It just so happens my father, brother and I celebrate our birthdays all within the same month, and to celebrate this year, we headed to Louisville, Kentucky, for the bourbon and craft whiskey trails. Firsthand research went into this article—barrels of research.

bourbon vs. whiskey
All bourbon is whiskey, but not all whiskey is bourbon. Whiskey can be made anywhere in the world, the most famous being Ireland, Scotland, Canada, and even Japan. U.S. regulations state that whiskey can be distilled from any combination of grains and produced at no more than 190 proof. It must be aged in oak barrels and bottled at no less that 80 proof.

Bourbon must be made from at least 51 percent corn and produced in the U.S. at no more than 160 proof. It must enter the barrel at no more than 125 proof. It must be aged in newly charred oak barrels. ‘Straight Bourbon’ refers to the product being aged at least two years in oak. Most bourbon in the market has been aged four or more years. Most bourbons (95 percent) are produced in Kentucky, given the unique quality of limestone-rich and iron-free spring water in the area surrounding Lexington and Louisville.

single-barrel whiskey
Barrels matter in whiskey making. Much like single vineyards and vintage in wine production, how long and where the barrel is located in the rick house, as well as the batch of distillate that goes into the individual barrel, all play a role in the finished product. Barrels located in a higher location in the rick house tend to be more concentrated due to the exposure to higher temperatures.

cask strength
Before whiskey is bottled, it typically is diluted to proof by adding water. A cask-strength whiskey is one that has not been diluted but instead goes into the bottle unadulterated at the proof it comes out of the barrel. This varies from barrel to barrel, but it’s definitely higher in alcohol, usually between 110 and 115 proof. Feel the burn? Good stuff.

bourbon of choice
» Willett Family Estate Rare Release 3 Year Single Barrel Straight Rye: I was fortunate to score the last available bottle: Barrel #230, bottle #198, 115.8 proof. Consequently, two prosciutto hams were hanging and aging in one of the Willett rick houses. A local chef was experimentally rick house-aging his house-made prosciutto—we need to find out when and where that tasting will be!
» Four Roses Single Barrel HW-15-1M: We enjoyed a private tour behind the scenes, as well as an upgraded private tasting. I picked this one to bring home: 100 proof.
» Yellowstone Limited edition Kentucky Straight Bourbon: Distilled by Steve and Paul Beam, seventh-generation distillers, at Limestone Branch: dark, rich amber with dried fig, cinnamon, caramel, vanilla and toast. This was Dad’s gift from my brother and me … My grandfather used to drink this bourbon prior to production being interrupted. 105 years later …
» Kentucky Knows Bourbon Ball Barrel Coffee: Bourbon barrel artist Tony Davis ages coffee in freshly spent Buffalo Trace bourbon barrels. The coffee picks up the aromatics and flavors from the whiskey-laced wood and is amazing. You can definitely smell and taste the nuances of the bourbon.

Jeffrey Hall is the sommelier for The Four Seasons Hotel-St. Louis.