Ever since I became involved with the bourbon industry, I’ve noticed there are many misperceptions out there about the spirit. Perhaps the biggest misconception is where it is made. Contrary to popular believe, bourbon does not have to be made in the state of Kentucky, but it does have to be made in the United States.

Our social media channels are teaming with heated debates on this topic, so I wanted to set the record straight and share the facts of exactly what makes bourbon bourbon, and how that differs from other whiskeys from around the world.

Remember this: All bourbon is whiskey, but not all whiskey is bourbon.

The U.S. Congress first recognized bourbon whiskey as a “distinctive product of the United States” in 1964 and outlined the rules of the spirit.

All whiskeys have rules of production, which I will discuss here. So let’s go ahead and start with bourbon.

Rule #1: Bourbon must be made in the United States.

As I mentioned above, bourbon does not have to be made in Kentucky, although 95% of it is. It can be made in any state in America, and there are bourbons being produced in all 50 states.

Rule #2: Bourbon must be made using at least 51% corn.

Most bourbons use corn, malted barley and either rye or wheat in their recipes, but no matter what grains they use, the mash bill must contain at least 51% corn. Corn grows well in America, hence the predominant ingredient in the mash bill.

Rule #3: Bourbon must be aged in new, charred oak containers.

This is an important one, because unlike other whiskeys (as I will discuss in a bit), bourbon must be aged in a brand new barrel or cask.

Rule #4: Bourbon must not be distilled higher than 160 proof.

When making whiskey in general, it’s important not to distill it too high, because the flavors of the grains can get stripped out at higher proofs. Vodka, for example, is usually distilled at 180 or higher, which is also why it is an odorless and flavorless spirit.

Anything distilled above 160 proof usually removes most of the intricate flavors that make bourbon so tasty.

Rule #5: Bourbon must not be put into a barrel higher than 125 proof.

I’ve heard that barrel entry proof is important in distilling, and different companies use different numbers. The average range of entry proof is anywhere between 110-125, so distillers must decide if they want to add more water at the beginning to proof down the distillate, or at the end after the bourbon has aged.

It’s more cost-efficient to add the water after the bourbon has aged, because you won’t have to purchase as many barrels. However, some believe that proofing it down before you enter it into a barrel helps the water and alcohol mingle more cohesively, thus producing a better-tasting, well-balanced bourbon.

Rule #6: Bourbon must be bottled at 80 proof or higher.

Like all other whiskeys, bourbon must be bottled at 80 proof or higher. If it’s below that, it falls into the liqueur category.

Rule #7: Bourbon cannot contain added coloring or flavors.

100% of bourbon’s color comes from aging inside the charred oak barrel. That’s it. You cannot add caramel coloring or any kind of flavoring to the bourbon period.

These are the rules of bourbon, and you might have noticed there isn’t any mention of aging. That’s because bourbon technically does not have to be aged, but it’s not going to taste very good if you don’t let it mingle with the barrel at least a couple of years.

If you’re the label reads “straight bourbon,” this just means it’s been aged for a minimum of two years. If it’s less than 4 years old, there must be an age statement on the label.

Other Whiskeys by Definition

So how does bourbon compare to other whiskeys around the world? Here’s a quick reference.

Rules for Scotch whisky:

• Produced in Scotland
• Made from malted barley and other grains
• Aged in Scotland in oak casks for at least three years
• Contains no added substance other than caramel coloring

As you can see, Scotch whisky does not have to be aged in new casks, and it can include caramel coloring, which bourbon definitely cannot. There are, of course, many other differences between bourbon and scotch, but the main ones are its use of malted barley as the main grain component and the fact that that barley is often smoked/dried using peat. 

Rules for Irish whiskey:

• Produced in Ireland
• Made from cereal grains
• Distilled at no more than 190 proof
• Aged in Ireland in wooden casks for at least three years
• Cannot use any flavoring or coloring

Ireland can use all sorts of grains for its whiskey, which makes it quite unique in the category. It also doesn’t have to use new oak casks or barrels.

Rules for Canadian whisky:

• Produced in Canada
• Distilled at no more than 190 proof
• Aged in Canada in wooden barrels for at least three years

Canadian whisky is probably the most open categories under the “whiskey” umbrella, because it can use both coloring and flavoring. It also does not require using a new barrel.

It’s worth noting another whiskey category: Japanese whisky. Its rules are also quite open (for now) and sometimes include blending Japan-made distillate with other products from outside the country, sometimes even Scotch. This category is constantly changing, and new rules have been proposed by the Japan Spirits & Liqueurs Makers Association.

New rules for Japanese whisky:

• Must use malted grains (and may include other cereal grains)
• Water must be extracted in Japan
• Fermentation and distillation must take place at a Japanese distillery
• Must be aged in wooded casks in Japan for at least three years
• Must be bottled in Japan
• Caramel coloring can be used