Lager (/ˈlɑːɡər/;German:[ˈlaːɡɐ]ⓘ) is astyle ofbeer brewed andconditioned at low temperature.[1] Lagers can bepale,amber, ordark. Pale lager is the most widely consumed and commercially available style of beer.[2] The term "lager" comes from the German word for "storage", as the beer was stored before drinking, traditionally in the same cool caves in which it was fermented.[3]
As well as maturation incold storage, most lagers are distinguished by the use ofSaccharomyces pastorianus, a "bottom-fermenting" yeast that ferments at relatively cold temperatures.
Until the 19th century, theGerman wordLagerbier (de) referred to all types ofbottom-fermented, cool-conditioned beer in normal strengths. InGermany today, it mainly refers to beers fromsouthern Germany,[4] either "Helles" (pale) or "Dunkles" (dark).Pilsner, a more heavilyhopped pale lager, is most often known as "Pilsner", "Pilsener", or "Pils". Other lagers areBock,Märzen, andSchwarzbier. In theUnited Kingdom, the term commonly refers to pale lagers derived from the Pilsner style.[5]
While cold storage of beer, "lagering", in caves for example, was a common practice throughout the medieval period, bottom-fermenting yeast seems to have emerged from a hybridization in the early fifteenth century.[6]
In 2011, a team of researchers claimed to have discovered thatSaccharomyces eubayanus is responsible for creating the hybrid yeast used to make lager.[7][8]
Based on the numbers of breweries, lager brewing became the main form of brewing in theKingdom of Bohemia between 1860 and 1870, as shown in the following table:[9]
Year
Total breweries
Lager breweries
Lager percentage
1860
416
135
32.5%
1865
540
459
85.0%
1870
849
831
97.9%
In the 19th century, before the advent of refrigeration, German brewers would dig cellars for lagering and fill them with ice from nearby lakes and rivers, which would cool the beer during the summer months. To further protect the cellars from the summer heat, they would plantchestnut trees, which have spreading, dense canopies but shallow roots which would not intrude on the caverns. The practice of serving beer at these sites evolved into the modernbeer garden.[10]
The rise of lager was entwined with the development ofrefrigeration, as it made it possible to brew lager year-round (brewing in the summer had previously been banned in many locations across Germany), and efficient refrigeration also made it possible to brew lager in more places and keep it cold until serving.[11] The first large-scale refrigerated lagering tanks were developed for Gabriel Sedelmayr'sSpaten Brewery in Munich byCarl von Linde in 1870.[11]
Lager uses a process ofcool fermentation, followed by maturation in cold storage. The German word "Lager" means storeroom or warehouse. The yeast generally used with lager brewing isSaccharomyces pastorianus. It is a close relative of theSaccharomyces cerevisiae yeast used for ales, which undergo warm fermentation at 18-24C.[citation needed]
While prohibited by the GermanReinheitsgebot tradition, lagers in some countries may include a proportion ofadjuncts, usually rice or maize. Adjuncts entered United States brewing as a means of thinning out the body of beers, balancing the large quantities of protein introduced bysix-row barley. Adjuncts are often used now in beermaking to introduce a large quantity of sugar, and thereby increaseABV, at a lower price than a formulation using an all-malt grain bill. There are, however, cases in which adjunct usage actually increases the cost of manufacture.[12]
It is possible to use lager yeast in awarm fermentation process, such as with Americansteam beer; while GermanAltbier andKölsch ales are brewed withSaccharomyces cerevisiae top-fermenting ale yeast, but matured as a lager in cold storage, and classified asobergäriges lagerbier (top-fermented lager beer).[13][14]
Lagers range in colour from extremely pale, through amber beers such as Vienna lager, to dark brown and black Dunkel and Schwarzbier. The depth of colour comes from the specific grain bill used in the beers; paler lagers use unroasted barley and may even add other grains such as rice or corn to lighten the color and provide a crisp, bright finish to the flavour. Darker lagers use roasted grains and malts to produce a more roasted, even slightly burnt, flavour profile.
The most common lagers in worldwide production arepale lagers. The flavour of these lighter lagers is usually mild, and the producers often recommend that the beers be served refrigerated.
Pale lager is a very pale togolden-coloured lager with a well attenuated body andnoble hop bitterness. The brewing process for this beer developed in the mid 19th century whenGabriel Sedlmayr tookpale ale brewing techniques back to theSpaten Brewery inGermany and applied it to existing lagering brewing methods.[16]
This approach was picked up by other breweries, most notablyPilsner Urquell Brewery inBohemia (now part of theCzech Republic) whereJosef Groll produced the firstPilsner beer. The resulting pale coloured, lean and stable beers were very successful and gradually spread around the globe to become the most common form of beer consumed in the world today.[17]
Amber lagers are generally darker in color than pale lagers, often a deep tan or amber color. Among the common styles of amber lager areMärzen, traditionally brewed in Munich for the celebration ofOktoberfest,Bock, a higher alcohol-content amber lager originating inEinbeck in central Germany, and the widely distributed Vienna lager.
The Vienna lager style was developed byAnton Dreher in the late 1830s. While on a trip to England and Scotland in 1833 with Gabriel Sedlmayr, Dreher gained knowledge of the pale malt making process. Dreher combined the pale malt making techniques with cold bottom fermentation, using yeast given to him by Sedlmayr. In late 1840, Anton Dreher started renting a cellar to mature his beer under cold conditions, a process that is called "lagering". The resulting beer was clean-tasting and relatively pale for the time thanks to the use of smoke-free "English" hot air kilns, resulting in a pale amber colour.[18]: 8–18
The beer style became well-known internationally, in particular due to the Dreher brewery's restaurant and beer hall at theInternational Exposition of 1867 in Paris, and started getting copied by many of the US-American lager breweries founded by German immigrants.[18]: 32–34 The first amber-colouredOktoberfest-Märzen brewed by Franziskaner-Leistbräu in 1872 was also a Vienna-style beer brewed to a higher strength.[18]: 61–62
The Vienna lager style has survived to this day, mostly thanks to the emerging microbrewing, home-brewing and craft beer scene in the United States of the 1980s and 1990s.[18]: 90 Due to the influence of the American craft beer movement, Vienna lager can again be found in Europe, including traditional Austrian breweries like Ottakringer and Schwechater who have made this pale amber beer style part of their range of beers again.[18]: 93
Pale lagers were not common until the later part of the 19th century when the use of lighter roasted malts spread.[20][better source needed] Dark lagers may be calledDunkel,tmavé orSchwarzbier depending on region, colour or brewing method.[citation needed]
Tmavé is Czech for "dark" – beers which are so dark as to be black are termedčerné pivo, "black beer".[21]Dunkel is German for "dark". At 4.5% to 6%abv, Dunkel is weaker thanDoppelbock, a stronger dark Bavarian beer. Dunkel was the original style of the Bavarian villages and countryside.[22]Schwarzbier, a much darker, almost black beer with a chocolate or licorice-like flavour, similar tostout, is brewed inSaxony andThuringia.[citation needed]
^Pasteur, Louis,Studies in Fermentation, 1879. English translation reprinted 2005 Beerbooks.comISBN0966208420 p. 10. CitingMoniteur de la Brasserie, 23 April 1871.