Editing Still

{{short description|Apparatus used to distill liquid mixtures}}
{{About|distilling apparatus}}
{{More citations needed|date=August 2021}}
[[File:Glenfiddich Distillery stills.jpg|thumb|upright=1.25|Swan-necked copper [[pot still]]s in the [[Glenfiddich]] distillery]]
[[File:A_still_at_Mackmyra_Whisky_Distillery.jpg|250px|thumbnail|right|A still at [[Mackmyra Whisky|Mackmyra Whisky Distillery]]]]
[[File:Coffey Still.JPG|thumb|upright|[[Column still]] from [[Kilbeggan Distillery]] in County Westmeath in Ireland.]]

A '''still''' is an apparatus used to [[distillation|distill]] [[liquid]] mixtures by heating to selectively [[Boiling|boil]] and then cooling to [[Condensation|condense]] the [[vapor]].<ref>{{cite web | url=http://jupiter.plymouth.edu/~wwf/distillation.htm | title=DISTILLATION APPARATUS | publisher=Plymouth State University | access-date=22 March 2014}}</ref> A still uses the same concepts as a basic [[Distillation#Laboratory_procedures|distillation apparatus]], but on a much larger scale. Stills have been used to produce [[perfume]] and [[medicine]], [[water for injection]] (WFI) for pharmaceutical use, generally to separate and purify different chemicals, and to produce [[distilled beverage]]s containing [[ethanol]].

==Application==
{{Main|Distilled beverage}}
Since [[ethanol]] [[boiling point|boil]]s at a much lower [[temperature]] than [[water]], [[simple distillation]] can separate ethanol from water by applying heat to the mixture.  Historically, a [[copper]] vessel was used for this purpose, since copper removes undesirable [[sulfur]]-based compounds from the alcohol.  However, many modern stills are made of stainless steel pipes with copper linings to prevent erosion of the entire vessel and lower copper levels in the waste product (which in large distilleries is processed to become animal feed).<ref>{{cite journal | url=https://academic.oup.com/nutritionreviews/article-abstract/2/12/356/1850381?redirectedFrom=PDF | title=Distillation by-Products as Animal Feeds | journal=Nutrition Reviews | date=1944 | volume=2 | issue=12 | pages=356–358 | publisher=Oxford University Press| doi=10.1111/j.1753-4887.1944.tb08165.x | access-date=10 May 2021| url-access=subscription }}</ref> Copper is the preferred material for stills because it yields an overall better-tasting spirit. The taste is improved by the chemical reaction between the copper in the still and the sulfur compounds created by the yeast during fermentation. These unwanted and flavor-changing sulfur compounds are chemically removed from the final product resulting in a smoother, better-tasting drink.  All copper stills will require repairs about every eight years due to the precipitation of [[copper(II)_sulfate| copper-sulfur compounds]]. The beverage industry was the first to implement a modern distillation apparatus and led the way in developing equipment standards which are now widely accepted in the chemical industry.

[[File:UkrainianVodkaStill.jpg|thumb|Old Ukrainian vodka still]]
[[File:Kachasu.jpg|thumb|Zambian artisanal ''[[Kachasu]]'' still and cooler]]

There is also an increasing usage of the distillation of [[gin]] under glass and [[PTFE]], and even at reduced pressures, to facilitate a fresher product.  This is irrelevant to alcohol quality because the process starts with triple distilled grain alcohol, and the distillation is used solely to harvest botanical flavors such as [[limonene]] and other [[terpene]] like compounds.  The ethyl alcohol is relatively unchanged.

The simplest standard [[distillation]] apparatus is commonly known as a [[pot still]], consisting of a single heated chamber and a vessel to collect purified alcohol. A pot still incorporates only one [[condensation]], whereas other types of distillation equipment have multiple stages which result in higher purification of the more volatile component (alcohol). Pot still distillation gives an incomplete [[Separation process|separation]], but this can be desirable for the flavor of some [[distilled beverages]].

If a purer distillate is desired, a [[reflux still]] is the most common solution. Reflux stills incorporate a [[fractionating column]], commonly created by filling copper vessels with glass beads to maximize available [[surface area]].<ref name=Kister>{{cite book|author=Kister, Henry Z.| title=[[Distillation Design]]|edition=1st|publisher=McGraw-Hill |year=1992|isbn=0-07-034909-6}}</ref> As alcohol boils, condenses, and reboils through the column, the effective number of distillations greatly increases. [[Vodka]] and [[gin]] and other neutral grain spirits are distilled by this method, then diluted to concentrations appropriate for human consumption.

Alcoholic products from home distilleries are common throughout the world but are sometimes in violation of local statutes.  The product of illegal stills in the [[United States]] is commonly referred to as [[moonshine]] and in [[Ireland]], [[poitín]]. However, poitín, although made illegal in 1661, has been legal for export in Ireland since 1997. Note that the term [[moonshine]] itself is often misused as many believe it to be a specific kind of high-[[Alcohol_proof|proof]] alcohol that was distilled from corn, but the term can refer to any illicitly distilled alcohol.<ref>{{cite web | url=http://www.brewhaus.com/Moonshine-Still-and-Alcohol-Stills-C150.aspx | title=About Moonshine Stills and Alcohol Stills | access-date=14 November 2014}}</ref>
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==See also==
{{Div col|small=yes}}
* [[Distillation]]
*[[Distilled water]]
*[[Retort]]
*[[Alembic]]
*[[Column still]]
*[[Pot still]]
*[[Reflux still]]
*[[Solar still]]
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==References==
{{reflist}}

==External links==
{{Commons category|Distillation apparatus}}
*[https://www.youtube.com/watch?v=TywPjx3VHeM Moonshine Still ] Moonshine Still Ghost from the past - Video
*{{cite EB1911|wstitle=Still}}
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{{Distillation}}
{{Use dmy dates|date=March 2017}}

[[Category:Distillation]]
[[Category:Separation processes]]
[[Category:Laboratory equipment]]
[[Category:Chemical equipment]]
[[Category:Firing techniques]]