Beer

Beer is an alcoholic beverage produced by the saccharification of starch and fermentation of the resulting sugar. The starch and saccharification enzymes are often derived from malted cereal grains, most commonly malted barley and malted wheat.[1] Most beer is also flavoured with hops, which add bitterness and act as a natural preservative, though other flavourings such as herbs or fruit may occasionally be included. The preparation of beer is called brewing. Beer is the world's most widely consumed alcoholic beverage,[2] and is the third-most popular drink overall, after water and tea.[3] It is thought by some to be the oldest fermented beverage.[4][5][6][7] 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,[8] 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.[9][10] 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 strength of beer is usually around 4% to 6% alcohol by volume (abv) although it may vary between 0.5% (de-alcoholized) and 20%, with some breweries creating examples of 40% abv and above in recent years. 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.

History

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 Neolithic or 9500 BC, when cereal was firstfarmed,^[11] and is recorded in the written history of ancient Iraq and ancient Egypt.^[12] Archaeologists speculate that beer was instrumental in the formation of civilisations.^[13]

The earliest known chemical evidence of barley beer dates to circa 3500–3100 BC from the site of Godin Tepe in the Zagros Mountains of western Iran.^[14][15] Some of the earliest Sumerian writings contain references to beer; examples include a prayer to the goddess Ninkasi, known as "The Hymn to Ninkasi",^[16] which served as both a prayer as well as a method of remembering the recipe for beer in a culture with few literate people,^[9][10] and the ancient advice (Fill your belly. Day and night make merry) to Gilgamesh, recorded in the Epic of Gilgamesh, by the ale-wife Siduri may, at least in part, have referred to the consumption of beer.^[17] The Ebla tablets, discovered in 1974 in Ebla, Syria and date back to 2500 BC, reveal that the city produced a range of beers, including one that appears to be named "Ebla" after the city.^[18] A fermented beverage using rice and fruit was made in China around 7000 BC. Unlike sake, mold was not used to saccharify the rice (amylolytic fermentation); the rice was probably prepared for fermentation by mastication or malting,^[19][20]

Almost any substance containing sugar can naturally undergo alcoholic fermentation. It is likely that many cultures, on observing that a sweet liquid could be obtained from a source of starch, independently invented beer. Bread and beer increased prosperity to a level that allowed time for development of other technologies and contributed to the building of civilizations.^{[21][22][23][24]}

Beer was spread through Europe by Germanic and Celtic tribes as far back as 3000 BC,^[25] and it was mainly brewed on a domestic scale.^[26] 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 narcotic herbs.^[27] What they did not contain was hops, as that was a later addition, first mentioned in Europe around 822 by a Carolingian Abbot^[28] and again in 1067 by Abbess Hildegard of Bingen.^[29]

At the Café by Édouard Manet

In 1516, William IV, Duke of Bavaria, adopted the Reinheitsgebot (purity law), perhaps the oldest food-quality regulation still in use in the 21st century, according to which the only allowed ingredients of beer are water, hops and barley-malt.^[30] Beer produced before theIndustrial 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 artisanal manufacture to industrial manufacture, and domestic manufacture ceased to be significant by the end of the 19th century.^[31] The development of hydrometers andthermometers 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.^[32] 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).^[33]

In 2010, China's beer consumption hit 450 million hectoliters (45 billion liters) or nearly twice that of the United States but only 5 percent sold were Premium draught beers, compared with 50 percent in France and Germany.^[34]

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 a brewery, 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 1978, allowing homebrewing to become a popular hobby.^[35]

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

Heat
exchanger

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.^[36] The mashing process takes around 1 to 2 hours,^[37] 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.^[38]

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.^[39]

The sweet wort collected from sparging is put into a kettle, or "copper", (so called because these vessels were traditionally made from copper)^[40] 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.^[41]

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.^[42]

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.^[43] 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.^[44]

Ingredients

Malted barley before roasting

The basic ingredients of beer are water; a starch source, such as malted barley, able to be saccharified (converted to sugars) then fermented (converted into alcohol and carbon dioxide); a brewer's yeast to produce the fermentation; and a flavouring such as hops.^[45] A mixture of starch sources may be used, with a secondary starch source, such as maize (corn), rice or sugar, often being termed anadjunct, especially when used as a lower-cost substitute for malted barley.^[46] Less widely used starch sources include millet, sorghumand cassava root in Africa, and potato in Brazil, and agave in Mexico, among others.^[47] 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.^[48] For example, Dublin has hard water well-suited to making stout, such as Guinness; while the Plzeň Region has soft water well-suited to making Pilsner (pale lager), such as Pilsner Urquell.^[48] 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.^[49]

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.^[50] Different roasting times and temperatures are used to produce different colours of malt from the same grain. Darker malts will produce darker beers.^[51]

Nearly all beer includes barley malt as the majority of the starch. This is because its fibrous hull remains attached to the grain during threshing. After malting, barley is milled, which finally removes the hull, breaking it into large pieces. These pieces remain with the grain during the mash, and act as a filter bed during lautering, when sweet wort is separated from insoluble grain material. Other malted and unmalted grains (including wheat, rice, oats, and rye, 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.^[52]

Hops

Main article: Hops

Hop cone in a Hallertau, Germany, hop yard

Flavouring beer is the sole major commercial use of hops.^[53] The flower of the hop bine is used as a flavouring and preservative agent in nearly all beer made today. The flowers themselves are often called "hops".

The first historical mention of the use of hops in beer was from 822 AD in monastery rules written by Adalhard the Elder, also known asAdalard of Corbie,^[31][54] though the date normally given for widespread cultivation of hops for use in beer is the thirteenth century.^[31][54]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 likewormwood would be combined into a mixture known as gruit and used as hops are now used.^[55] Some beers today, such as Fraoch' by the Scottish Heather Ales company^[56] and Cervoise Lancelot by the French Brasserie-Lancelot company,^[57] 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 the International 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 aids in "head retention",^[58][59] the length of time that a foamy head created by carbonation will last. The acidity of hops is a preservative.^[60][61]

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.^[62]

The dominant types of yeast used to make beer are the top-fermenting Saccharomyces cerevisiae and bottom-fermenting Saccharomyces uvarum.^[63] Brettanomyces fermentslambics,^[64] and Torulaspora delbrueckii ferments Bavarian weissbier.^[65]

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.^[66]

Clarifying agent

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.^[67]

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.^[68] If a beer is marked "suitable for Vegans", it was clarified either with seaweed or with artificial agents.^[69]

Production and trade

Beer Consumption by Country

Banner of a Microbrewery in the Franconian Switzerland, Germany

The Benedictine Weihenstephan Brewery in Bavaria, Germany, can trace its roots to the year 768, as a document from that year refers to a hop garden in the area paying a tithe to the monastery. The brewery was licensed by the City of Freising in 1040, and therefore is the oldest working brewery in the world.^[70] The oldest brewery with discontinuous production is the Břevnov Monastery in the Czech Republic, which was founded in 993.

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.^[32] More than 133 billion liters (35 billion gallons) are sold per year—producing total global revenues of $294.5 billion (£147.7 billion) as of 2006.^[33]

A microbrewery, or craft brewery, is a modern brewery which produces a limited amount of beer. 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 (1.8 megalitres, 396 thousand imperial gallons or 475 thousand US gallons) a year.^[71] A brewpub is a type of microbrewery that incorporates a pub or other eating establishment.

The highest density of breweries in the world, most of them microbreweries, exists in the German Region ofFranconia, especially in the district of Upper Franconia, which has about 200 breweries.^[72][73]

SABMiller became the largest brewing company in the world when it acquired Royal Grolsch, brewer of Dutch premium beer brand Grolsch.^[74] InBev was the second-largest beer-producing company in the world andAnheuser-Busch held the third spot, but after the acquisition of Anheuser-Busch by InBev, the new Anheuser-Busch InBev company is currently the largest brewer in the world.^[75]

Brewing at home is subject to regulation and prohibition in many countries. Restrictions on homebrewing were lifted in the UK in 1963,^[76] Australia followed suit in 1972,^[77] and the USA in 1978, though individual states were allowed to pass their own laws limiting production.^[78]

Beer Imports by Nation. From MIT/Harvard MIT/Harvard Atlas of Economic Complexity

Beer Exports by Nation. From MIT/Harvard MIT/Harvard Atlas of Economic Complexity

Varieties

Cropton, a typical UK microbrewery

25 litres of homebrew

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.^[79] The traditional European brewing regions—Germany, Belgium, England and the Czech Republic—have local varieties of beer.^[80]

English writer 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.^[81] Fred Eckhardt furthered Jackson's work in The Essentials of Beer Style in 1989.

Cask ale hand pumps with pump clips detailing the beers and their breweries

Top-fermented beers are most commonly produced with Saccharomyces cerevisiae, a top-fermenting yeast which clumps and rises to the surface,^[82] typically 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.^[83]

Before the introduction of hops into England from the Netherlands in the 15th century, the names "ale" and "beer" were exclusively applied to unhopped fermented beverages, the term beer being gradually shifted to describe a brew with an infusion of hops.^[84]

The word ale comes from Old English ealu (plural ealoþ), in turn from Proto-Germanic *alu (plural *aluþ), ultimately from the Proto-Indo-European base *h₂elut-, which holds connotations of "sorcery, magic, possession, intoxication".^[85][86][87] The word beer comes from Old Englishbēor, from Proto-Germanic *beuzą, probably from Proto-Indo-European *bʰeusóm, originally "brewer's yeast, beer dregs", although other theories have been provided connecting the word with Old English bēow, "barley", or Latin bibere, "to drink".^[88][89] On the currency of two words for the same thing in the Germanic languages, the 12th-century Old Icelandic poem Alvíssmál says, "Ale it is called among men, but among the gods, beer."^[90]

Real ale is the term coined by the Campaign for Real Ale (CAMRA) in 1973^[91] 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 tobottle conditioned and cask conditioned beers.

Pale Ale

Pale ale is a beer which uses a top-fermenting yeast^[92] and predominantly pale malt. It is one of the world's major beer styles.

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.^[93] This same beer later also became known as stout, though the word stout had been used as early as 1677.^[94] The history and development of stout and porter are intertwined.^[95]

Mild

Mild ale has a predominantly malty palate. It is usually dark coloured with an abv of 3% to 3.6%, although there are lighter hued milds as well as stronger examples reaching 6% abv and higher.

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).^[96] The flavour of wheat beers varies considerably, depending upon the specific style.

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.^[97]

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.^[98]

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.

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.^[99]