Today, we wade into a lesser-known part of the definition of Bourbon, which also means it’s a bit less controversial.
First, as a bit of a refresher, recall that the legal definition of bourbon whisky, according to the TTB, is:
Whisky produced in the U.S. at not exceeding 80% alcohol by volume (160 proof) from a fermented mash of not less than 51 percent corn and stored at not more than 62.5% alcohol by volume (125 proof) in charred new oak containers.
The phrase “Alcohol by Volume” (ABV), when associated with a percentage, is quite literally what it sounds like: the measure of the content of ethanol (alcohol) in an alcoholic beverage by volume. It is required by the Code of Federal Regulations for distilled spirits labels to include the ABV on the front of the bottle.
The term “proof”, while not required on spirits labels, is often included, particularly when it comes to whisk(e)y. The history of the term dates back to the 16th century and involves gun powder, taxes, and rum – a fun history indeed, but something for another blog post! The easiest way to understand proof in the United States is simply twice the ABV of an alcoholic beverage. So, a 100 proof whisky has an ABV of 50%.
This part of the definition has to do with the ABV/proof of the spirit as it comes off the still. Distillers are able to change the conditions in the still to control the ABV/proof during distillation, including the amount of heat applied to the mash, the amount of plates the alcohol vapor comes in contact with, or the amount of cooling water in the condensers that will cause reflux and re-distillation, just to name a few. The mandate here is to keep the spirit coming off of the still at or below 80% alcohol or 160 proof.
The question one could ask is: why limit this?
The answer: Taste and aroma.
The process of distillation is really a process of volume loss. To offer a rough example, we take 500 gallons of 6% mash/wash, distill it up to 45% ABV and between the heads cut, tails cut, and what’s left behind in the still, we lose most of our volume, yielding approximately 80 gallons of spirit. We’ll then distill that a second time to a higher ABV and lose even more volume. Essentially, we’re pulling the alcohol out into higher and higher concentrations, leaving behind water, grain, and yeast.
In this process, we’re not only leaving behind water, but flavor compounds, congeners, and impurities.
By definition, vodka must be distilled up to or exceeding 190 proof or 95% alcohol. The process of distilling something to 190 proof will theoretically leave it “odorless and tasteless”. The alcohol was concentrated and water and compounds were left out.
So, by requiring Bourbon to be distilled at or below 80% alcohol or 160 proof, more flavor is maintained. Now, we can’t say that maintaining flavor is the reason the Federal Government mandated this limit, but what they were trying to do was create a recognizable, familiar type and class so consumers could understand what they’re getting in a bottle. By mandating a maximum proof at distillation, the hope is that bourbon whisky produced in this manner will then have the “taste, aroma and characteristics generally attributed to” this type of whisky.
If you want to experience this phenomenon in person, stop in to the distillery and taste the difference between our unaged Corn Whisky, distilled to only 152 proof, and our vodka, distilled to 191 proof. While the mash bills (recipes) are different, you’ll still begin to understand the difference “proof at distillation” has on a spirit. The Corn Whisky has loads of flavor, even a bit of bite, while the Vodka flavors are much more soft and subtle.
At Long Road, our experienced team of distillers takes great care in crafting a unique product with robust flavors in a consistent manner. We’re proud of the fact that we worked with Vendome Copper and Brass, arguably the best whisk(e)y still manufacturers in the world (not many people will argue this fact), to create a custom 500 gallon copper pot still that allows us to handcraft our bourbon both precision and a touch of artistry. And, we’re eager for you to taste the difference when you Take the Long Road!
Stay tuned for Parts 3 & 4 of “What is Bourbon?” coming over the next few weeks!