Editing Yeast (section)

==== Wine ====
{{Main|Yeast in winemaking}}
[[File:Schramsberg Vineyards, July 2019-7609.jpg|thumb|Yeast in a bottle during sparkling wine production at [[Schramsberg Vineyards]], Napa]]
Yeast is used in [[winemaking]], where it converts the sugars present ([[glucose]] and [[fructose]]) in [[grape juice]] ([[must]]) into ethanol. Yeast is normally already present on grape skins. [[Fermentation (wine)|Fermentation]] can be done with this endogenous "wild yeast",<ref name="Ross-1997"/> but this procedure gives unpredictable results, which depend upon the exact types of yeast species present. For this reason, a pure yeast culture is usually added to the must; this yeast quickly dominates the fermentation. The wild yeasts are repressed, which ensures a reliable and predictable fermentation.<ref name="González-2001"/>

Most added wine yeasts are strains of ''S. cerevisiae'', though not all strains of the species are suitable.<ref name="González-2001"/> Different ''S.&nbsp;cerevisiae'' yeast strains have differing physiological and fermentative properties, therefore the actual strain of yeast selected can have a direct impact on the finished wine.<ref name="Dunn-2005"/> Significant research has been undertaken into the development of novel wine yeast strains that produce atypical flavour profiles or increased complexity in wines.<ref name=YeastRef14/><ref name="McBryde-2006"/>

The growth of some yeasts, such as ''[[Zygosaccharomyces]]'' and ''[[Brettanomyces]]'', in wine can result in [[wine fault]]s and subsequent spoilage.<ref name="Loureiro-2003"/> ''Brettanomyces'' produces an array of [[metabolite]]s when growing in wine, some of which are volatile [[phenol]]ic compounds. Together, these compounds are often referred to as "''Brettanomyces'' character", and are often described as "[[antiseptic]]" or "barnyard" type aromas. ''Brettanomyces'' is a significant contributor to wine faults within the wine industry.<ref name="Lamar"/>

Researchers from the [[University of British Columbia]], Canada, have found a new strain of yeast that has reduced [[amine]]s. The amines in [[Wine color|red wine]] and [[Chardonnay]] produce off-flavors and cause headaches and hypertension in some people. About 30% of people are sensitive to biogenic amines, such as [[histamine]]s.<ref>{{Cite news|title=Eureka! Vancouver scientists take the headache out of red wine |url=https://vancouversun.com/health/Eureka+Vancouver+scientists+take+headache+wine/4281742/story.html |author=Shore R |date=15 February 2011 |work=[[The Vancouver Sun]] |archive-url=https://web.archive.org/web/20110217024652/http://www.vancouversun.com/health/Eureka%2BVancouver%2Bscientists%2Btake%2Bheadache%2Bwine/4281742/story.html |archive-date=17 February 2011 |url-status=dead }}</ref>