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Cracking the Code: What are the 5 Keys of Bourbon?

bottles of bourbon as the banner

Last Updated on August 21, 2023 by Lydia Martin

As a bourbon lover, I’ve always been curious about what makes this iconic American whiskey unique and delicious.

After doing some research and sampling a few different varieties, I’ve discovered that five key elements are essential to creating a great bourbon.

But the question is: what are the 5 keys of bourbon? Come with me as we explore the fascinating bourbon community and the five keys club!

A Tribute: Blade and Bow

Blade and Bow is a premium bourbon brand that pays tribute to the art and craftsmanship of the historic Stitzel-Weller Distillery in Louisville, Kentucky. [1]

The brand was launched in 2015 by Diageo, a global leader in premium drinks, as a tribute to the distillery.

The Blade and Bow brand is labeled after the two portions of a skeleton key, the blade shaft and the fancy bow.

These keys represented the brand’s commitment to honoring the past and unlocking the potential of the future.

The Blade and Bow Bourbon take pride in the rich heritage and the traditional five brass keys to bourbon making, especially their Kentucky Straight Bourbon Whiskey.

The five Blade and Bow keys represent the mash bill, water, yeast, distillation, and aging, which were originally established by the legendary Stitzel-Weller Distillery in the 1930s.

pretty girl holding a glass of bourbon sitting on top of a barrel

The Five Keys of Bourbon

Key #1: Mash Bill

How does the mash bill affect the flavor of bourbon?

The mash bill, or the combination of grains used in the production of Kentucky bourbon, affects the flavor of bourbon in several ways:

  • Sweetness: The proportion of corn in the mash bill can influence the sweetness of the bourbon, with higher corn percentages resulting in a sweeter taste.
  • Spiciness: The proportion of rye in the mash bill can contribute to the spiciness of the bourbon. Higher rye percentages result in a spicier flavor profile.
  • Complexity: The use of different grains in the mash bill, such as wheat or malted barley, can contribute to the complexity of the bourbon’s flavor.
  • Roasting or toasting: The degree of roasting or toasting of the grains used in the mash bill can also affect the flavor profile of the bourbon. Longer roasting times can result in more intense and complex flavors.
  • Aging: The mash bill can also influence how the bourbon ages in the barrel. Different mash bills require different aging times to reach their optimal flavor.

a hearty meal paired with a glass of bourbon on the rocks

Key #2: Water

How does the water source affect the flavor of bourbon?

The characteristics of the water used in bourbon production can significantly impact the final product’s taste, aroma, and texture.

Here are some of the key characteristics of the water used in bourbon production:

  • Mineral Content: The mineral content of the water can affect the flavor of the bourbon. Water with a higher mineral content, such as that sourced from limestone-rich areas like Kentucky, can impart unique flavor characteristics to the bourbon.
  • pH Level: The pH level of the water source can impact the acidity and sweetness of the bourbon. Water with a neutral pH level can provide balance to the bourbon and enhance the overall flavor.
  • Geographic Location: The geographic location of the water source can affect the flavor of the bourbon. Water sourced from different regions can have different mineral compositions and flavor profiles, which can impact the final product.
  • Impurities: The presence of impurities like chlorine and other contaminants can negatively impact the flavor of the bourbon. Using high-quality, pure water is essential to ensure the final product has a clean and consistent flavor profile.
  • Water Treatment: The treatment process used on the water source can affect the flavor of the bourbon. Water sources may need to be treated to remove any impurities or adjust the mineral content, which can impact the flavor of the bourbon.

Key #3: Yeast

How does the yeast strain used to affect the flavor of bourbon?

Understanding the impact of yeast strain on the flavor of bourbon is crucial, and here are the key points that highlight its influence:

  • Flavor profile: Different yeast strains produce different flavors, and each strain can impart unique characteristics to the bourbon. For example, some strains produce fruity notes like banana or pear, while others produce spicy or floral notes. Distillers carefully select specific yeast strains to achieve the desired flavor profile of their bourbon.
  • Fermentation time and temperature: The yeast strain used in bourbon production can affect the fermentation time and temperature, which can also impact the flavor of the bourbon. Some yeast strains work faster or slower than others, and some produce more heat during fermentation, which can affect the final flavor.
  • Congeners: Yeast also has compounds called congeners, which can contribute to the flavor of bourbon. Congeners are created during fermentation and can include flavors like vanilla, caramel, and butterscotch. The type and amount of congeners produced vary depending on the yeast strain.
  • Consistency: Using a consistent yeast strain can help ensure that each batch of bourbon has a similar flavor profile. Distillers often work to create a consistent flavor profile for their bourbon, and using the same yeast strain can be an important factor in achieving that consistency.
  • Maturation: While yeast strain primarily affects the flavor of the bourbon during fermentation, it can also have an impact on the final product after maturation. Some yeast strains may create more or less stable compounds over time, which can affect the flavor of the bourbon as it ages in barrels.

Key #4: Distillation

How does the distillation process affect the flavor of bourbon?

The distillation process plays a significant role in determining the flavor profile of bourbon, and here are a few key ways it can impact the final product [2]:

  • The concentration of flavor: As the liquid is heated and vaporized, the flavors become concentrated, resulting in a more robust and complex flavor profile.
  • Removal of impurities: The distillation process removes impurities such as fusel oils, which can contribute to off-flavors and harshness in the final product.
  • Chemical reactions: During distillation, chemical reactions can impact the flavor of the bourbon. For example, the Maillard reaction, which occurs when amino acids and sugars combine, can create flavors such as caramel and toffee.
  • Copper contact: Many stills are made of copper, which can react with the bourbon and help remove sulfur compounds and other unwanted flavors.
  • Cut points: The distiller’s choice of “cut points,” or when to start and stop collecting the distillate, can impact the flavor. For example, taking the “heads” too far into the heart of the distillate can result in off-flavors and harshness.

Key #5: Aging

How do different types of barrels affect the flavor of bourbon?

Different types of barrels can significantly impact the flavor of bourbon during aging. Here are some ways in which this can occur:

  • Oak species: The species of oak used in the barrel can influence the flavor of the bourbon. American white oak is the most commonly used type of oak for bourbon barrels due to its favorable flavor profile.
  • Toasting and charring levels: The degree of toasting and charring of the barrel can affect the flavor of the bourbon. Light toasting will produce lighter and sweeter flavors, while heavy charring will produce stronger and smokier flavors.
  • Age of the barrel: The age of the barrel can also influence the flavor of the bourbon. New barrels will contribute more oak flavors and tannins, while used barrels will have less of these flavors and may impart flavors from their previous contents.
  • Size of the barrel: The size of the barrel can affect the flavor of the bourbon as well. Smaller barrels provide more surface area contact between the whiskey and the wood, leading to faster maturation and more intense flavors. Larger barrels provide a slower maturation process and milder flavors.



What are the main characteristics of bourbon?

The main characteristics of bourbon include being a type of American whiskey made from a mash bill of at least 51% corn, aged in new, charred oak barrels, distilled to no more than 80% ABV, barreled at no more than 62.5% ABV, and bottled at a minimum of 40% ABV.

Additionally, bourbon must be produced in the United States, and it is typically known for its sweet, smooth, and oaky flavor profile, with notes of vanilla, caramel, and spice.





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