Denny Potter (pictured below), the Master Distiller of Maker’s Mark, talked about the rules behind making bourbon on the film ‘Neat: The Story of Bourbon’ released in 2018. On this blog post I have described what Denny shared with us on the documentary. Note that at the time of filming he was working for Heaven Hill Distillers.

For those of you with Netflix, the documentary is available there and it “dives into the rich and storied world of bourbon, exploring its colourful history, charismatic characters, and uniquely American process – the film is a celebration of the time, artistry, and relationships that make America’s only native spirit.”

The rules as Denny puts it in the film, are described as the ABC’s of Bourbon.

Interestingly, early whiskey was shipped downriver in barrels stencilled with the name ‘Old Bourbon’ to designate the former name of the area they were from, as people grew to like corn whiskey, the name stuck…the rest as they say, is history (source including picture below: Whisky Exchange).

source: Whisky Exchange

The ABC’s of Bourbon

A is for ‘American Made’ 

By Act of the United States Congress, bourbon whiskey can be produced anywhere in the United States and it does not have to be made exclusively in the state of Kentucky.

However most of the bourbon produced – around 95% of the total – come from Kentucky due in part to the strong historical association with the region.



B is for ‘Barrels’

Bourbon must be made with new charred oak barrels.

The ‘white dog’ produced (in effect, what we would call new make spirit in Scotland) has to be placed into newly charred American white oak barrels for ageing as part of the maturation process.

Bourbons will gain their colour and some of their flavour due to the interaction with the wood from the barrel. However this can vary as bourbon has no minimum ageing period. The United States federal regulations make no mention of how long a bourbon must be aged, and some bourbons are aged for as little as three months.




C is for ‘Corn’

A minimum of 51% of the mash bill for producing bourbon has to be made up of corn. The remainder can be made up of rye, malted barley and/or wheat.

Yeast is added for the mash to be fermented, before it is distilled.

The sweetness of bourbon typically comes from corn whilst the other cereal grains provide complexity and different characteristics, such as the mouthfeel which rye can provide.




D is for ‘Distillation Proof’

The resulting distillate coming off the still, the so called white dog, cannot have a higher alcohol content than 160 proof or legs (80% abv).

White dog goes by a few different names: white lightning, light whiskey, white whiskey.





E is for ‘Entry Proof’

The alcohol (white dog) entering the barrel must have no more than 125 proof or legs (62.5% abv).

For bourbon to be designated “straight bourbon whiskey” it must have aged in new charred oak barrels for a period of at least two years.



F is for ‘Fill Proof’

Bourbon once out of the barrels, must be filled (or bottled) at 80 proof or higher (40% abv or higher).

Bourbon classified as Bottled In Bond must have been made during a single distilled season at one distillery, aged in a federally bonded warehouse for a period of at least four years and bottled at 100 proof as originally defined in the Bottled-in-Bond Act of 1897. Only American whiskeys can carry the label of “Bottled in Bond” and any such bourbon label must identify the distillery from which it was distilled and bottled.



G is for ‘Genuine’


Bourbon cannot have any additives added and therefore no additional flavourings or colourings can be added.

To be a genuine bourbon, the liquid has to be 100% natural.

Bourbon that has an age stated on its label must be labelled with the age of the youngest whiskey in the bottle.

Note that bourbon labelled as ‘blended’ may contain added colouring, flavouring and other spirits (e.g. un-aged neutral grain spirits) but it has to contain at least 51% straight bourbon whiskey.



For more information about the rules and regulations of bourbon, visit the Alcohol and Tobacco Tax and Trade Bureau.

Picture below from the American Bourbon Association.


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