Editing Sake (section)

=== ''Kōji-kin'' ===
==== ''Aspergillus oryzae'' (yellow ''kōji'') ====
''[[Aspergillus oryzae]]'' spores are another important component of sake. ''A. oryzae'' is an enzyme-secreting [[fungus]].<ref name="Machida-2008">{{Cite journal|last1=Machida|first1=Masayuki|last2=Yamada|first2=Osamu|last3=Gomi|first3=Katsuya|date=August 2008|title=Genomics of Aspergillus oryzae: Learning from the History of Koji Mold and Exploration of Its Future|journal=DNA Research |volume=15|issue=4|pages=173–183|doi=10.1093/dnares/dsn020|issn=1340-2838|pmc=2575883|pmid=18820080}}</ref> In Japan, ''A. oryzae'' is used to make various fermented foods, including ''[[miso]]'' (a paste made from soybeans) and {{Nihongo3|||shoyu}} ([[soy sauce]]).<ref name="Machida-2008" /> It is also used to make alcoholic beverages, notably sake.<ref name="Machida-2008" /> During sake brewing, spores of ''A. oryzae'' are scattered over steamed [[rice]] to produce {{Nihongo3|||kōji}} (rice in which ''A. oryzae'' spores are cultivated).<ref name="Tengu Sake">{{Cite web|url=https://www.tengusake.com/sake-guide/how-sake-is-made/|title=How sake is made|website=Tengu Sake|language=en-GB|access-date=2019-08-08}}</ref> Under warm and moist conditions, the ''A. oryzae'' spores germinate and release [[amylase]]s (enzymes that convert the rice [[starch]]es into maltose and glucose). This conversion of starch into simple sugars (e.g., glucose or maltose) is called [[saccharification]]. Yeast then [[fermentation|ferment]] the glucose and other sugar into [[ethanol|alcohol]].<ref name="Tengu Sake" /> Saccharification also occurs in [[beer]] brewing, where [[mashing]] is used to convert starches from [[barley]] into maltose.<ref name="Tengu Sake" /> However, whereas fermentation occurs ''after'' saccharification in beer brewing, saccharification (via ''A. oryzae'') and fermentation (via yeast) occur ''simultaneously'' in sake brewing (see "Fermentation" below).<ref name="Tengu Sake" />

As ''A. oryzae'' is a microorganism used to manufacture food, its safety profile concerning humans and the environment in sake brewing and other food-making processes must be considered. Various health authorities, including [[Health Canada]] and the [[United States|U.S.]] [[Food and Drug Administration]] (FDA), consider ''A. oryzae'' generally safe for use in food fermentation, including sake brewing.<ref name="Machida-2008" /> When assessing its safety, it is important to note that ''A.'' ''oryzae'' lacks the ability to produce toxins, unlike the closely related ''[[Aspergillus flavus]]''.<ref name="Machida-2008" /> To date, there have been several reported cases of animals (e.g. [[parrot]]s, a [[horse]]) being infected with ''A. oryzae''.<ref name="Government of Canada-2017">{{Cite web|url=http://publications.gc.ca/site/archivee-archived.html?url=http://publications.gc.ca/collections/collection_2017/eccc/En14-267-2017-eng.pdf|title=Final Screening Assessment for ''Aspergillus oryzae'' ATCC 11866 |date=January 2017 |last=Government of Canada |access-date=2019-08-08|archive-url=https://web.archive.org/web/20191023170107/http://publications.gc.ca/collections/collection_2017/eccc/En14-267-2017-eng.pdf |archive-date=Oct 23, 2019 |url-status=dead}}</ref> In these cases the animals infected with ''A. oryzae'' were already weakened due to predisposing conditions such as recent injury, illness or stress, hence were susceptible to infections in general.<ref name="Government of Canada-2017" /> Aside from these cases, there is no evidence to indicate ''A. oryzae'' is a harmful pathogen to either plants or animals in the scientific literature.<ref name="Government of Canada-2017" /> Therefore, Health Canada considers ''A. oryzae'' "unlikely to be a serious hazard to [[livestock]] or to other organisms," including "healthy or debilitated humans."<ref name="Government of Canada-2017" /> Given its safety record in the scientific literature and extensive history of safe use (spanning several hundred years) in the Japanese food industry, the FDA and [[World Health Organization]] (WHO) also support the safety of ''A. oryzae'' for use in the production of foods like sake.<ref name="Machida-2008" /> In the US, the FDA classifies ''A.oryzae'' as a [[Generally recognized as safe|Generally Recognized as Safe]] (GRAS) organism.<ref name="Machida-2008" />

==== ''Aspergillus kawachii'' (white ''kōji'') ====
In addition to ''Aspergillus oryzae'' (yellow ''kōji''), ''Aspergillus kawachii'' (white ''kōji'') and ''Aspergillus luchuensis'' (black ''kōji''), which are used to brew ''[[shōchū]]'' and ''[[awamori]]'', have been used to brew sake since the 21st century.<ref name="kawachii220520">{{cite web|url=https://sakestreet.com/ja/media/learn-shiro-koji-and-kuro-koji|archive-url=https://web.archive.org/web/20220930061200/https://sakestreet.com/ja/media/learn-shiro-koji-and-kuro-koji|script-title=ja:日本酒造りにもたらされた「クエン酸」による変革!! - 白麹、黒麹仕込みの日本酒を学ぶ|language=ja|publisher=Sake Street|date=22 May 2022|archive-date=30 September 2022|access-date=9 April 2023}}</ref>

From the 1980s, research was conducted to brew sake using ''[[Aspergillus luchuensis|Aspergillus kawachii]]'' (white ''kōji''), which is used to make ''shōchū'',<ref>{{cite journal|url=https://www.jstage.jst.go.jp/article/jbrewsocjapan1988/85/2/85_2_114/_article|archive-url=https://web.archive.org/web/20180605164117/https://www.jstage.jst.go.jp/article/jbrewsocjapan1988/85/2/85_2_114/_article|title=Fermentation Characteristics of Sake Mash made by Using Rice Koji Prepared with Aspergillus kawachii |first1=Akihiro |last1=Nakamura |first2=Naoki |last2=Iimori |first3=Shigetoshi |last3=Sudo |first4=Shigeaki |last4=Mikami |first5=Kiyoshi |last5=Ito |first6=Takeaki |last6=Ishikawa |journal=Journal of the Brewing Society of Japan |volume=85 |date=1990 |issue=2 |pages=114–119 |doi=10.6013/jbrewsocjapan1988.85.114 |doi-access=free |archive-date=5 June 2018|access-date=9 April 2023}}</ref> and sake made with ''Aspergillus kawachii'' became popular when Aramasa Co, Ltd. released "Amaneko" using ''Aspergillus kawachii'' in 2009. ''Aspergillus kawachii'' produces about 10 times more [[citric acid]] than ''Aspergillus oryzae'', and thus has a strong ability to suppress the growth of bacteria that damage the flavor of sake. It also imparts a sour, citrus-like flavor to sake. Because it produces so much citric acid, older sake-making methods such as ''[[#Methods of preparing the starter mash|kimoto]]'' or ''[[#Methods of preparing the starter mash|yamahai]]'' can produce a starter mash as quickly as modern ''[[#Methods of preparing the starter mash|sokujō]]''. ''Kimoto'' and ''yamahai'' do not add artificial lactic acid, which allows them to be labeled "additive-free," giving them a marketing advantage when exporting.<ref name="kawachii220520"/>

==== ''Aspergillus luchuensis'' (black ''kōji'') ====
As of 2022, sake made with ''[[Aspergillus luchuensis]]'' (black ''kōji'') is not as popular as sake made with ''Aspergillus kawachii''. It produces more citric acid than ''Aspergillus kawachii''. However, it produces less [[amino acid|amino acids]], which produce complex flavors such as [[umami]], bitterness, and sweetness. ''Aspergillus luchuensis'' also produces more [[peptide|peptides]], which results in a bitter taste. This combines with a strong sour taste from the citric acid, which is sometimes compared to strawberry or [[red wine]].<ref name="kawachii220520"/>