All American

Bourbon is the only uniquely American spirit. It can only be made in the United States. About 95% of bourbon is made in Kentucky, but it can legally be made in any state. Tennessee and Indiana vie for second place. Other significant producers are Virginia, Colorado, Ohio, California, Texas and New York. Bourbon can also be made in the District of Columbia and Puerto Rico. Other US territories are subject to debate, and the legality has not been formally established. However, Kentucky is king, and the biggest distilleries are located in the Bluegrass State.

Majority Corn Mash Bill

Bourbon’s mash bill must contain at least 51% corn. Any variety of corn can be used, but yellow dent corn is most often used. Some distilleries use heirloom varieties of corn. Bourbon can be 100% corn, but that is atypical. Usually, other grains are added for flavor or to convert the starches to sugars. Rye and wheat are the two most commonly used flavoring grains. Malted barley is most often used for its enzymatic properties, to break down the complex starches into simple sugars, which can be used for fermentation. Some distilleries have experimented with other flavoring grains, such as oats, rice, sorghum, millet and amaranth, among others. Some distilleries have used malted rye for its enzymatic properties. As long as the mash bill contains at least 51% corn, any combination of grains may be used.

Fermentation and Distillation

Bourbons may contain a variety of yeast strains, most of which are proprietary to the distillery. The yeast is what ferments the sugars into alcohol. The product, or distiller’s beer, is run through the still, which increases the alcohol content. A continuously operating column still may be used, particularly by large distilleries, or a smaller pot still may be used, particularly by craft distilleries, who want to achieve a more controlled flavor profile. The number of distillation runs may vary. Bad tasting congeners are removed from the alcohol. The final distillate is called new make or white dog. It may not come off the still at any higher than 160 proof.

Sour Mash vs. Sweet Mash

Sour mash means a portion of the last distillation run is placed back into the new batch for fermentation. The old mash adds flavor and consistency to the new mash. It also lowers the pH, which inhibits bacterial growth and allows the yeast to thrive. Sweet mash means everything in the new batch is new.

Aged In New, Charred Oak

Bourbon must be aged in a new, charred oak container. It does not have to be a barrel, though a barrel is the most efficient way to store the liquid. The level of char usually varies from a level 1 at 15 seconds to a level 4 at 55 seconds. Some distilleries use an even higher level of char. American oak is most commonly used, but the oak can be sourced from any country. A bourbon barrel can never be used to make bourbon again, though it can be used for finishing other alcoholic beverages, including bourbon itself. The distillate may not enter the container at any higher than 125 proof.

Duration of Aging

There is no minimum age requirement for bourbon. As long as the liquid hits a new, charred oak container, it can be called a bourbon. However, it would not be fit to drink. A straight bourbon must be aged for at least 2 years. If a bourbon is aged for less than 4 years, it must contain an age statement on the label. Bourbons with no age statement guarantee that the youngest liquid in the bottle is aged for at least 4 years. If an age statement is given, it refers to the youngest liquid in the bottle. Indeed, there may be older liquids in the bottle, as well.

Finishing

Bourbons can be finished in different barrels before bottling, but they must be labeled as such. They must meet all the requirements for bourbon before they are finished. Finished bourbons are aged for a shorter amount of time in different types of barrels, typically those used to age other types of liquor or wine. Some bourbons are finished in barrels that are toasted not charred, or in previously used bourbon barrels. Some bourbons are double barreled or double oaked. These are finished in a second new, charred oak barrel. Some distilleries place oak staves into the barrels for secondary finishing. Some distilleries move the barrels to exotic locations for secondary finishing.

Chill Filtration or Not

Chill filtration means the bourbon is filtered at a cooler temperature before bottling. This process removes many of the fatty acids and esters, which allows the bourbon to remain clear when served on ice. However, it also removes some of the flavor and the mouthfeel of the bourbon. Non-chill filtration means this step is omitted. The fatty acids and esters remain intact, which preserves the flavor and the mouthfeel.

Bottling

Nothing can be added to bourbon before bottling, except water. This is done to cut the bourbon down to bottling proof. A bourbon cannot be bottled at less than 80 proof. Many bourbons are bottled at barrel proof, or cask strength. This means no water is added at bottling. No artificial flavors or colors can be added to bourbon before bottling. All the flavors in bourbon come from the mash bill, the yeast strain, the water, the charred oak and the toast layer of the barrel. All the colors of bourbon come from the barrel. The higher the char level and the longer the aging process, the deeper the color will be. Obviously, finishing will change the flavor and the color of bourbon, but the liquid must be a bourbon before it is finished. This concept generates significant controversy among purists.

But Why Kentucky?

The reason most bourbon is made in Kentucky is because of the water. It is filtered through limestone aquifers, which removes bad tasting iron and adds good tasting calcium and magnesium. The other reason is historical. Corn was the main crop of Kentucky, when it was the frontier of Virginia. Early settlers from the Mid-Atlantic colonies were knowledgeable in whiskey making, especially rye whiskey. They easily adapted to making corn whiskey, which eventually became bourbon. This led to generations of whiskey makers, who built the major distilleries.

Single Barrel vs. Small Batch

Single barrel means the bourbon is bottled from a single barrel. It is not blended with other barrels. Therefore, single barrel bourbons of the same brand may vary significantly in proof and flavor from one another. Small batch means a small number of barrels are blended together to achieve a certain flavor profile. The number of barrels varies between distilleries, but the number is usually under 50. This is distinct from large batches, which may contain hundreds of barrels, and are designed to achieve a consistent flavor profile.

Bottled In Bond

Bottled-In-Bond means the bourbon must come from a single distillery in a single distilling season. It must be aged for at least 4 years, and it must be bottled at 100 proof. The barrels must be stored in a federally bonded warehouse. The rules were established by the Bottled-In-Bond Act of 1897, which is considered to be America’s first consumer protection act.

Straight Bourbons and Blends

Straight bourbons can only come from a single state. A blend of straight bourbons from the same state can still be called a straight bourbon. A blend of straight bourbons from different states must be labeled as a blend of straight bourbons.

Neat, On Ice, With Water Or Mixed

This one is up to you. It’s your bottle now. The distillery is no longer in the picture. You decide how to drink it. However, keep in mind that the distillery made this product so you could enjoy the flavors. They couldn’t alter the taste with additives, so you shouldn’t either. If you spent money on a high quality bourbon, drink it neat. Sip it slowly and savor the flavor. Adding a few drops of water helps to open up the bouquet without diluting the spirit. Kentucky limestone water is the best. If you prefer ice, use a clear ice cube or ice ball with no trapped air, made from filtered water. It will melt and dilute the spirit. This may be helpful with barrel proof bourbons. If you prefer cocktails, stick with spirit forward cocktails, like Old Fashioneds and Manhattans. Never mix a high quality bourbon with Coca-Cola.