
the beer is often filtered to remove yeast and particulates. The
"bright beer" is then ready for serving or packaging.
There
are four main families of beer styles determined by the variety
of yeast used in their brewing.
Ale (top fermenting yeasts)
Ale yeasts ferment at warmer temperatures between 15°C and 20°C
(60°F to 68°F), and occasionally as high as 24°C (75°F).
Pure ale yeasts form a foam on the surface of the fermenting beer,
because of this they are often referred to as Top Fermenting yeast
- though there are some British ale yeast strains that settle at
the bottom. Ales are generally ready to drink within three weeks
after the beginning of fermentation, however, some styles benefit
from additional aging for several months or years. Ales range in
color from very pale to black opaque. England is best known for
its variety of Ales.
Lager (bottom fermenting yeasts)
While the nature of yeast was not fully understood until Emil Hansen
of the Carlsberg brewery in Denmark isolated a single yeast cell
in the 1800s, brewers in Bavaria had for centuries been selecting
these cold-fermenting Lager yeasts by storing or "Lagern"
their beers in cold alpine caves. The process of natural selection
meant that the wild yeasts that were most cold tolerant would be
the ones that would remain actively fermenting in the beer that
was stored in the caves. Some of these Bavarian yeasts were stolen
and brought back to the Carlsberg brewery around the time that Hansen
did his famous work.
Lager
yeast tends to collect at the bottom of the fermenter and is often
referred to as Bottom Fermenting yeast. Lager is fermented at much
lower temperatures, around 10°C (50°F), compared to typical
ale fermentation temperatures of 18°C (65°F). It is then
stored for 30 days or longer close to the freezing point. During
the storing or Lagering process, the beer mellows and flavours become
smoother. Sulfur components developed during fermentation dissipate.
The popularity of lager was a major factor that led to the rapid
introduction of refrigeration in the early 1900s.
Today,
lagers represent the vast majority of beers produced, the most famous
being a light lager called Pilsner which originated in Pilsen, Czech
Republic (Plzen in czech language). It is a common misconception
that all Lagers are light in color: lagers can range from very light
to deep black, just like Ales.
Beers of Spontaneous Fermentation (wild yeasts)
These beers are nowadays primarily only brewed around Brussels,
Belgium. They are fermented by means of wild yeast strains that
live in a part of the Zenne river which flows through Brussels.
These beers are also called Lambic beers. However with the advent
of yeast banks and the NCYC, brewing these beers, although not through
spontaneous fermentation, is possible anywhere.
Beers of mixed origin
These beers are blends of spontaneous fermentation beers and ales
or lagers or they are ales/lagers which are also fermented by wild
yeasts.
The Brewing Process
Work in the brewery is typically divided into 7 steps: Mashing,
Lautering, Boiling, Fermenting, Conditioning, Filtering, and Filling.
Mashing
Main article: Mashing
Mashing is the process of mixing milled grain (typically malted
grain) with water, and heating this mixture up with rests at certain
temperatures to allow enzymes in the malt to break down the starch
in the grain into sugars, typically maltose.
Boilers at the Samuel Adams brewery[edit]
Lautering
Lautering is the separation of the extracts won during mashing from
the spent grain. It is achieved in either a Lauter tun, a wide vessel
with a false bottom, or a mash filter, a plate-and-frame filter
designed for this kind of separation. Lautering has two stages:
first wort run-off, during which the extract is separated in an
undiluted state from the spent grains, and sparging, in which extract
which remains with the grains is rinsed off with hot water.
Lauter tun
A lauter tun is the traditional vessel used for separation of the
extracted wort. While the basic principle of its operation has remained
the same since its first use, technological advances have led to
better designed lauter tuns capable of quicker and more complete
extraction of the sugars from the grain.
The
false bottom in a lauter tun has thin (0.7 to 1.1 mm) slits to hold
back the solids and allow liquids to pass through. The solids, not
the false bottom, form a filtration medium and hold back small solids,
allowing the otherwise cloudy mash to run out of the lauter tun
as a clear liquid. The false bottom of a lauter tun is today made
of wedge wire, which can provide a free-flow surface of up to 12%
of the bottom of the tun.
The
run off tubes should be evenly distributed across the bottom, with
one tube servicing about 1 m² of area. Typically these tubes
have a wide, shallow cone around them to prevent drastic forces
from compacting the grain directly above the outlet. In the past
the run-off tubes flowed through swan-neck valves into a wort collection
grant. While visually stunning, this system led to a lot of oxygen
uptake. Such a system has mostly been replaced either by a central
wort-collection vessel or the arrangement of outlet ports into concentric
zones, with each zone having a ring-shaped collection pipe. Brewhouses
in plain public view, particularly those in brewpubs, often maintain
the swan-neck valves and grant for their visual effect.
A quality
lauter tun has rotating rake arms with a central drive unit. Depending
on the size of the lauter tun, there can be between two and six
rake arms. Cutting blades hang from these arms. The blade is usually
wavy and has a plough-like foot. Each blade has its own path around
the tun and the whole rake assembly can be raised and lowered. Attached
to each of these arms is a flap which can be raised and lowered
for pushing the spend grains out of the tun. The brewer, or better
yet an automated system, can raise and lower the rake arms depending
on the turbidity (cloudiness) of the run-off, and the tightness
of the grain bed, as measured by the pressure difference between
the top and bottom of the grain bed.
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