Whiskey which is also spelled whisky in Canada and Scotland is produced from fermented grain and aged in wood. Whiskey is manufactured in a place called distillery using a processing called fractional distillation. The equipment used in making whisky is called a still. Type of grain used (main differentiating factor), and the kind of formulas and processes are the differentiating factors for the various kind of whiskey available in the market today.

Processing of Whisky:

• The first step is the making of corn, rye, or barley into mash (soft mixture of cooked grain). This is done by cooking the grain or soaking it in hot water.
• Starch in the mash is then converted into sugar by adding malt.
• Yeast is added, changing the sugar into alcohol.
• It will produce liquid called wort, which has relatively low alcohol content. The wort is distilled, producing a liquid that is about 80% alcohol by volume. This liquid is diluted with water to reduce its alcoholic content to about 50%. It is then stored, or aged, for several years, usually in charred oak cask or barrels. The aging process adds color and flavor to whiskey.

Alcoholic content of whiskey: Strength of whiskey is measured in proof, most whiskeys range in strength from 80 to 110 proof. A 100-proof whiskey is 50% pure alcohol by volume and the other 50% consists of water and the impurities that provide color and flavor.

Kinds of Whiskey

• Straight whiskey is consisting entirely of one kind of whiskey.
• Blended whiskey is made by mixing two or more whiskeys of different ages, strengths, or flavors. In the USA blends, grain neutral spirits are also added, the spirits contain grain alcohol distilled at 190 proof. The spirits are not aged and therefore lack any distinctive flavor, color, or odor. Blended whiskey's production process permits distilleries to preserve quite a consistent flavor and mellower than single-malt whiskeys.

• Bonded whiskey is straight whiskey of at least 100 proof that has been aged in a government warehouse for at least four years and has been bottled under government supervision.
• Bourbon whiskey is a straight whiskey made from mash containing at least 51% corn. It is aged in charred oak casks for at least four years. In making sour-mash bourbon, fermentation is started with mash from a previous distilling, rather than with yeast. Bourbon is named for Bourbon Country, Kentucky, where it was first made.
• Rye whiskey is a straight whiskey made similarly to bourbon except that the mash is at least 51% rye.
• Corn whiskey is also a straight whiskey, it is made from mash that contains at least 80% corn.
• Scotch whisky is a blend of Scotch malted and Scotch grain whiskies. Scotch malted whisky is made from malted barley (barley that has begun to sprout). After the sprouts appear the barley is dried over a peat fire. Peat smoke gives Scotch its distinctive flavor. Scotch grain whisky is made from a mixed grain mash and is little more than grain alcohol. Scotch whisky is usually distilled twice and aged for at least three years.
• Irish whisky is usually made from a mixture of malted and unmalted barley and other grains. The malt is not exposed to peat (rotted plant material) smoke when it is dried. This type of whiskey need to undergo distillation thrice and then spend at least four years in oak cast before it can be considered drinkable. Because of its triple distillation and 4 years aging process, Irish whiskeys are famous for their smoothness and flavorful taste.
• Canadian whisky is made chiefly from rye and is aged in charred oak casks. It may be straight or blended.