Whiskey came to America with the Irish and Scottish immigrants.
As they settled in their new homeland, they were forced to adapt in many ways including the use of new raw materials. Gradually through the years a new kind of whiskey evolved.
Today there are few, if any, similarities left between American whiskey and its whiskey cousins from Scotland and Ireland. For example, smoke is not used to dry the corn, rye or wheat used in American whiskey. Because of this, American whiskey often has a fuller, stronger and sweeter taste than its European counterparts.
American whiskey is commonly divided into six categories: Bourbon, Tennessee, Rye, Wheat, Corn and Blended whiskey. The categories are mainly motivated by differences in the type and amount of grains used during the mashing but there are also differences such as aging.
Because almost all Bourbon is made in Kentucky, many people believe this is a requirement, but in fact, Bourbon may be produced in any state. The only prerequisites are that it must be made in the US, contain at least 51 percent corn and be stored for at least two years in new, charred oak barrels. (Jim Beam, Van Winkle, Buffalo Trace, Eagle Rare, Blanton’s, Maker’s Mark, Woodford Reserve, Evan Williams, Elijah Craig, Wild Turkey)
Tennessee whiskey is closely related to Bourbon but there are a few differences. Tennessee whiskey must be produced in the state of Tennessee and is always filtered through sugar-maple charcoal. The filtering process usually takes 10 days to complete. (Jack Daniel’s, George Dickel Whiskey)
Rye and Wheat Whiskey
Only a small amount of Rye whisky is bottled as Straight Rye Whisky—most of it’s used in blending to add character to other whiskies. To be called a Rye whiskey, the spirit must be made from at least 51 percent rye and aged in charred oak barrels for at least two years. Rye whiskey is slightly more powerful and bitter than Bourbon. Most current Rye whiskies are made in Indiana and Kentucky. Wheat whiskey must be made from at least 51 percent wheat and is quite uncommon. (Wild Turkey Straight Rye Whiskey, Van Winkle Family Reserve Rye 13 Year, Sazerac Rye Whiskey 18 yr)
Corn whiskey was developed due to the abundant supply of corn and is a predecessor to Bourbon. As the name suggests, corn is the main ingredient. The mash must consist of at least 80 percent corn. Another difference between corn whiskey and Bourbon is that corn whiskey does not have to be aged in wood. If corn whiskey is to be aged, any maturation must be done in either un-charred barrels or used Bourbon barrels.
Blended American Whiskey
The blended American whiskey should not be confused with the blended Scottish whisky. Blended American whiskey only contains 20 percent of Rye and Bourbon whiskey; the remaining 80 percent are made up of a neutral spirit. American Blended whiskey is much lighter than Tennessee and Bourbon whiskies.