Still
From Free net encyclopedia
- For other uses, see Still (disambiguation).
The term 'still' is a contraction of the verb 'to distill'.
A still is an apparatus used to distill miscible or immiscible (eg. steam distillation) liquids by heating and then cooling. It has 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 alcohol.
Application
Main article: distilled beverages
Image:Glenfiddich Distillery stills.jpg
Since 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, as it does not give taste to the drink, resists acid, and conducts heat.
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 rum are both distilled by this method, then diluted to concentrations appropriate for human consumption.
The alcoholic product of illegal stills in the United States is commonly referred to as moonshine.