Definitions of whisky over countries are similar. Below are the basic requirements:

1. Produced by distillation of grains have gone through mashing and fermentation
2. Distilled whisky needs to be aged in oak casks for years. Only water can be added to adjust the alcoholic strength. In most countries including Scotland, whisky must be matured for a minimum of 3 years, while in America, the legal minimum is 2 years.
3. Cask strength whisky can be bottled with or without blending. No other ingredients can be added except for legalised food colouring (mainly plain caramel E105a). There are exceptions like Canada's 9.09% rule, allowing producers to add up to 9.09% of wine or any other spirit into their blend.

Below are the standards:

1. Wholly produced at a licensed distillery in Scotland from water and grains, no substance can be added except endogenous enzyme and yeast.
2. Can be distilled by different stills, generally pot stills and continuous stills, at an alcoholic strength by volume of less than 94.8 percent.
3. Has been matured only in oak casks of a capacity not exceeding 700 litres; only in permitted place in Scotland for a period of not less than three years
4. Can be bottled with or without blending. No substance can be added except legalised colouring (plain caramel E105a) and water (for adjusting the alcoholic strength).
5. Has a minimum alcoholic strength by volume of 40%.
6. Must be bottled in Scotland before export. To export Scotch whisky in wooden casks is prohibited.
7. Labelling of whisky blended by spirits aged in different casks must reflect the age of the youngest whisky used. For example, you can only label ‘12 year old’ for a whisky that has used whiskies of 12, 20 and 40 year old. For single cask whisky, the label has to carry information such as distillation date, bottling date and cask number.