Hops - wikipedia

 Hops

 Jump to : navigation , search For other uses , see hop ( disambiguation ) . Hop flower in a hop yard in the Hallertau , Germany Cross-section drawing of a hop

 Hops are the flowers ( also called seed cones or strobiles ) of the hop plant Humulus lupulus . They are used primarily as a flavouring and stability agent in beer , to which they impart bitter , zesty , or citric flavours ; though they are also used for various purposes in other beverages and herbal medicine . The hop plant is a vigorous , climbing , herbaceous perennial , usually trained to grow up strings in a field called a hopfield , hop garden ( nomenclature in the South of England ) , or hop yard ( in the West Country and U.S. ) when grown commercially . Many different varieties of hops are grown by farmers around the world , with different types used for particular styles of beer .

 The first documented use of hops in beer is from the 9th century , though Hildegard of Bingen , 300 years later , is often cited as the earliest documented source . Before this period , brewers used a `` gruit '' , composed of a wide variety of bitter herbs and flowers , including dandelion , burdock root , marigold , horehound ( the old German name for horehound , Berghopfen , means `` mountain hops '' ) , ground ivy , and heather . Early documents include mention of a hop garden in the will of Charlemagne 's father , Pepin III .

 Hops are also used in brewing for their antibacterial effect over less desirable microorganisms and for purported benefits including balancing the sweetness of the malt with bitterness and a variety of flavours and aromas . Historically , traditional herb combinations for beers were believed to have been abandoned when beers made with hops were noticed to be less prone to spoilage .

 Contents

 ( hide )

 1 History

 2 World production

 2.1 Cultivation and harvest

 2.2 Migrant labor and social impact

 3 Chemical composition

 3.1 Alpha acids

 3.2 Beta acids

 3.3 Essential oils

 3.4 Flavonoids

 4 Brewing

 5 Varieties

 5.1 Breeding programs

 5.2 Noble hops

 6 Other uses

 7 Toxicity

 8 See also

 9 References

 10 External links

 History ( edit )

 The first documented hop cultivation was in 736 , in the Hallertau region of present - day Germany , although the first mention of the use of hops in brewing in that country was 1079 . However , in a will of Pepin the Short , the father of Charlemagne , hop gardens were left to the Cloister of Saint - Denis in 768 . Not until the 13th century did hops begin to start threatening the use of gruit for flavouring . Gruit was used when taxes were levied by the nobility on hops . Whichever was taxed made the brewer then quickly switch to the other . In Britain , hopped beer was first imported from Holland around 1400 , yet hops were condemned as late as 1519 as a `` wicked and pernicious weed '' . In 1471 , Norwich , England , banned use of the plant in the brewing of ale ( `` beer '' was the name for fermented malt liquors bittered with hops ; only in recent times are the words often used as synonyms ) .

 In Germany , using hops was also a religious and political choice in the early 16th century . There was no tax on hops to be paid on the Catholic church , unlike on gruit , for which the Protestant preferred hopped beer .

 Hops used in England were imported from France , Holland and Germany with import duty paid for those ; it was not until 1524 that hops were first grown in the southeast of England ( Kent ) when they were introduced as an agricultural crop by Dutch farmers . Therefore , in the hop industry there are many words which originally were Dutch words ( see oast house ) . Hops were then grown as far north as Aberdeen , near breweries for infrastructure convenience .

 According to Thomas Tusser 's 1557 Five Hundred Points of Good Husbandry :

 `` The hop for his profit I thus do exalt , It strengtheneth drink and it flavoureth malt ; And being well - brewed long kept it will last , And drawing abide , if ye draw not too fast . ''

 In England there were many complaints over the quality of imported hops , the sacks of which were often contaminated by stalks , sand or straw to increase their weight . As a result , in 1603 , King James I approved an Act of Parliament banning the practice by which `` the Subjects of this Realm have been of late years abused &c. to the Value of £ 20,000 yearly , besides the Danger of their Healths '' .

 Hop cultivation was begun in the present - day United States in 1629 by English and Dutch farmers . Before prohibition , cultivation was mainly centred around New York , California , Oregon , and Washington state . Problems with powdery mildew and downy mildew devastated New York 's production by the 1920s , and California only produces hops on a small scale .

 Hop bars were used before modern machinery was invented to make the holes for the hop poles .

 World production ( edit )

 Hops production is concentrated in moist temperate climates , with much of the world 's production occurring near the 48th parallel north . Hop plants prefer the same soils as potatoes and the leading potato - growing states in the United States are also major hops - producing areas ; however , not all potato - growing areas can produce good hops naturally : soils in the Maritime Provinces of Canada , for example , lack the boron that hops prefer . Historically , hops were not grown in Ireland , but were imported from England . In 1752 more than 500 tons of English hops were imported through Dublin alone .

 Important production centres today are the Hallertau in Germany ( more hop - growing area than any other country as of 2006 ) , the Yakima ( Washington ) and Willamette ( Oregon ) valleys , and western Canyon County , Idaho ( including the communities of Parma , Wilder , Greenleaf , and Notus ) . The principal production centres in the UK are in Kent ( which produces Kent Goldings hops ) , Herefordshire , and Worcestershire . Essentially all of the harvested hops are used in beer making .

 Early season hop growth in a hop yard in the Yakima River Valley of Washington with Mount Adams in the distance

 Hop producing country

 2012 hop output in tonnes ( t )

 Germany

 34,434

 United States

 27,782

 China

 11,000

 Czech Republic

 4,338

 Poland

 2,206

 North Korea

 2,000

 Albania

 1,650

 United Kingdom

 1,650

 Slovenia

 1,338

 Cultivation and harvest ( edit )

 A superstructure of overhead wires supports strings that in turn support bines

 Although hops are grown in most of the continental United States and Canada , cultivation of hops for commercial production requires a particular environment . As hops are a climbing plant , they are trained to grow up trellises made from strings or wires that support the plants and allow them significantly greater growth with the same sunlight profile . In this way , energy that would have been required to build structural cells is also freed for crop growth .

 The hop plant 's reproduction method is that male and female flowers develop on separate plants , although occasionally a fertile individual will develop which contains both male and female flowers . Because pollinated seeds are undesirable for brewing beer , only female plants are grown in hop fields , thus preventing pollination . Female plants are propagated vegetatively , and male plants are culled if plants are grown from seeds .

 Hop plants are planted in rows about 2 to 2.5 metres ( 7 to 8 ft ) apart . Each spring , the roots send forth new bines that are started up strings from the ground to an overhead trellis . The cones grow high on the bine , and in the past , these cones were picked by hand . Harvesting of hops became much more efficient with the invention of the mechanical hops separator , patented by Emil Clemens Horst in 1909 .

 Harvest comes near the end of summer when the bines are pulled down and the flowers are taken to a hop house or oast house for drying . Hop houses are two - story buildings , of which the upper story has a slatted floor covered with burlap . Here the flowers are poured out and raked even . A heating unit on the lower floor is used to dry the hops . When dry , the hops are moved to a press , a sturdy box with a plunger . Two long pieces of burlap are laid into the hop press at right angles , the hops are poured in and compressed into bales .

 Hop cones contain different oils , such as lupulin , a yellowish , waxy substance , an oleoresin , that imparts flavour and aroma to beer . Lupulin contains lupulone and humulone , which possess antibiotic properties , suppressing bacterial growth favoring brewer 's yeast to grow . After lupulin has been extracted in the brewing process the papery cones are discarded .

 Migrant labor and social impact ( edit )

 Hops harvest in the Kingdom of Bohemia ( 1898 ) Hops harvest in Skåne , Sweden in 1937

 The need for massed labor at harvest time meant hop - growing had a big social impact . Around the world , the labor - intensive harvesting work involved large numbers of migrant workers who would travel for the annual hop harvest . Whole families would partake and live in hoppers ' huts , with even the smallest children helping in the fields . The final chapters of W. Somerset Maugham 's Of Human Bondage and a large part of George Orwell 's A Clergyman 's Daughter contain a vivid description of London families participating in this annual hops harvest . In England , many of those picking hops in Kent were from eastern areas of London . This provided a break from urban conditions that was spent in the countryside . People also came from Birmingham and other Midlands cities to pick hops in the Malvern area of Worcestershire . Some photographs have been preserved .

 Particularly in Kent , because of a shortage of small - denomination coin of the realm , many growers issued their own currency to those doing the labor . In some cases , the coins issued were adorned with fanciful hops images , making them quite beautiful .

 In the US , Prohibition had a major impact on hops productions , but remnants of this significant industry in West and Northwest US are still noticeable in the form of old hop kilns that survive throughout Sonoma County , among others . Florian Dauenhauer , of Santa Rosa in Sonoma County , became a manufacturer of hop - harvesting machines in 1940 , in part because of the hop industry 's importance to the county . This mechanization helped destroy the local industry by enabling large - scale mechanized production , which moved to larger farms in other areas . Dauenhauer Manufacturing remains a current producer of hop harvesting machines .

 Chemical composition ( edit )

 In addition to water , cellulose , and various proteins , the chemical composition of hops consists of compounds important for imparting character to beer .

 Alpha acids ( edit )

 Isomerization scheme of humulone

 Probably the most important chemical compound within hops are the alpha acids or humulones . During wort boiling , the humulones are thermally isomerized into iso - alpha acids or isohumulones , which are responsible for the bitter taste of beer .

 Beta acids ( edit )

 Structure of lupulone ( beta acid )

 Hops contain beta acids or lupulones sensitive to oxidative decomposition which may be detrimental to the taste of beer . For this reason , beta acids are considered a negative factor in brewing and many brewers usually choose hops with a low beta acid content .

 Essential oils ( edit )

 The main components of hops essential oils are terpene hydrocarbons consisting of myrcene , humulene and caryophyllene . Myrcene is responsible for the pungent smell of fresh hops . Humulene and its oxidative reaction products may give beer its prominent hop aroma . Together , myrcene , humulene , and caryophyllene represent 80 to 90 % of the total hops essential oil .

 Flavonoids ( edit )

 Chemical structure of 8 - prenylnaringenin

 Xanthohumol is the principal flavonoid in hops . The other well - studied prenylflavonoids are 8 - prenylnaringenin and isoxanthohumol . Xanthohumol is under basic research for its potential properties , while 8 - prenylnaringenin is a potent phytoestrogen .

 Brewing ( edit )

 Hops are used for beer brewing . The sample at the brewery Moscow Brewing Company .

 Hops are usually dried in an oast house before they are used in the brewing process . Undried or `` wet '' hops are sometimes ( since ca. 1990 ) used .

 The wort ( sugar - rich liquid produced from malt ) is boiled with hops before it is cooled down and yeast is added , to start fermentation .

 The effect of hops on the finished beer varies by type and use , though there are two main hop types : bittering and aroma . Bittering hops have higher concentrations of alpha acids , and are responsible for the large majority of the bitter flavour of a beer . European ( so - called `` noble '' ) hops typically average 5 -- 9 % alpha acids by weight ( AABW ) , and the newer American cultivars typically range from 8 -- 19 % AABW . Aroma hops usually have a lower concentration of alpha acids ( ~ 5 % ) and are the primary contributors of hop aroma and ( nonbitter ) flavour . Bittering hops are boiled for a longer period of time , typically 60 -- 90 minutes , to maximize the isomerization of the alpha acids . They often have inferior aromatic properties , as the aromatic compounds evaporate off during the boil .

 The degree of bitterness imparted by hops depends on the degree to which alpha acids are isomerized during the boil , and the impact of a given amount of hops is specified in International Bitterness Units . Unboiled hops are only mildly bitter . On the other hand , the nonbitter flavour and aroma of hops come from the essential oils , which evaporate during the boil .

 Aroma hops are typically added to the wort later to prevent the evaporation of the essential oils , to impart `` hop taste '' ( if during the final 30 minutes of boil ) or `` hop aroma '' ( if during the final 10 minutes , or less , of boil ) . Aroma hops are often added after the wort has cooled and while the beer ferments , a technique known as `` dry hopping '' , which contributes to the hop aroma . Farnesene is a major component in some hops . The composition of hop essential oils can differ between varieties and between years in the same variety , having a significant influence on flavour and aroma .

 Today , a substantial amount of `` dual - use '' hops are used , as well . These have high concentrations of alpha acids and good aromatic properties . These can be added to the boil at any time , depending on the desired effect . Hop acids also contribute to and stabilize the foam qualities of beer .

 Flavours and aromas are described appreciatively using terms which include `` grassy '' , `` floral '' , `` citrus '' , `` spicy '' , `` piney '' , `` lemony '' , `` grapefruit '' , and `` earthy '' . Many pale lagers have fairly low hop influence , while lagers marketed as Pilsener or brewed in the Czech Republic may have noticeable noble hop aroma . Certain ales ( particularly the highly hopped style known as India Pale Ale , or IPA ) can have high levels of hop bitterness .

 Brewers may use software tools to control the bittering levels in the boil and adjust recipes to account for a change in the hop bill or seasonal variations in the crop that may lead to the need to compensate for a difference in alpha acid contribution . Data may be shared with other brewers via BeerXML allowing the reproduction of a recipe allowing for differences in hop availability .

 Varieties ( edit )

 Main article : List of hop varieties

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 Breeding programs ( edit )

 There are many different varieties of hops used in brewing today . Historically , hops varieties were identified by geography ( such as Hallertau , Spalt , and Tettnang from Germany ) , by the farmer who is recognized as first cultivating them ( such as Goldings or Fuggles from England ) , or by their growing habit ( e.g. , Oregon Cluster ) .

 Around 1900 , a number of institutions began to experiment with breeding specific hop varieties . The breeding program at Wye College in Wye , Kent was started in 1904 and rose to prominence through the work of Prof. E.S. Salmon . Salmon released Brewer 's Gold and Brewer 's Favorite for commercial cultivation in 1934 , and went on to release more than two dozen new cultivars before his death in 1959 . Brewer 's Gold has become the ancestor of the bulk of new hop releases around the world since its release .

 Wye College continued its breeding program and again received attention in the 1970s , when Dr. Ray A. Neve released Wye Target , Wye Challenger , Wye Northdown , Wye Saxon and Wye Yeoman . More recently , Wye College and its successor institution Wye Hops Ltd. , have focused on breeding the first dwarf hop varieties , which are easier to pick by machine and far more economical to grow . Wye College have also been responsible for breeding hop varieties that will grow with only 12 hours of daily light for the South African hop farmers . Wye College was closed in 2009 but the legacy of their hop breeding programs , particularly that of the dwarf varieties , is continuing as already the U.S.A. private and public breeding programs are using their stock material .

 Particular hop varieties are associated with beer regions and styles , for example pale lagers are usually brewed with European ( often German , Polish or Czech ) noble hop varieties such as Saaz , Hallertau and Strissel Spalt . British ales use hop varieties such as Fuggles , Goldings and W.G.V. North American beers often use Cascade hops , Columbus hops , Centennial hops , Willamette , Amarillo hops and about forty more varieties as the U.S.A. have lately been the more significant breeders of new hop varieties , including dwarf hop varieties .

 Hops from New Zealand , such as Pacific Gem , Motueka and Nelson Sauvin , are used in a `` Pacific Pale Ale '' style of beer with increasing production in 2014 .

 Noble hops ( edit )

 Mature hops growing in a hop yard in Germany

 The term `` noble hops '' traditionally refers to varieties of hops which are low in bitterness and high in aroma . They are the European cultivars or races Hallertau , Tettnanger , Spalt , and Saaz .

 Their low relative bitterness but strong aroma are often distinguishing characteristics of European - style lagers , such as Pilsener , Dunkel , and Oktoberfest / Märzen . In beer , they are considered aroma hops ( as opposed to bittering hops ) ; see Pilsner Urquell as a classic example of the Bohemian Pilsener style , which showcases noble hops .

 As with grapes , the location where hops are grown affects the hops ' characteristics . Much as Dortmunder beer may within the EU be labelled `` Dortmunder '' only if it has been brewed in Dortmund , noble hops may officially be considered `` noble '' only if they were grown in the areas for which the hop varieties ( races ) were named .

 Hallertau or Hallertauer -- The original German lager hop ; named after Hallertau or Holledau region in central Bavaria . Due to susceptibility to crop disease , it was largely replaced by Hersbrucker in the 1970s and 1980s . ( Alpha acid 3.5 -- 5.5 % / beta acid 3 -- 4 % )

 Žatec ( Saaz ) -- Noble hop , named after Žatec town , used extensively in Bohemia to flavour pale Czech lagers such as Pilsner Urquell . Soft aroma and bitterness . ( Alpha acid 3 -- 4.5 % / Beta acid 3 -- 4.5 % )

 Spalt -- Traditional German noble hop from the Spalter region south of Nuremberg . With a delicate , spicy aroma . ( Alpha acid 4 -- 5 % / beta acid 4 -- 5 % )

 Tettnang -- Comes from Tettnang , a small town in southern Baden - Württemberg in Germany . The region produces significant quantities of hops , and ships them to breweries throughout the world . Noble German dual - use hop used in European pale lagers , sometimes with Hallertau . Soft bitterness . ( Alpha acid 3.5 -- 5.5 % / beta acid 3.5 -- 5.5 % )

 English noble varieties are Fuggle , East Kent Goldings and Goldings . They are characterized through analysis as having an alpha : beta ratio of 1 : 1 , low alpha - acid levels ( 2 -- 5 % ) with a low cohumulone content , low myrcene in the hop oil , high humulene in the oil , a ratio of humulene : caryophyllene above three , and poor storability resulting in them being more prone to oxidation . In reality , this means they have a relatively consistent bittering potential as they age , due to beta - acid oxidation , and a flavour that improves as they age during periods of poor storage .

 Other Uses ( edit )

 2 - methyl - 3 - buten - 2 - ol

 In addition to beer , hops are used in herbal teas and in soft drinks . These soft drinks include Julmust ( a carbonated beverage similar to soda that is popular in Sweden during December ) , Malta ( a Latin American soft drink ) and kvass . Hops can be eaten , the young shoots of the bine are edible and can be cooked similar to asparagus .

 Hops may be used in herbal medicine in a way similar to valerian , as a treatment for anxiety , restlessness , and insomnia . A pillow filled with hops is a popular folk remedy for sleeplessness , and animal research has shown a sedative effect . The relaxing effect of hops may be due , in part , to the specific degradation product from alpha acids , 2 - methyl - 3 - buten - 2 - ol , as demonstrated from nighttime consumption of non-alcoholic beer . 2 - methyl - 3 - buten - 2 - ol is structurally similar to tert - amyl alcohol which was historically used as an anesthetic . Hops tend to be unstable when exposed to light or air and lose their potency after a few months ' storage .

 Hops are of interest for hormone replacement therapy and are under basic research for potential relief of menstruation - related problems .

 In preliminary veterinary research , hops compounds are under study for potential activity against pasture - associated laminitis in horses .

 Toxicity ( edit )

 Dermatitis sometimes results from harvesting hops . Although few cases require medical treatment , an estimated 3 % of the workers suffer some type of skin lesions on the face , hands , and legs . Hops are toxic to dogs .

 See also ( edit )

 Beer portal

 Gruit , an old - fashioned herb mixture used for bittering and flavouring beer , popular before the extensive use of hops

 Mugwort , a herb historically used as a bitter in beer production

 Oast house , a building designed for drying hops

 Rhamnus prinoides , a plant whose leaves are used in the Ethiopian variety of mead called tej

 Humulus lupulus , the hop plant

 References ( edit )

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 Jump up ^ `` Beer Breakthrough : Hops May Prevent Pasture - Associated Laminitis '' . Horse Collaborative. 1 August 2014 . Archived from the original on 7 December 2014 . Retrieved 11 December 2014 .

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 External links ( edit )

 Wikimedia Commons has media related to Humulus lupulus .

 `` Hop '' . The New Student 's Reference Work . 1914 .

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