So What is Whiskey...
So what makes whiskey...whiskey? That is a complex AND simple answer. We are going to go with a resonably short basic explanation. This may or may not be more than you want to know but just in case here goes.
Whiskey is a spirit that is produced by distilling 100% fermented grain mash (most commonly, corn, wheat, barley (malted) and rye), put into an oak container for storage and aging, distilled below 180 proof and bottled at a minimum of 80 proof.
The first listed record comes from Ireland around 1405. Now in the general categories of Whiskey (Whisky) you have: Bourbon, Irish Whiskey, Scotch, Japanese, Tennessee and Canadian. If the country of Origin has a "E" in the name it is usually spelled Whiskey (with an "e") If the country does not have an "E" it is usually listed as Whisky (No "E"). Although the spelling may be different it is still essentially the same. Most of it is pretty damn good! but to give you the basic differences let's start below (trust there are more details, this is a basic overview).
Bourbon
Must be produced in the U.S.
Made from at least 51% corn
Distilled at 160 proof or below
Put into a NEW charred oak container
Have no added substances other than water
Kentucky Bourbon - must be produces and aged for at least 1 year in the State of Kentucky
Straight Bourbon - must be aged at least 2 years. If it is aged less than 4 years, it has to have an age statement on the label.
Tennessee Whiskey
Tennessee All the same guidelines as Bourbon but made in Tenessee AND goes through what is known as the Lincoln County Process. It is a filtering system that takes the alcohol through maple wood charcoal before it goes into the barrel. BTW - Jack Daniels Whiskey does not say Bourbon anywhere on that bottle. Don't loose a bet! Even if you have been drinking a little bit...or a lot!
Irish Whiskey
Must be made in Ireland
Is made from cereal grains
Is fermented by yeast
Distilled to max of 189.6
Aged in Ireland in wooden casks for at least 3 years
In addition you have Malt Irish Whiskey, Pot Still Irish Whiskey, Grain Irish Whiskey, and Blended Irish Whiskey. These all differ mostly by the type of still they utilize.
Scotch
Produced in Scotland (Production is usually in the regions of Islay, Speyside, Lowlands, Highlands and Cambeltown)
Made from Malted Barley (and possibly other cereal grains) and uses the barley for the natural sugar/enzyme conversion
Put in Oak Casks and aged for at least 3 years
Contains no other substances other than caramel coloring
Under this category you also have single malt, single grain, blended malt, blended grain and blended scotch. With Scotch production the malt is usually smoked with burning peat. That smokiness influences the flavor. Also most Scotch is put into used barrels as opposed to new ones.
Japanese Whiskey
Pretty much follows Scotch methods but has no legal definition
Canadian
Produced in Canada
Made from Cereal Grains
Aged in Canada in a Wooden barrels for at least 3 years
Flavoring and Coloring may be added
Now these are the basics...there are a lot more details to it. BTW - Moonshine is also in the Whiskey category - who knew? If you would like to learn more, please do so. I have listed some good reading sources for you. Grab a drink and get down to it...if the lines start getting blurry, put down the book/tablet/phone. Finish your drink and read some more the next day!
The Ultimate Book of Whiskey by Joe Clark & Stuart Derrick
Big Whiskey by Carlo Devito
Know it All Whiskey Editor Charles MacLean/Foreward Ian Buxton
The Bourbon Bartender by Jane Danger & Alla Lapushchik