Still

Still

A still is a permanent apparatus used to distill miscible or immiscible (eg. steam distillation) liquid mixtures by heating to selectively boil and then cooling to condense the vapor. Stills have been used to produce perfume and medicine, Water for Injection (WFI) for pharmaceutical use, generally to separate and purify different chemicals, and most famously, to produce distilled beverages containing ethyl alcohol.

Application

Swan necked copper stills in the Glenfiddich distillery
Old Ukrainian vodka still
Zambian artisanal Kachasu still and cooler

Since ethyl alcohol boils at a lower temperature than water, a common application of the process of distillation is to produce strong alcoholic drinks. Usually a still used for this purpose is made of copper, since it removes sulfur-based compounds from the alcohol that would make it unpleasant to drink. Modern stills are made of stainless steel with copper innards (piping, for example, will be lined with copper along with copper plate inlays along still walls). Using this combination of metals is much cheaper as it prevents erosion of the entire vessel and lowers copper levels in the waste product (which in large distilleries is processed to become animal feed). All copper stills will require repairs about every 8 years because of copper erosion from the compounds it is designed to remove; this erosion is therefore unavoidable. The alcohol industry was the first to use anything close to a modern distillation apparatus and led the way in developing what is now a large part of the chemical industry.

There is also an increasing usage of 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, 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. 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, poteen.

See also


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  • STILL — GmbH Год основания 1920 год Ключевые фигуры Dr. Rolf Karg (председательствующий), Bert Jan Knoef, Dr. Lorenz Zwingmann Тип общество с ограниченной ответств …   Википедия

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  • Still — Still, a. [Compar. {Stiller}; superl. {Stillest}.] [OE. stille, AS. stille; akin to D. stil, OS. & OHG. stilli, G. still, Dan. stille, Sw. stilla, and to E. stall; from the idea of coming to a stand, or halt. Cf. {Still}, adv.] 1. Motionless; at… …   The Collaborative International Dictionary of English

  • Still — Still, adv. [AS. stille quietly. See {Still}, a. The modern senses come from the idea of stopping and staying still, or motionless.] 1. To this time; until and during the time now present; now no less than before; yet. [1913 Webster] It hath been …   The Collaborative International Dictionary of English

  • Still — steht für Ortsnamen: die Gemeinde Still im Elsass, siehe Still (Bas Rhin) die Katastralgemeinde Still (Gemeinde Hofkirchen), Oberösterreich den Familiennamen folgender Personen: Andrew Taylor Still, (1828–1917), Begründer der Osteopathie Clyfford …   Deutsch Wikipedia

  • still — still1 [stil] adj. [ME < OE stille, akin to Ger still < IE * stelnu < base * stel , to place, set up, standing, immobile > STALK1, STALL1, L locus, place, Gr stēlē, a post] 1. without sound; quiet; silent 2. hushed, soft, or low in… …   English World dictionary

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  • Still — adj Still, stilly, quiet, silent, noiseless can all mean making no stir or noise. Still applies to what is motionless or at rest, often with the further implication of hush or absence of sound; sometimes one implication is stressed, sometimes the …   New Dictionary of Synonyms

  • Still — Still, v. t. [imp. & p. p. {Stilled}; p. pr. & vb. n. {Stilling}.] [AS. stillan, from stille still, quiet, firm. See {Still}, a.] 1. To stop, as motion or agitation; to cause to become quiet, or comparatively quiet; to check the agitation of; as …   The Collaborative International Dictionary of English

  • Still — Still, er, este, oder auch Stille, mit dem e euphonico, er, ste, adj. et adv. ein Wort, welches eine Abwesenheit sowohl der Bewegung, als des Lautes, des Geräusches bezeichnet. 1. Eigentlich. (1) In Absicht auf die Bewegung, keine Bewegung habend …   Grammatisch-kritisches Wörterbuch der Hochdeutschen Mundart

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