Editing Sake (section)

=== Sake yeast ===
[[File:Sake made with Kyōkai yeast Akairo kōbo for pink nigorizake, 協会酵母清酒用赤色酵母（桃色濁り酒用）.jpg|thumb|150px|Sake made with Kyokai yeast "Akairo kōbo" for pink ''[[nigori|nigorizake]]''<ref name="akairo2"/>]]
Sake [[yeast]] is so important in sake brewing that it is said to affect the flavor of sake more than rice. In sake brewing, ''kōji'' breaks down rice starch into glucose, and yeast is responsible for the fermentation process that converts the glucose into alcohol. Yeast has a significant impact on the flavor of sake by producing [[Ethyl hexanoate|ethyl caproate]], [[isoamyl acetate]], and other flavor compounds and acids as well as alcohol during the fermentation process.<ref name="ss051219">{{Cite web |author=Kohei Ninohe|script-title=ja:実は味の決め手？「酵母」とは - 日本酒造りにおける役割と種類を徹底解説|language=ja|url=https://sakestreet.com/ja/media/learn-yeast-for-sake-1|archive-url=https://web.archive.org/web/20240915004906/https://sakestreet.com/ja/media/learn-yeast-for-sake-1|publisher=SAKE Street, Inc.|date=5 December 2019|archive-date=15 September 2024|access-date=8 February 2025 }}</ref>

The various types of yeast used in sake brewing belong to the species ''[[Saccharomyces cerevisiae]]'', and a large number of yeasts have been developed in Japan.<ref name="ss051219"/> For example, the laboratory of the {{ill|Hakutsuru Sake Brewery|ja|白鶴酒造}} has 400 types of yeast.<ref name="st140120">{{Cite web |author=Akiko Watabe|script-title=ja:400種以上の“自社開発酵母”が日本酒の新たな個性をつくる─ 革新的な商品を次々と生み出す白鶴酒造が培った酵母研究|language=ja|url=https://jp.sake-times.com/special/pr/pr_hakutsuru2_004|archive-url=https://web.archive.org/web/20240910114946/https://jp.sake-times.com/special/pr/pr_hakutsuru2_004|publisher=Sake Times|date=14 January 2020|archive-date=10 September 2024|access-date=8 February 2025 }}</ref>

Before the modernization of Japan, breweries used yeasts that were native to each brewery. The yeasts evolved uniquely in each brewery as they competed for survival by mixing with microorganisms that became airborne and attached to the human body during the sake brewing process. Because some of these yeasts were not suitable for brewing sake, the quality of sake varied from brewery to brewery and from period to period.<ref name="hi0220120">{{Cite web |author=|script-title=ja:日本酒の「酵母」の歴史|language=ja|url=https://harimacountry.com/archives/330|archive-url=https://web.archive.org/web/20240725194628/https://harimacountry.com/archives/330|publisher=[[Himeji|Himeji City]]|date=21 January 2020|archive-date=25 July 2024|access-date=8 February 2025 }}</ref><ref name="as190214">{{Cite web |author=|script-title=ja:酵母の話（1）|language=ja|url=https://www.osake.or.jp/sake/140219.html|archive-url=https://web.archive.org/web/20230908021908/https://www.osake.or.jp/sake/140219.html|publisher=Akita Sake Brewers Association|date=19 February 2014|archive-date=8 September 2023|access-date=8 February 2025 }}</ref><ref name="kt291222">{{Cite web |author=|script-title=ja:酵母の発見～酵母の歴史を巡る～|language=ja|url=https://tc-kyoto.or.jp/magazine/history-kyotokobo-ep02/|archive-url=https://web.archive.org/web/20241005065706/https://tc-kyoto.or.jp/magazine/history-kyotokobo-ep02/|publisher= Kyoto Municipal Institute of Industrial Technology and Culture|date=29 December 2022|archive-date=5 October 2024|access-date=8 February 2025 }}</ref>

In 1895, Dr. Kikuji Yabe isolated the first ''Saccharomyces sake'' yeast suitable for brewing sake. In 1904, the government established the National Brewing Laboratory and began detailed studies of yeast.
In 1906, the Brewing Society of Japan was founded, and a system was established whereby any superior yeast discovered was registered as ''Kyokai-kōbo'' ("Kyokai yeast", "Association yeast") and distributed to breweries throughout Japan. Kyokai yeast No. 7 and No. 9 are particularly popular. In response to the popularity of ''ginjō-shu'' since the 1980s, various aromatic yeasts have been developed. Today, the Brewing Society of Japan, research institutes in each prefecture, and breweries continue to develop a variety of yeasts, and an increasing number of breweries are making sake from yeasts found in flowers.<ref name="hi0220120"/><ref name="as190214"/><ref name="kt291222"/>

Some sake yeasts can also color sake. For example, Kyokai yeast "Akairo kōbo", isolated in 1984, can produce pink ''[[nigori]]'' or ''[[#Different handling after fermentation|origarami]]'' sake by producing a red pigment during fermentation. This yeast is not fertile and temperature control is difficult, but it adds a sweet strawberry flavor to the sake.<ref name="akairo">{{Cite web|script-title=ja:清酒用赤色酵母（桃色濁り酒用）|language=ja|url=https://www.jozo.or.jp/yeast/red/|archive-url=https://web.archive.org/web/20241011234433/https://www.jozo.or.jp/yeast/red/|publisher=The Brewing Society of Japan|date=|archive-date=11 October 2024|access-date=15 February 2025 }}</ref><ref name="akairo2">{{Cite web|script-title=ja:ちえびじん LOVE PINK|language=ja|url=https://www.jizake.com/c/sake/chiebijin/Sake9100_1800|archive-url=https://web.archive.org/web/20240916025032/https://www.jizake.com/c/sake/chiebijin/Sake9100_1800|publisher=The Brewing Society of Japan|date=|archive-date=16 September 2024|access-date=15 February 2025 }}</ref>