View source for Kvass

{{Short description|Fermented cereal-based non-alcoholic beverage}}
{{Redirect|Gira}}
{{Use dmy dates|date=May 2022}}
{{Infobox food
| name = Kvass
| image = Mint bread kvas.jpg
| image_size = 250px
| caption = A mug of mint kvass and its ingredients
| alternate_name = Kvas, quass, quasse, quas, quash, kuass, kwas, gira, burakhi, kali
| region = [[Baltic region|Northeastern Europe]]; [[Central and Eastern Europe]]; [[Caucasus]]; [[Xinjiang]], China; [[Heilongjiang]], China
| associated_cuisine = [[Slavs|Slavic]] ([[Belarusian cuisine|Belarusian]], [[Polish cuisine|Polish]],<ref name="kuch1"/> [[Russian cuisine|Russian]],<ref>{{cite web |url=https://jordanrussiacenter.org/event-recaps/kvas-patriotism-in-russia-cultural-problems-cultural-myths/ |title=Kvas Patriotism in Russia: Cultural Problems, Cultural Myths |language=en |access-date=2023-11-28 |publisher=NYU Jordan Center |archive-date=2 March 2022 |archive-url=https://web.archive.org/web/20220302020748/https://jordanrussiacenter.org/event-recaps/kvas-patriotism-in-russia-cultural-problems-cultural-myths/ |url-status=dead }}</ref><ref name="rbth_com">{{cite web |url=https://www.rbth.com/russian-kitchen/334126-brief-history-drink-kvass |title=A brief history of Kvass, Russia's 'bread in a bottle' |work=Russia Beyond |date=23 August 2021 |language=en |access-date=2023-11-28 |archive-date=30 November 2023 |archive-url=https://web.archive.org/web/20231130164552/https://www.rbth.com/russian-kitchen/334126-brief-history-drink-kvass |url-status=live |last1=Sinelschikova |first1=Yekaterina }}</ref><ref name="serg1">{{cite web |url=https://www.sergiev-kanon.ru/azbuka_zdorov_ya/istoriya_kvasa_i_ego_poleznye_svoystva.html |title=История кваса и его полезные свойства |language=ru |access-date=2023-11-28 |publisher=Сергиев Канон |archive-date=30 November 2023 |archive-url=https://web.archive.org/web/20231130164553/https://www.sergiev-kanon.ru/azbuka_zdorov_ya/istoriya_kvasa_i_ego_poleznye_svoystva.html |url-status=live }}</ref>  
and [[Ukrainian cuisine|Ukrainian]]),  [[Estonian cuisine|Estonian]], [[Latvian cuisine|Latvian]], [[Lithuanian cuisine|Lithuanian]], [[Georgian cuisine|Georgian]]<ref>{{Cite web |date=2024-07-31 |title=15 Traditional Georgian Drinks: Qvevri Wine, Mountain Tea & More |url=https://wander-lush.org/traditional-georgian-drinks/ |access-date=2025-03-06 |website=Wander Lush |language=en-US}}</ref> and [[Uyghur cuisine]]
| course = Beverage
| type = Fermented low-alcoholic beverage
| served = Cold or room temperature
| main_ingredient = [[Rye bread]] or [[rye flour]] and rye malt, as well as water and [[yeast]]
| minor_ingredient = [[Berry|Berries]], fruits, [[herbs]], [[honey]]
| variations = Beetroot kvass,<ref name="Fermented Food Products">{{Cite book |editor-last1=Amaresan |editor-first1=Natarajan |editor-last2=Ayyadurai |editor-first2=Sankaranarayanan |editor-last3=Dhanasekaran |editor-first3=Dharumadurai |title=Fermented Food Products |date=2020 |publisher=Taylor & Francis |isbn=978-0-367-22422-6 |pages=287–292}}</ref> white kvass<ref>{{cite web |last=Tarasevich |first=Grigory |title=White kvass: An old drink with a new taste |date=5 September 2013 |url=https://www.rbth.com/arts/2013/09/04/white_kvass_an_old_drink_with_a_new_taste_29499.html |website=[[Russia Beyond]] |access-date=30 July 2021 |archive-date=20 July 2021 |archive-url=https://web.archive.org/web/20210720030933/https://www.rbth.com/arts/2013/09/04/white_kvass_an_old_drink_with_a_new_taste_29499.html |url-status=live }}</ref>
| calories = 30–100
| calories_ref = &nbsp;(approximately)
| protein = <0.15<ref name="Foodbalt">{{cite journal |last1=Līdums |first1=Ivo |last2=Kārkliņa |first2=Daina |last3=Ķirse |first3=Asnate |last4=Šabovics |first4=Mārtiņš |date=April 2017 |title=Nutritional value, vitamins, sugars and aroma volatiles in naturally fermented and dry kvass |url=http://llufb.llu.lv/conference/foodbalt/2017/FoodBalt_2017_Conference_Proceedings.pdf#page=61 |journal=Foodbalt |publisher=[[Faculty of Food Technology, Latvia University of Life Sciences and Technologies]] |pages=61–65 |doi=10.22616/foodbalt.2017.027 |issn=2501-0190 |access-date=4 January 2022 |archive-date=4 January 2022 |archive-url=https://web.archive.org/web/20220104205221/https://llufb.llu.lv/conference/foodbalt/2017/FoodBalt_2017_Conference_Proceedings.pdf#page=61 |url-status=live }}</ref>
| fat = <0.10<ref name="Foodbalt"/>
| carbohydrate = 5.90<ref name="Foodbalt"/>
}}

'''Kvass'''<!--for names in other languages see entire [[Kvass#Terminology]] section below--> is a [[fermented]], cereal-based, low-alcoholic beverage of cloudy appearance and a sweet and sour taste.

Kvass originates from northeastern Europe, where grain production was considered insufficient for beer to become a daily drink. The first written mention of kvass is found in ''[[Primary Chronicle]]'', describing the celebration of [[Vladimir the Great]]'s<ref>{{cite web |url=https://www.danceshistoricalmiscellany.com/vladimir-great-pagan-philanderer-saint/ |title=Vladimir the Great: From Pagan Philanderer to Christian Saint |date=8 April 2014 |language=en |access-date=2023-11-28 |publisher=Dance's Historical Miscellany |archive-date=30 November 2023 |archive-url=https://web.archive.org/web/20231130164554/https://www.danceshistoricalmiscellany.com/vladimir-great-pagan-philanderer-saint/ |url-status=live }}</ref><ref>{{cite web |url=https://christianhistoryinstitute.org/magazine/article/vladimir-adopts-christianity |title=Vladimir Adopts Christianity |language=en |access-date=2023-11-28 |publisher=Christian History Institute |archive-date=5 December 2023 |archive-url=https://web.archive.org/web/20231205191835/https://christianhistoryinstitute.org/magazine/article/vladimir-adopts-christianity |url-status=live }}</ref> baptism in 988.<ref>{{cite web |url=https://rskrf.ru/tips/eksperty-obyasnyayut/pavel-syutkin-kvas-bez-prikras-pravda-i-mify-o-traditsionnom-russkom-napitke/ |title=Павел Сюткин: Квас без прикрас – правда и мифы о традиционном русском напитке |language=ru |access-date=2023-11-28 |publisher=Российский Союз Потребителей (Росконтроль) |archive-date=30 November 2023 |archive-url=https://web.archive.org/web/20231130164554/https://rskrf.ru/tips/eksperty-obyasnyayut/pavel-syutkin-kvas-bez-prikras-pravda-i-mify-o-traditsionnom-russkom-napitke/ |url-status=live }}</ref> 

Traditionally, kvass is made from a mash of [[rye]] bread or rye flour and malt soaked in hot water, fermented for about 12 hours with the help of sugar and [[bread yeast]] or [[baker's yeast]] at room temperature. In industrial methods, kvass is produced from [[wort]] concentrate combined with various grain mixtures. It is a drink known in Belarus, Estonia, Latvia, Lithuania, Moldova, [[Armenia]], Georgia, Poland,<ref name="kuch1">{{cite web |url=https://kuchnia.wp.pl/co-warto-wiedziec-o-kwasie-chlebowym-6054630961177729g/2 |title=Co warto wiedzieć o kwasie chlebowym |date=8 January 2016 |language=pl |access-date=2023-11-28 |publisher=WP Kuchnia |archive-date=22 October 2023 |archive-url=https://web.archive.org/web/20231022043155/https://kuchnia.wp.pl/co-warto-wiedziec-o-kwasie-chlebowym-6054630961177729g/2 |url-status=live |last1=s. a. |first1=Wirtualna Polska Media }}</ref><ref>{{cite web |url=https://zywienie.medonet.pl/produkty-spozywcze/napoje/kwas-chlebowy-i-jego-znaczenie-dla-zdrowia-przepis-na-kwas-chlebowy/9qs84h4 |title=Kwas chlebowy i jego znaczenie dla zdrowia. Przepis na kwas chlebowy |date=19 December 2022 |language=pl |access-date=2023-11-28 |publisher=Medonet |archive-date=30 November 2023 |archive-url=https://web.archive.org/web/20231130164553/https://zywienie.medonet.pl/produkty-spozywcze/napoje/kwas-chlebowy-i-jego-znaczenie-dla-zdrowia-przepis-na-kwas-chlebowy/9qs84h4 |url-status=live }}</ref> Russia,<ref name="serg1"/><ref name="rbth_com" /> and Ukraine. Kvass (or beverages similar to it) are also popular in some parts of China, Finland, Kazakhstan, and Uzbekistan.

==Terminology==
The word ''kvass'' is ultimately from [[Proto-Indo-European language|Proto-Indo-European]] base [[wikt:Reconstruction:Proto-Indo-European/kwh₂et-|*''kwh₂et-'']] ('to become sour').<ref>{{cite web|url=http://www.palaeolexicon.com/Word/Show/19826|title=Palaeolexicon – The Proto-Indo-European word *kwat-|website=palaeolexicon.com|access-date=17 October 2018|archive-date=16 January 2018|archive-url=https://web.archive.org/web/20180116081425/http://www.palaeolexicon.com/Word/Show/19826|url-status=live}}</ref> In English it was first mentioned in a text around 1553 as ''quass''.<ref>{{cite encyclopedia |encyclopedia = [[Webster's Dictionary]] |title = kvass |publisher = [[Merriam-Webster]] |url = https://www.merriam-webster.com/dictionary/kvass |access-date = 2023-06-10 |archive-date = 2 January 2023 |archive-url = https://web.archive.org/web/20230102034902/https://www.merriam-webster.com/dictionary/kvass |url-status = live }}</ref><ref>Kvass in Oxford English Dictionary. ''c 1553 Chancelour Bk. Emp. Russia in Hakluyt Voy. (1886) III. 51 Their drinke is like our peny Ale, and is called Quass.''</ref> Nowadays, the name of the drink is almost the same in most languages: in [[Polish language|Polish]]: ''{{lang|pl|kwas chlebowy}}'' ({{literal translation|bread kvass}}, to differentiate it from {{Lang|pl|kwas}}, 'acid', originally from {{Lang|pl|kwaśny}}, 'sour');  [[Belarusian language|Belarusian]]: {{lang|be|квас}}, ''{{transliteration|be|kvas}}''; [[Russian language|Russian]]: {{lang|ru|квас}}, ''{{transliteration|ru|kvas}}''; [[Ukrainian language|Ukrainian]]: {{lang|uk|квас/хлібний квас/сирівець}}, {{transliteration|uk|''kvas''/''khlibny kvas''/''syrivets''}}; [[Latvian language|Latvian]]: ''{{lang|lv|kvass}}''; [[Romanian language|Romanian]]: ''{{lang|ro|cvas}}''; [[Hungarian language|Hungarian]]: ''{{lang|hu|kvasz}}''; [[Serbian language|Serbian]]: ''{{lang|sr|квас/kvas}}''; [[Mandarin Chinese]]: {{lang|zh|格瓦斯/克瓦斯}}, {{transliteration|zh|''géwǎsī''/''kèwǎsī''}}; [[Eastern Finnish dialects|Eastern Finnish]]: ''{{lang|fi|vaasa}}''. Non-[[cognate]]s include [[Estonian language|Estonian]] ''{{lang|et|kali}}'', [[Finnish language|Finnish]] ''{{lang|fi|kalja}}'', [[Georgian language|Georgian]] {{lang|ka|ბურახი}}, ''{{transliteration|ru|burakhi}}''; [[Latvian language|Latvian]] ''{{lang|lv|dzersis}}'' ({{literal translation|beverage}}), [[Latgalian language|Latgalian]] {{Lang|ltg|dzyra}} ({{literal translation|beverage}}, similar to Lithuanian {{Lang|lt|gira}}), [[Lithuanian language|Lithuanian]] ''{{lang|lt|gira}}'' ({{literal translation|beverage}}, similar to Latvian ''{{lang|lv|dzira}}''), and [[Swedish language|Swedish]] ''{{lang|sv|bröddricka}}'' ({{literal translation|bread drink}}).

==Production==
[[File:Kvas on fridge.jpg|thumb|left|Home fermentation of kvass in glass jars]]

In the traditional method, either dried rye bread or a combination of [[rye flour]] and rye [[malt]] is used. The dried rye bread is extracted with hot water and incubated for 12 hours at room temperature, after which [[bread yeast]] and sugar are added to the extract and fermented for 12 hours at {{convert|20|C|K F}}. Alternatively, rye flour is boiled, mixed with rye malt, sugar, and [[baker's yeast]] and then fermented for 12 hours at {{convert|20|C|K F}}.<ref name="Fermented Food Products"/>

The simplest industrial method produces kvass from a [[wort]] concentrate. The concentrate is warmed up and mixed with a water and sugar solution to create wort with a sugar concentration of 5–7% and [[pasteurization|pasteurized]] to stabilize it. After that, the wort is pumped into a fermentation tank, where [[baker's yeast]] and [[lactic acid bacteria]] culture is added, and the solution is fermented for 12–24 hours at {{convert|12|to|30|C|K F}}. Only around 1% of the extract is fermented out into [[ethanol]], [[carbon dioxide]], and [[lactic acid]]. Afterwards, the kvass is cooled to {{convert|6|C|K F}}, clarified through either filtration or [[centrifugation]], and adjusted for sugar content, if necessary.<ref name="Hornsey">{{Cite book |last=Hornsey |first=Ian Spencer |date=2012 |title=Alcohol and its Role in the Evolution of Human Society |publisher=[[Royal Society of Chemistry]] |isbn=978-1-84973-161-4 |pages=296–300}}</ref>

Initially, it was filled in large containers from which the kvass was sold on streets, but now, the vast majority of industrially produced kvass is filled and sold in 1–3-litre plastic bottles and has a [[shelf life]] of 4–6 weeks.<ref>{{Cite book |editor-last1=Gobbetti |editor-first1=Marco |editor-last2=Gänzle |editor-first2=Michael |date=2013 |title=Handbook on Sourdough Biotechnology |publisher=[[Springer Publishing]] |isbn=978-1-4614-5424-3 |pages=272–274}}</ref>

Kvass is usually 0.5–1.0% alcohol by weight,<ref name="Hornsey 2003 p. 8">{{cite book |last=Hornsey |first=I.S. |title=A History of Beer and Brewing |publisher=Royal Society of Chemistry |series=RSC paperbacks |year=2003 |isbn=978-0-85404-630-0 |url=https://books.google.com/books?id=QqnvNsgas20C&pg=PA8 |access-date=21 March 2022 |page=8 |quote=A similar, low alcohol (0.5–1.0%) drink, kvass… may be a 'fossil beer'}}</ref><ref>{{Cite journal |last1=Dlusskaya |first1=Elena |last2=Jänsch |first2=André |last3=Schwab |first3=Clarissa |last4=Gänzle |first4=Michael G. |date=2008-05-01 |title=Microbial and chemical analysis of a kvass fermentation |url=https://doi.org/10.1007/s00217-007-0719-4 |journal=European Food Research and Technology |language=en |volume=227 |issue=1 |pages=261–266 |doi=10.1007/s00217-007-0719-4 |s2cid=84724879 |issn=1438-2385 |quote=The predominant carbohydrates are maltose, maltotriose, glucose, and fructose, the ethanol content is 1% or less [2]. Kvass is considered to be spoiled if ethanol accumulates to higher levels.|url-access=subscription }}</ref> but may sometimes be as high as 2.0%.<ref name="gazolsz" />

==History==
[[File:Шенберг Христиан Квасник По рисунку Христиана Гейслера 1791 - 1792 годы Эрмитаж.jpg|thumb|180px|A kvass vendor (kvasnik) in [[Russian Empire]] in the 18th century]]

The exact origins of kvass are unclear, and whether it was invented by [[Slavic people]] or any other Eastern European ethnicity is unknown,<ref name="Garshol">{{Cite book |last=Garshol |first=Lars Marius |date=2020 |title=Historical Brewing Techniques: The Lost Art of Farmhouse Brewing |url=https://books.google.com/books?id=_KDgDwAAQBAJ&pg=PA254 |publisher=[[Brewers Publications]] |isbn=978-1-938-46955-8 |pages=254–257 |quote=Nobody knows who invented kvass, or when. The first written mention of it is in Nestor’s ''Primary Chronicle'', compiled in Kiev in the early twelfth century. At that time there was no Russia as we understand it today, and whether it was a Slavic people or some other eastern European ethnicity that invented kvass will probably never be known.}}</ref> although some Polish sources claim that kvass was invented by Slavs.<ref name="ministerstwo" /><ref name="gazolsz" /> Kvass has existed in the northeastern part of Europe, where grain production is thought to have been insufficient for beer to become a daily drink.<ref name="Garshol"/> It has been known among the [[Early Slavs]] since the 10th century.<ref name="ministerstwo" /><ref name="gazolsz" /> Possibly invented in the [[Kievan Rus']] and known there since at least the 10th century, kvass has become one of the symbols of East Slavic cuisine.<ref name="gazolsz" /> The first written mention of kvass is found in the ''[[Primary Chronicle]]'', describing the celebration of [[Vladimir the Great]]'s baptism in 988, when kvass along with [[mead]] and food was given out to the citizens of [[Kiev]].<ref>{{cite web |url=https://assets.press.princeton.edu/chapters/s5285.pdf |title=The Early History of Kiev |language=en |access-date=2023-11-28 |publisher=Princeton University |archive-date=19 November 2023 |archive-url=https://web.archive.org/web/20231119193746/http://assets.press.princeton.edu/chapters/s5285.pdf |url-status=live }}</ref> Kvass-making remained a daily household activity well into the 19th century.<ref name="Hornsey"/>

In the second half of the 19th century, with military engagement, increasing industrialization, and large-scale projects, such as the construction of the [[Trans-Siberian Railway]] creating a growing need to supply large numbers of people with foodstuff for extended periods of time, kvass became commercialized; more than 150 kvass varieties, such as apple, pear, mint, lemon, chicory, raspberry, and cherry were recorded. As commercial kvass producers began selling it in barrels on the streets, domestic kvass-making started to decline.<ref name="Hornsey"/> For example, in the year ended 30 June 1912, there were 17 factories in the [[Governorate of Livonia]], producing a total of 437,255 gallons of kvass.<ref>{{Cite book |date=1913 |title=Daily Consular and Trade Reports |url=https://books.google.com/books?id=-mU3AQAAMAAJ&pg=PA114 |publisher=[[Government Printing Office]] |location=Washington |volume=1 |page=114}}</ref>

In the 1890s, the first scientific studies into the production of kvass were conducted in Kiev, and in the 1960s, commercial mass production technology of kvass was further developed by chemists in Moscow.<ref name="Hornsey"/>

== By country ==
===Belarus===
[[File:Kvass in Grodno, Belarus.png|thumb|Kvass trailer in [[Grodno]], Belarus (2019)]]

Belarus has several breweries producing kvass: [[Alivaria Brewery]], {{Interlanguage link|Babrujski Brovar|be|Бабруйскі бровар|be-tarask|Бабруйскі бровар}}, and {{Interlanguage link|Krinitsa (company)|lt=Krinitsa|be|Крыніца (бровар)|be-tarask|Крыніца (бровар)}}. It also has a variety of kvass tasting and entertainment festivals.<ref name="wab">{{cite book |last1=Webb |first1=Tim |last2=Beaumont |first2=Stephen |title=World Atlas of Beer: THE ESSENTIAL NEW GUIDE TO THE BEERS OF THE WORLD |date=2016 |publisher=Hachette UK |page=148 |isbn=9781784722524 |url=https://books.google.com/books?id=h_OpCwAAQBAJ&pg=PA148}}</ref> The largest show takes place in the city of [[Lida]].<ref name="dib">{{cite web |title=Drinks in Belarus |url=https://www.belarus.by/en/about-belarus/cuisine/drinks |website=belarus.by |access-date=14 July 2020 |archive-date=3 August 2020 |archive-url=https://web.archive.org/web/20200803003349/https://www.belarus.by/en/about-belarus/cuisine/drinks |url-status=dead }}</ref>

<gallery widths=300px>
File:2022-09-17 Белы квас Аліварыя.jpg|Belarusian [[white kvass]], produced by [[Alivaria Brewery]] (Minsk, 2022)
</gallery>

===Estonia===
[[File:Nõukogude-aegne kaljavaat Nõukogude aja näitusel Tallinnas Rotermanni kvartalis, 14. august 2011.jpg|thumb|A street [[kvass barrel]] used by a vendor]]
 
In Estonia, kvass is known as {{Lang|et|kali}}. Initially, it was made from either [[brewer's spent grain]] or [[wort]] left to ferment in a closed container, but later, special kvass bread ({{Lang|et|kaljaleib}}) or industrially produced malt concentrate started to be used. Nowadays, ''{{Lang|et|kali}}'' generally is industrially produced with the use of [[pasteurization]], the addition of [[preservatives]], and artificial [[carbonation]].<ref>{{Cite book |last1=Sõukand |first1=Renata |last2=Kalle |first2=Raivo |date=2016 |title=Changes in the Use of Wild Food Plants in Estonia 18th – 21st Century |url=https://books.google.com/books?id=FOF0DQAAQBAJ&pg=PA98 |publisher=[[Springer Publishing]] |isbn=978-3-319-33949-8 |page=98}}</ref>

===Finland===
In Finland, a fermented drink made from a mixture of rye flour and rye malt was ubiquitous in parts of [[Eastern Finland]] and was heated in the oven. It was called {{Lang|fi|kalja}} (which can also be used to refer to [[small beer]]) or {{Lang|fi|vaasa}} (in [[Eastern Finnish dialects|Eastern Finnish]]), while nowadays the drink is often known as {{Lang|fi|kotikalja}} ({{literal translation|home kalja}}) and is available in many work canteens, gas stations, and lower-end restaurants.<ref name="Garshol"/>

Traditionally, {{Lang|fi|kalja}} was usually made in households once a week from a mixture of malted and unmalted rye grains. Other grains, such as oats or barley, were also sometimes used; occasionally, leftover potatoes or pieces of bread were added. Everything was mixed with water in a metal cauldron or a clay pot and kept warm in the oven or by the stove for at least six hours for the mixture to darken and sweeten. Sometimes, the grain solids were filtered out through [[lautering]]. In Eastern Finland, the mixture was formed into large loaves and briefly baked for the crust to turn brown. The porridge or pieces of the malt bread were mixed into a wooden cask with water and fermented for one or two days with a previous batch, a sourdough starter, [[spontaneous fermentation|spontaneously]] or in more recent times with commercial baker's yeast. In the early 20th century, with sugar becoming more readily available, it started replacing the [[malting]] process, and modern ''{{Lang|fi|kalja}}'' is made from dark rye malt, sugar, and baker's yeast.<ref>{{Cite book |last1=Laitinen |first1=Mika |last2=Mosher |first2=Randy |date=2019 |title=Viking Age Brew: The Craft of Brewing Sahti Farmhouse Ale |publisher=[[Chicago Review Press]] |isbn=978-1-641-60047-7 |pages=98–104}}</ref>

===Latvia===
[[File:Un marchand de kwass, en Livonie. — Dessin de d'Henriet.jpg|thumb|A 19th century [[engraving]] by Dessin de d'Henriet depicting kvass vendors in [[Governorate of Livonia|Livonia]]]]
[[File:kvass-Jul77.png|thumb|A kvass street vendor in [[Riga|Rīga]] (1977)]]

In [[Latvian language|Latvian]], kvass was also called {{Lang|lv|dzersis}}.<ref>{{cite web |title=What and How Latvians Used to Eat. Acorn Coffee, Beer, Sugar and Sweets. |date=11 March 2021 |url=https://latvianeats.com/what-and-how-latvians-used-to-eat-acorn-coffee-beer-sugar-and-sweets/ |website=Latvia Eats |access-date=30 July 2021 |archive-date=27 July 2021 |archive-url=https://web.archive.org/web/20210727235812/https://latvianeats.com/what-and-how-latvians-used-to-eat-acorn-coffee-beer-sugar-and-sweets/ |url-status=live }}</ref> After the [[dissolution of the Soviet Union]] in 1991, the street vendors disappeared from the streets of Latvia due to new health laws that banned its sale on the street. Economic disruptions forced many kvass factories to close. The Coca-Cola Company moved in and began quickly dominating the soft drink market. In 1998, the local soft drink industry adapted by selling bottled kvass and launching aggressive marketing campaigns. This surge in sales was stimulated by the fact that kvass sold for about half the price of Coca-Cola. In just three years, kvass constituted as much as 30% of the soft drink market in Latvia, while the market share of Coca-Cola fell from 65% to 44%. The Coca-Cola Company had losses in Latvia of about $1&nbsp;million in 1999 and 2000. Coca-Cola responded by purchasing kvass manufacturers and producing kvass at their own soft drink plants.<ref>{{cite news |last=Lyons |first=J. Michael |date=31 March 2002 |title=Soviet Brew Is Back, This Time, in Bottles |url=https://www.washingtonpost.com/archive/politics/2002/03/31/soviet-brew-is-back-this-time-in-bottles/066718dc-feb1-4382-85fa-c3eb36d2bcb3/ |newspaper=[[The Washington Post]] |access-date=14 July 2020}}</ref><ref>{{cite news |last=Smith |first=Benjamin |date=7 September 2002 |title=In Latvia, Forces of Globalism Ferment Market for Traditional Soft-Drink Brew |url=https://www.wsj.com/articles/SB968266405767974068 |newspaper=[[The Wall Street Journal]] |access-date=14 July 2020 |archive-date=4 December 2020 |archive-url=https://web.archive.org/web/20201204125730/https://www.wsj.com/articles/SB968266405767974068 |url-status=live }}</ref>

On 30 September 2010, the [[Saeima]] (parliament) adopted quality and classification requirements for kvass, defining it as "a beverage obtained by fermenting a mixture of kvass wort with a yeast of microorganism cultures to which sugar and other food sources and food additives are added or not added after the fermentation" with a maximum ABV of 1.2 percent, and differentiating it from an unfermented non-alcoholic mixture of grain product extract, water, flavourings, preservatives, and other ingredients, which is designated as a "kvass (malt) beverage".<ref>{{Cite web |url=https://likumi.lv/ta/en/en/id/218950-quality-and-classification-requirements-for-kvass-and-kvass-malt-beverage |title=Quality and Classification Requirements for Kvass and Kvass (Malt) Beverage |website=[[likumi.lv]] |access-date=30 July 2021 |archive-date=29 December 2021 |archive-url=https://web.archive.org/web/20211229231131/https://likumi.lv/ta/en/en/id/218950-quality-and-classification-requirements-for-kvass-and-kvass-malt-beverage |url-status=live }}</ref>

In 2014, Latvian kvass producers won seven medals at the Russian Beverage exposition in Moscow, with [[Ilgezeem]]'s ''Porter Tanheiser'' kvass winning two gold medals.<ref>{{Cite web |title=Latvian kvass takes awards at Moscow beverage expo |date=1 September 2014 |url=https://eng.lsm.lv/article/economy/economy/latvian-kvass-takes-awards-at-moscow-beverage-expo.a96725/ |publisher=[[Public Broadcasting of Latvia]] |accessdate=19 December 2021 |archive-date=21 December 2021 |archive-url=https://web.archive.org/web/20211221121643/https://eng.lsm.lv/article/economy/economy/latvian-kvass-takes-awards-at-moscow-beverage-expo.a96725/ |url-status=live }}</ref> In 2019, ''Iļģuciema kvass'' ranked second in the Most Loved Latvian Beverage Brand Top,<ref>{{cite web |title=Iļģuciema kvass won the 2nd place in The Latvia's Most Loved Drink top |date=9 October 2019 |url=https://ilgezeem.lv/en/ilguciema-kvass-won-the-2nd-place-in-the-latvias-most-loved-drink-top/ |publisher=[[Ilgezeem]] |accessdate=30 July 2021 |archive-date=19 June 2021 |archive-url=https://web.archive.org/web/20210619034801/https://ilgezeem.lv/en/ilguciema-kvass-won-the-2nd-place-in-the-latvias-most-loved-drink-top/ |url-status=live }}</ref>{{Unreliable source?|date=May 2022}} and first in the subsequent 2020 top.<ref>{{cite web |title=Iļģuciema kvass won 1st place in the Most Loved Latvian Beverage Brand top! |date=21 October 2020 |url=https://ilgezeem.lv/en/ilguciema-kvass-won-1st-place-in-the-most-loved-latvian-beverage-brand-top/ |publisher=[[Ilgezeem]] |accessdate=30 July 2021 |archive-date=24 September 2021 |archive-url=https://web.archive.org/web/20210924154636/https://ilgezeem.lv/en/ilguciema-kvass-won-1st-place-in-the-most-loved-latvian-beverage-brand-top/ |url-status=live }}</ref>{{Unreliable source?|date=May 2022}}

===Lithuania===
[[File:Vilnius (12663377025).jpg|thumb|A Lithuanian kvass barrel]]
In Lithuania, kvass is known as {{Lang|lt|gira}} and is widely available in bottles and drafts. The first written records of kvass and kvass recipes in [[Lithuania]] appeared in the 16th century.<ref>{{Cite journal |last=Laužikas |first=Rimvydas |date=2022 |title='À la Lituanienne': In Search of a Lithuanian Gastronomic Identity |url=https://www.lituanistika.lt/content/100191 |journal=Acta Litteraria Comparativa |language=en |volume=9 |pages=13–38 |issn=1822-5608 |archive-url=https://web.archive.org/web/20240910015738/https://www.lituanistika.lt/content/100191 |archive-date=10 September 2024 |via=Lituanistika Database |access-date=2 February 2025 |url-status=live }}</ref> Many restaurants in Lithuania make their own kvass, which they sell on the premises. Some brands of mass-produced Lithuanian kvass are also sold on the Polish market.<ref name="gerima" /> Strictly speaking, ''gira'' can be made from anything fermentable—such as [[caraway]] tea, [[beetroot]] juice, or berries—but it is made mainly from black bread, or barley or rye malt. 

===Poland===
[[File:Kwas chlebowy (EKO-NATURA).jpg|thumb|Varieties of natural {{Lang|pl|kwas chlebowy}}]]
[[File:Ogolnopolski Festiwal Dobrego Smaku 2018 (Poznan) (kwas chlebowy).jpg|thumb|Kvass tap at a festival in [[Poznań]]]]
[[File:Kwas chlebowy, kefir, kołacz i korowaj w polskim domu.jpg|thumb|Polish kvass served alongside [[kefir]], [[kolach (bread)|kolach]] and [[korovai]]]]

Kvass may have appeared in Poland as early as the 10th century,<ref name="ministerstwo">{{cite web|date=2018-06-03|title=Kwas chlebowy|first=Sławomir|last=Mucha|url=https://www.gov.pl/web/rolnictwo/kwas-chlebowy|publisher=[[Ministry of Agriculture and Rural Development (Poland)|Ministry of Agriculture and Rural Development of Poland]]|access-date=2022-05-26|archive-date=6 January 2022|archive-url=https://web.archive.org/web/20220106154352/https://www.gov.pl/web/rolnictwo/kwas-chlebowy|url-status=live}}</ref> it quickly became a popular beverage thanks to its easy and cheap method of production as well as its thirst-quenching and digestion-aiding qualities.<ref>{{cite book|last=Wieczorek|first=K.|date=2006|title=Młyn na Stawkach. Nad Czarną|location=Lubiaszów}}</ref> By the time of [[Jogaila]]'s rule, kvass was universal.<ref name="gazolsz">{{cite web|url=https://gazetaolsztynska.pl/775533,Kwas-chlebowy-Zapomniany-skarb-polskiej-kuchni.html|title=Kwas chlebowy. Zapomniany skarb polskiej kuchni|last=Snopkow|first=Paweł|date=2021-10-23|website=gazetaolsztynska.pl|publisher=[[Gazeta Olsztyńska]]|access-date=2022-05-26|archive-date=8 December 2021|archive-url=https://web.archive.org/web/20211208222140/https://gazetaolsztynska.pl/775533,Kwas-chlebowy-Zapomniany-skarb-polskiej-kuchni.html|url-status=live}}</ref> It was at first commonly drunk by peasants in the eastern parts of the country, but eventually the drink spread to the [[szlachta]].<ref name="gazolsz" /> One example of this is {{Lang|pl|kwas chlebowy sapieżyński kodeński}}, an old type of Polish kvass that is still sold as a contemporary brand. Its origins can be traced back to the 1500s, when {{Interlanguage link|Iwan Semenowicz Sapieha|lt=Jan Sapieha|pl|Iwan Semenowicz Sapieha}} founded the town of [[Kodeń]] on land granted by the [[Monarchs of Poland|Polish king]]. He then bought the mills and 24 villages of the surrounding areas from their previous landowners. Then, the taste of kvass became known among the Polish [[szlachta]], who used it for its supposed healing qualities. Throughout the 19th century, kvass remained popular among [[Polish people|Poles]] who lived in the [[Congress Poland]] of [[Imperial Russia]] and in [[Austrian Poland|Austrian Galicia]], especially the inhabitants of rural areas.<ref name="kchsk">{{cite web |date=2 July 2018 |title=Kwas chlebowy sapieżyński kodeński |url=https://www.gov.pl/web/rolnictwo/kwas-chlebowy-sapiezynski-kodenski |publisher=[[Ministry of Agriculture and Rural Development (Poland)|Ministry of Agriculture and Rural Development of Poland]] |access-date=30 July 2021 |archive-date=9 February 2022 |archive-url=https://web.archive.org/web/20220209114722/https://www.gov.pl/web/rolnictwo/kwas-chlebowy-sapiezynski-kodenski |url-status=live }}</ref> Up until the 19th century, recipes for local variants of kvass remained well-guarded secrets of families, [[religious order]]s, and monasteries.<ref>{{cite journal|last1=Dekowski|first1=J.P.|date=1968|title=Z badań nad pożywieniem ludu łowickiego (1880-1939)|journal=Seria Etnograficzna|issue=12|location=Łódź}}</ref>

The beverage production in Poland on an industrial scale can be traced back to the more recent interwar period, when the Polish state regained independence as the [[Second Polish Republic]]. In interwar Poland, kvass was brewed and sold in mass numbers by magnates of the Polish drinks market like the [[Warsaw|Varsovian]] brewery [[Haberbusch i Schiele]] or the ''Karpiński'' company.<ref>{{cite journal |last=Delorme |first=Andrzej |date=1–15 October 1999 |title=Alternatywa dla Coca Coli? |url=http://zb.eco.pl/zb/140/zdrowie.htm |journal=Pismo Ekologów |publisher=Zielone Brygady |number=14(140)/99 |issn=1231-2126 |access-date=21 February 2014 |archive-date=9 September 2012 |archive-url=https://web.archive.org/web/20120909013816/http://zb.eco.pl/zb/140/zdrowie.htm |url-status=live }}</ref> Kvass remained particularly popular in eastern Poland.<ref name="kchsk" /> However, with the collapse of many prewar businesses and much of the Polish industry during [[World War II]], kvass lost popularity following the aftermath of the war. It also gradually lost favour throughout the 20th century upon introducing mass-produced soft drinks and carbonated water into the Polish market.<ref>{{cite web|url=https://www.kwaschlebowy.eu/produkt/kwas-chlebowy-tradycyjny/|title=Historia kwasu chlebowego|website=kwaschlebowy.eu|publisher=Eko-Natura|access-date=2022-05-26|quote=W wieku XX kwas został zapomniany, wyparty przez wody gazowane i inne słodkie napoje.|archive-date=17 May 2022|archive-url=https://web.archive.org/web/20220517014316/https://www.kwaschlebowy.eu/produkt/kwas-chlebowy-tradycyjny/|url-status=live}}</ref><ref name="ministerstwo" /><ref name="gazolsz" /> In the early 21st century, kvass experienced a renaissance in Poland due to the heightened interest in healthy diets, natural products, and traditions.<ref name="ministerstwo" />

Kvass can be found in some supermarkets and grocery stores, where it is known in [[Polish language|Polish]] as {{Lang|pl|kwas chlebowy}} ({{IPA|pl|kvas xlɛbɔvɨ|}}). Commercial bottled versions of the drink are the most common variant, as some companies specialise in manufacturing a more modern version of the drink (some variants are manufactured in Poland whilst others are imported from its neighbouring countries, Lithuania and Ukraine being the most popular source).<ref name="gerima">[http://gerima.pl/index.html Gerima dystrybutor kwasu chlebowego w Polsce] {{Webarchive|url=https://web.archive.org/web/20131016154516/http://gerima.pl/index.html |date=16 October 2013 }} Gerima – distributor of kvass in Poland. {{in lang|pl}}</ref><ref name="ukrainski">{{cite web|title=Kwas chlebowy z Ukrainy – dlaczego warto go kupić?|url=http://www.zdrowozmiksowani.pl/kwas-chlebowy-z-ukrainy-dlaczego-warto-go-kupic/|publisher=Zdrowo Zmiksowani|website=zdrowozmiksowani.pl|date=22 October 2020|access-date=2022-05-26|archive-date=12 August 2022|archive-url=https://web.archive.org/web/20220812155338/http://www.zdrowozmiksowani.pl/kwas-chlebowy-z-ukrainy-dlaczego-warto-go-kupic/|url-status=dead}}</ref> However, old recipes for a traditional version of kvass exist. Some of them originate from eastern Poland;<ref>{{cite web |title = Kwas chlebowy sapieżyński kodeński |trans-title = Sapieżyński Kodeński kvass |language=pl |publisher = [[Lublin Voivodeship]] |website = lubelskie.pl |url = http://www.lubelskie.pl/?pid=647 |archive-url = https://web.archive.org/web/20131016163658/http://www.lubelskie.pl/?pid=647 |archive-date = 2013-10-16}}</ref> others from more central regions include adding honey for flavour.<ref>{{cite web|date=2019-01-25|title=Kwas chlebowy na miodzie z Grębkowa|first=Sławomir|last=Mucha|url=https://www.gov.pl/web/rolnictwo/kwas-chlebowy-na-miodzie-z-grebkowa|publisher=[[Ministry of Agriculture and Rural Development (Poland)|Ministry of Agriculture and Rural Development of Poland]]|access-date=2022-05-26|archive-date=26 May 2022|archive-url=https://web.archive.org/web/20220526225154/https://www.gov.pl/web/rolnictwo/kwas-chlebowy-na-miodzie-z-grebkowa|url-status=live}}</ref> Although commercial kvass is much easier to find in Polish shops, Polish manufacturers of more natural and healthier variants of kvass have become increasingly popular both within and outside of the country's borders.<ref>{{cite news |last = Jeziorska |first = Jolanta |date = 2009-09-08 |title = Ich kwas chlebowy podbija rynek |trans-title = Their kvass conquers the market |language = pl |work = [[Dziennik Łódzki]] |url = https://dzienniklodzki.pl/ich-kwas-chlebowy-podbija-rynek/ar/160252?cookie=1 |access-date = 2023-06-10 |archive-date = 2 January 2023 |archive-url = https://web.archive.org/web/20230102034905/https://dzienniklodzki.pl/ich-kwas-chlebowy-podbija-rynek/ar/160252?cookie=1 |url-status = live }}</ref><ref name="ministerstwo" /> A less healthy alternative of quick-to-make variants using kvass concentrate can also be purchased in shops.<ref>{{cite encyclopedia |title=S. Orgelbranda Encyklopedja Powszechna|year=1901|publisher=Wydawnictwo Towarzystwa Akcyjnego Odlewni Czcionek i Drukarni S. Orgelbranda Synów|location=Warszawa}}</ref> One colloquial Polish name for {{Lang|pl|kwas chlebowy}} is {{Lang|pl|wiejska oranżada}} ('rural orangeade').<ref name="gazolsz" /> In some Polish villages, such as [[Zaława]] and its surroundings, kvass was traditionally produced on every farm.<ref name="zaława">{{cite web|date=2020-04-10|title=Kwas chlebowy z Załawy|url=https://www.gov.pl/web/rolnictwo/kwas-chlebowy-z-zalawy|publisher=[[Ministry of Agriculture and Rural Development (Poland)|Ministry of Agriculture and Rural Development of Poland]]|access-date=2022-05-26|archive-date=19 March 2022|archive-url=https://web.archive.org/web/20220319194515/https://www.gov.pl/web/rolnictwo/kwas-chlebowy-z-zalawy|url-status=live}}</ref>

===Russia===
[[File:Бочка кваса Белгород.jpg|thumb|A kvass street vendor in [[Belgorod]], Russia, 2013]]

Although the massive flood of western soft drinks after the fall of the [[USSR]], such as [[Coca-Cola]] and [[Pepsi]], substantially shrank the market share of kvass in Russia, in recent years it has regained its original popularity, often marketed as a national soft drink or "[[Russian nationalism|patriotic]]" alternative to the famous Coca-Cola drink. For example, the Russian company Nikola has promoted its brand of kvass with an advertising campaign emphasizing "[[Cocacolonization|anti-cola-nisation]]." Moscow-based Business Analytica reported in 2008 that bottled kvass sales had tripled since 2005 and estimated that [[per capita]] kvass consumption in Russia would reach three litres in 2008. Between 2005 and 2007, cola's share of the Moscow soft drink market fell from 37% to 32%. Meanwhile, kvass's share more than doubled over the same time period, reaching 16% in 2007. In response, Coca-Cola launched its own brand of kvass in May 2008. This is the first time a foreign company has made an appreciable entrance into the Russian kvass market. Pepsi has also signed an agreement with a Russian kvass manufacturer to act as a distribution agent. The development of new technologies for storage and distribution, and heavy advertising, have contributed to this surge in popularity; three new major brands have been introduced since 2004.<ref name="cola-nisation">[http://www.nzherald.co.nz/business/news/article.cfm?c_id=3&objectid=10521125 ''Russia's patriotic kvass drinkers say no to cola-nisation.''] [[The New Zealand Herald]]. BUSINESS; General. 12 July 2008. {{Dead link|date=February 2022}}</ref>

'''Market shares for Russia (2014)'''
{| class="wikitable sortable"
|-
! Company !! Brand name !! Share [%]<ref>{{cite web|url=http://www.pivnoe-delo.info/2014/09/18/kvas-nikola-stal-markoj-1-v-prodazhax-kvasa-po-rezultatam-letnego-sezona/|title=Россия. Квас "Никола" стал маркой № 1 в продажах кваса по результатам летнего сезона|work=Пивное дело|date=18 September 2014|access-date=17 October 2014|archive-date=23 October 2014|archive-url=https://web.archive.org/web/20141023040519/http://www.pivnoe-delo.info/2014/09/18/kvas-nikola-stal-markoj-1-v-prodazhax-kvasa-po-rezultatam-letnego-sezona/|url-status=live}}</ref>
|-
| {{Interlanguage link|Deka (Russian company)|lt=Deka|ru|Дека (компания)}} || {{Lang|ru|Никола}} {{transliteration|ru|Nikola}}|| 39
|-
| [[Ochakovo (company)|Ochakovo]] || {{Lang|ru|Очаковский}} {{transliteration|ru|Ochakovsky}}|| 18.9
|-
| [[PepsiCo]] || {{Lang|ru|Русский дар}} {{transliteration|ru|Russky dar}}|| 11.6
|-
| [[Carlsberg Group]] || {{Lang|ru|Хлебный край}} {{transliteration|ru|Khlebny kray}}|| 5.5
|-
| [[Coca-Cola, Inc.]] || {{Lang|ru|Кружка и бочка}} {{transliteration|ru|Kruzhka i bochka}}|| 2.1
|-
| Other || || 22.9
|}

===Sweden===
Kvass was also made in Sweden, where it was known as ''{{lang|sv|bröddricka}}'' ({{literal translation|bread drink}}). However, it was very likely limited only to areas where rye bread was the standard bread as opposed to [[crispbread]], which was more common in Western Sweden and did not go stale. ''{{lang|sv|Bröddricka}}'' was still being made in [[Öland]] farms up until 1935.<ref name="Garshol"/>

===China===
[[File:Urumqi Kvass.jpg|thumb|''Kavas'' served in a restaurant in Ürümqi, [[Xinjiang]]]]

In the mid-19th century, kvass was introduced in [[Xinjiang]], where it became known as {{Lang|zh-Latn|kavas}} ({{zh|s=格瓦斯|p=géwǎsī}}) and eventually became one of the region's signature drinks.<ref>{{Cite web |title=Xinjiang native beer-kvass |date=22 December 2021 |url=https://inf.news/en/food/b383650d5c91981b8bb06217f2ca505f.html |publisher=INFNews |access-date=22 December 2021 }}{{Dead link|date=May 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> It is usually consumed cold together with [[barbecue]].<ref>{{Cite magazine |last=Yike |first=Wang |title=Beverages of Xinjiang |date=22 February 2018 |url=https://www.youlinmagazine.com/article/beverages-of-xinjiang/MTA1NA== |magazine=Youlin Magazine |access-date=17 September 2021 |archive-date=18 October 2021 |archive-url=https://web.archive.org/web/20211018113306/https://www.youlinmagazine.com/article/beverages-of-xinjiang/MTA1NA== |url-status=live }}</ref> In 1900, Russian merchant Ivan Churin founded [[Churin and Qiulin|Harbin Churin Food]] ({{zh|s=秋林|p=Qiūlín}}) in [[Harbin]], offering kvass and other specialities, and by 2009, the company was already producing 5,000 tons of kvass a year, making up 90% of the local market. In 2011, it moved its kvass factory to [[Tianjin]], increasing its sales to 20,000 tons in the first year.<ref>{{Cite magazine |title=Chinese Thirst for Kvass Draws Wahaha into Russian Niche |date=15 April 2013 |url=http://goldsea.com/Text/index.php?id=14389 |magazine=[[Goldsea]] |access-date=17 September 2021 |archive-date=29 September 2021 |archive-url=https://web.archive.org/web/20210929020922/http://goldsea.com/Text/index.php?id=14389 |url-status=live }}</ref>

===Elsewhere===
Following the influx of immigrants in the UK due to the [[2004 enlargement of the European Union]], [[Polish shops in the British Isles|shops]] selling cuisine and beverages from [[Central and Eastern Europe]] were established, many of which stock imported (primarily pasteurised) kvass. As a result, since then a number of different flavours of not-pasteurised kvass, fermented using sourdough starter culture, have also become available in the UK in 2023.<ref>{{Cite web|last=Puzorjov|first=Anton|title=The Genuine Kvass: Benefits, Varieties and Comparison With Other Drinks|url=https://quasdrinks.co.uk/blogs/posts/genuine-kvass-benefits-varieties-comparison-with-other-drinks|access-date=2023-12-10|website=Quas Drinks|language=en|archive-date=10 December 2023|archive-url=https://web.archive.org/web/20231210145632/https://quasdrinks.co.uk/blogs/posts/genuine-kvass-benefits-varieties-comparison-with-other-drinks|url-status=live}}</ref> In recent years, kvass has also become more popular in [[Serbia]].<ref>{{Cite web|url=https://theculturetrip.com/europe/serbia/articles/heres-what-to-drink-if-youre-going-to-serbia/|title=Here's What to Drink if You're Going to Serbia|last=Bills|first=John William|website=Culture Trip|date=12 November 2017|access-date=6 July 2019|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512112151/https://theculturetrip.com/europe/serbia/articles/heres-what-to-drink-if-youre-going-to-serbia/|url-status=live}}</ref>

== Nutritional composition ==
Naturally fermented kvass contains 5.9%±0.02 carbohydrates, of which 5.7%±0.02 are sugars (mostly [[fructose]], [[glucose]], and [[maltose]]), as well as 0.71±0.09, 1.28±0.12, and 18.14±0.48&nbsp;mg/100 g of [[thiamine]], [[riboflavin]], and [[Niacin (substance)|niacin]] respectively. In addition to that, 19 different aroma volatile compounds have also been identified in naturally fermented kvass, most notably 4-penten-2-ol (10.05×10<sup>7</sup> PAU), which has a fruity odour; [[carvone]] (2.28×10<sup>7</sup> PAU) originating from [[caraway]] fruits used as an ingredient in rye bread; and [[ethyl octanoate]] (1.03×10<sup>7</sup> PAU), which has an odour of fruit and fat.<ref name="Foodbalt"/>

Traditional kvass made from rye wholemeal bread has been found to have, on average, twice the [[dietary fibre]] content, 60% more [[antioxidant]] activity (due to the addition of [[caramel]] and [[citric acid]] to the bread), and three times less [[reducing sugars|reducing sugar]] content than industrially produced kvass.<ref>{{cite journal |last1=Gambuś |first1=Halina |last2=Mickowska |first2=Barbara |last3=Barton |first3=Henryk J. |last4=Augustyn |first4=Grażyna |date=February 2015 |title=Health benefits of kvass manufactured from rye wholemeal bread |journal=Journal of Microbiology, Biotechnology and Food Sciences |volume=4 |publisher=[[Slovak University of Agriculture]] |issue=3 (special issue) |pages=34–39 |doi=10.15414/jmbfs.2015.4.special3.34-39 |issn=1338-5178 |doi-access=free }}</ref>

Historically, [[alcohol by volume]] (ABV) of kvass varied depending on the ingredients, microbial flora, as well as temperature and length of fermentation,<ref name="Hornsey"/> but nowadays it is usually not higher than 1.5%. The wide availability and consumption of kvass, including by children of all ages, together with the lacking indication of ABV for kvass on the labels and in advertisements, has been named a possible contributor to [[chronic alcoholism]] in the [[former Soviet Union]].<ref>{{cite journal |last=Jargin |first=Sergei V. |date=September–October 2009 |title=Kvass: A Possible Contributor to Chronic Alcoholism in the Former Soviet Union—Alcohol Content Should Be Indicated on Labels and in Advertising |journal=[[Alcohol and Alcoholism]] |page=529 |volume=44 |issue=5 |doi=10.1093/alcalc/agp055|pmid=19734161 |doi-access=free }}</ref>

== Use ==
Apart from drinking, kvass is also used by families as the basis for many dishes.<ref name="Ministerstwo Rolnictwa i Rozwoju Wsi">{{cite web |last=Mucha |first=Sławomir |date=10 October 2018 |title=Kwas chlebowy |url=https://www.gov.pl/web/rolnictwo/kwas-chlebowy |publisher=[[Ministry of Agriculture and Rural Development (Poland)|Ministry of Agriculture and Rural Development of Poland]] |access-date=30 July 2021 |archive-date=6 January 2022 |archive-url=https://web.archive.org/web/20220106154352/https://www.gov.pl/web/rolnictwo/kwas-chlebowy |url-status=live }}</ref> Traditional cold summertime soups of [[Russian cuisine]], such as [[okroshka]],<ref>{{cite book |last=Katz |first=Sandor |author-link=Sandor Katz |title=Wild Fermentation: The Flavor, Nutrition, and Craft of Live-Culture Foods |url=https://archive.org/details/wildfermentation00katz |url-access=limited |publisher=Chelsea Green |year=2003 |location=[[White River Junction, Vermont|White River Junction]], [[Vermont|VA]] |page=[https://archive.org/details/wildfermentation00katz/page/n137 121] |isbn=1-931498-23-7}}</ref> [[botvinya]], and [[tyurya]], are based on kvass.

==Cultural references==
[[File:Продажа кваса 1862.jpg|thumb|Vassiliy Kalistov, ''Street vending of kvass'' (1862), [[Chuvashia|Chuvash State Art Museum]], Russia]]

The name of [[Kvasir]], a wise being in [[Norse mythology]], is possibly related to kvass.<ref>Александр Николаевич Афанасьев (1865–1869). ''Поэтические воззрения славян на природу''. Директ-медиа (2014) том. 1, стр. [https://books.google.com/books?id=r-d3BAAAQBAJ&q=квасир 260]. {{ISBN|978-5-4458-9827-6}} ([[Alexander Afanasyev]]. ''The Poetic Outlook of Slavs about Nature'', 1865–1869; reprinted 2014, p. 260; in Russian)</ref><ref>[[Karl Joseph Simrock]]. ''Handbuch der deutschen Mythologie mit Einschluss der nordischen'', 1st edition (1855), p. [https://archive.org/details/bub_gb_EhxBAAAAcAAJ_2/page/n99 272] or 2nd edition (1864), p. [http://babel.hathitrust.org/cgi/pt?id=hvd.32044089074793;view=1up;seq=258 244] {{Webarchive|url=https://web.archive.org/web/20220428173934/https://babel.hathitrust.org/cgi/pt?id=hvd.32044089074793;view=1up;seq=258 |date=28 April 2022 }}. Bonn, Marcus.</ref><ref>[[J.J. Mikkola|Jooseppi Julius Mikkola]]. ''Bidrag till belysning af slaviska lånord i nordiska språk''. [[Arkiv för nordisk filologi]], vol.&nbsp;19 (1903), p. [https://runeberg.org/anf/1903/0339.html 331] {{Webarchive|url=https://web.archive.org/web/20230616015631/http://runeberg.org/anf/1903/0339.html |date=16 June 2023 }}.</ref><ref>[[Georges Dumézil]] (1974). ''Gods of the Ancient Northmen'', p. [https://books.google.com/books?id=rurD1yd0Ok0C&q=kvas%20kvasir 21] {{Webarchive|url=https://web.archive.org/web/20231030024132/https://books.google.com/books?id=rurD1yd0Ok0C&q=kvas%20kvasir |date=30 October 2023 }}. University of California Press. {{ISBN|978-0-520-03507-2}}</ref><ref>[[Jan de Vries (linguist)|Jan de Vries]] (2000). ''Altnordisches etymologisches Wörterbuch'', p. [https://books.google.com/books?id=so8eAAAAIAAJ&q=kvasir&pg=PA319 336] {{Webarchive|url=https://web.archive.org/web/20231030024129/https://books.google.com/books?id=so8eAAAAIAAJ&q=kvasir&pg=PA319 |date=30 October 2023 }}. 4th edition, Leiden (in German)</ref>

There is a Russian expression, {{Lang|ru|Перебиваться с хлеба на квас}} (literally 'to clamber from bread to kvass'), which means 'to live from hand to mouth' or to 'scrape by'<ref>{{Cite book |last=Lubensky |first=Sophia |date=2013 |title=Russian-English Dictionary of Idioms |url=https://books.google.com/books?id=vOh0AgAAQBAJ&pg=PA695 |publisher=[[Yale University Press]] |edition=Revised |page=695|isbn=9780300162271 }}</ref> referring to the frugal practice amongst the poor peasants of making kvass from stale leftovers of [[rye bread]].<ref>[[Svyatoslav Loginov]], [http://www.rusf.ru/loginov/books/story07.htm "We Used to Bake Blini..." ("Бывало пекли блины...")] {{Webarchive|url=https://web.archive.org/web/20100104200432/http://rusf.ru/loginov/books/story07.htm |date=4 January 2010 }} {{in lang|ru}}</ref> Another kvass-related term in Russian is "{{Interlanguage link|kvass patriotism|ru|Квасной патриотизм}}" (квасной патриотизм) dating back to an 1823 letter by the Russian poet [[Pyotr Vyazemsky]] who defined it as "unqualified praise of everything that is your own".<ref>{{cite web |last=Latour |first=Abby |date=29 October 2018 |title=Kvas Patriotism in Russia: Cultural Problems, Cultural Myths |url=https://jordanrussiacenter.org/event-recaps/kvas-patriotism-in-russia-cultural-problems-cultural-myths/ |publisher=Jordan Center for the Advanced Study of Russia |access-date=4 January 2022 |archive-date=2 March 2022 |archive-url=https://web.archive.org/web/20220302020748/https://jordanrussiacenter.org/event-recaps/kvas-patriotism-in-russia-cultural-problems-cultural-myths/ |url-status=dead }}</ref>

In the [[Polish language]], several traditional sayings that reference {{Lang|pl|kwas chlebowy}} exist.<ref name="zaława" /> There is also an old Polish folk rhyming song. It shows the history of kvass in the country as having been drunk by generations of Polish [[Reaper#Hand reaping|reapers]] as a thirst-quenching beverage used during periods of hard work during the harvest season, long before it became popular as a medicinal drink among the [[szlachta]]. The song goes as follows:<ref>{{cite web|url=http://smakuj.lubelskie.pl/en/lista-produktow-tradycyjnych?p_p_id=122_INSTANCE_JEMP7Dvbq5jo&p_p_lifecycle=0&p_p_state=normal&p_p_mode=view&p_p_col_id=column-1&p_p_col_count=1&p_r_p_564233524_resetCur=true&p_r_p_564233524_categoryId=369008|title=Kwas chlebowy sapieżyński kodeński|last=Śliwińska|first=Jolanta|date=29 June 2017|website=Smakuj Lubelskie|access-date=22 December 2019}}{{Dead link|date=May 2022 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>
{{Verse translation|Od dawien dawna słynie napój zdrowy:
kwas chlebowy,
pajda chleba za pazuchę,
bukłak kwasu
i chłop gotów w pole.
W gorącą posuchę.|A healthy drink has long been renowned:
bread kvass,
a chunk of bread below the armpit,
a goatskin of kvass
and the peasant is ready for the fields.
Into a hot drought.|head1=Original Polish lyrics|head2=English translation|lang=pl}}{{clear}}

In the Polish village of [[Zaława]], there is a customary game known as {{Lang|pl|wulkan}} ('volcano') that is associated with the beverage. The fermentation of sugars makes kvass slightly carbonated, thus, when shaken or heated, it can cause the liquid to suddenly and rapidly rise out of an open vessel. Playing ''wulkan'' consists of vigorously shaking a bottle of kvass shortly before handing it to someone else who is going to drink it; the sudden "shooting out" of the beverage onto the person opening the bottle is a source of entertainment for the youth of Zaława and a well-known prank during regional festivities.<ref name="zaława" />

In Tolstoy's ''[[War and Peace]]'', French soldiers are aware of kvass on entering Moscow, enjoying it but referring to it as "pig's lemonade".<ref>''[[War and Peace]]''. [[Leo Tolstoy]]. Book 10, chapter 29, Pennsylvania State University translation.</ref> In [[Sholem Aleichem]]'s ''[[Motl, Peysi the Cantor's Son]]'', diluted kvass is the focus of one of Motl's older brother's [[get-rich-quick scheme]]s.<ref>{{cite news |last=Vered |first=Ronit |date=15 November 2012 |title=A Touch of Kvass |url=https://www.haaretz.com/.premium-restaurants-a-touch-of-kvass-1.5198468 |newspaper=[[Haaretz]] |access-date=14 July 2020 |archive-date=3 August 2020 |archive-url=https://web.archive.org/web/20200803142628/https://www.haaretz.com/.premium-restaurants-a-touch-of-kvass-1.5198468 |url-status=live }}</ref>

==Non-bread varieties==
[[File:Beet root kvas.jpg|thumb|Beetroot kvas]]
A traditional drink made in Ukraine was [[pear]] and [[apple]] kvas, produced by keeping dried fruit in water for two months. This kind of drink was popular at banquets and also kept the population from consuming low-quality water.<ref>{{Cite web|title=Фруктові смаки "Енеїди"|date=2025-08-05|url=https://localhistory.org.ua/texts/statti/fruktovi-smaki-eneyidi/|access-date=2025-08-08}}</ref> Another popular traditional speciality of Ukraine is [[beetroot]] kvas, which could be consumed as a drink or used as an ingredient of other dishes, most famously [[borshch]].<ref>{{Cite web|title=Кулінарний фронт українців|date=2021-03-26|url=https://localhistory.org.ua/videos/bez-bromu/borshch-ta-inshi-garazdi-klopotenko/|access-date=2025-08-08}}</ref><ref>{{Cite web|title=Що таке «українська кухня»? Історія, страви, смаки|url=https://obarykada.com/chasopys/shho-take-ukrayinska-kuhnya-istoriya-stravy-smaky/|access-date=2025-08-13}}</ref>

== See also ==
{{Portal|Beer}}
{{div col|colwidth=30em}}
* [[Small beer]]
* [[Borș (bran)]]
* [[Boza]]
* [[Brottrunk]]
* [[Chicha]]
* [[Ginger ale]]
* [[Kefir]]
* [[Water kefir]]
* [[Kombucha]]
* [[Malta (soft drink)|Malta]]
* [[Mors (drink)|Mors]]
* [[Podpiwek]]
* [[Pruno]]
* [[Rejuvelac]]
* [[Rivella]]
* [[Tepache]]
{{div col end}}

==References==
{{Reflist}}

==External links==
*{{Commons category-inline|Kvass}}
*{{Wiktionary-inline|kvass}}

{{Beer styles}}
{{Authority control}}

[[Category:Fermented drinks]]
[[Category:Rye-based drinks]]
[[Category:Ukrainian drinks]]
[[Category:Chinese drinks]]
[[Category:Estonian drinks]]
[[Category:Latvian drinks]]
[[Category:Lithuanian drinks]]
[[Category:Polish drinks]]
[[Category:Belarusian drinks]]
[[Category:Russian drinks]]
[[Category:Serbian drinks]]
[[Category:Soviet cuisine]]
[[Category:Uyghur cuisine]]