It is assumed by the historians that distillation of whiskey started by Babylonians in Mesopotamia in the 2nd millennium BC. But there is no documented proof to substantiate this assumption of the historians. There are many other assumptions regarding distillation of whiskey but the earliest record of distillation of alcohol is in Italy in the 13th century, where alcohol was distilled for wine. Its use spread through medieval monasteries for treatment of diseases like colic and smallpox and other medicinal purposes.

Whiskey is usually produced in grain-growing areas. The difference is related to base product, alcoholic content and quality. There are basically two types of whiskey

Malt Whiskey– which is primarily made from malted barley, and

Grain whiskey-which is primarily made of grains.

Whiskey is a complex beverage that contains a vast range of flavoring compounds of which around two to three hundred can easily be detected by chemical analysis. The flavoring chemicals include “carbonyl compounds, alcohols, carboxylic acids and their esters, nitrogen- and sulfur-containing compounds, tannins and other polyphenolic compounds, terpenes, and oxygen-containing heterocyclic compounds” and esters of fatty acids.  The nitrogen compounds include pyridines, picolines, and pyrazines.

The determination of flavoring for whiskey can be partially determined by the presence of congeners and fusel oils. Fusel oils are higher alcohols than ethanol, and mildly toxic and have a strong and disagreeable smell and taste.

Whiskey is often chill-filtered. It is chilled to precipitate the fatty acid esters and then it is filtered to remove them. That is the normal process of bottling most whiskeys. But on certain conditions there are whiskeys that are specified to be un-chill filtered or be non-chill filtered. This is primarily done for cosmetic reasons. When un-chilled whiskeys are stored in cold temperature or cold water is added to them then they become cloudy. It is perfectly normal.