Bourbon Day

What the day is

Bourbon Day is observed on June 14, marking a whiskey defined almost entirely by regulation rather than by tradition.

Origin and background

The legal requirements are unusually specific. Bourbon must be made in the United States from a grain mixture that is at least 51 percent corn, distilled below a set strength, and aged in new charred oak containers. Nothing may be added except water, so there is no coloring and no flavoring, and whiskey labeled straight bourbon has spent at least two years in the barrel.

It does not have to come from Kentucky. That is probably the most widespread myth about it. The overwhelming majority is made there, but the law asks only for the United States.

The new-oak requirement has a consequence that reaches around the world. A bourbon barrel may be used only once for bourbon, which leaves the industry with an enormous surplus of barrels that are perfectly sound and now carry bourbon in the wood. They are sold on, and a great deal of Scotch whisky, Irish whiskey, rum and tequila is matured in second-hand American bourbon barrels. A rule written to protect one product ended up shaping the taste of several others.

Nearly everything people taste in bourbon comes from that barrel. Charring the inside breaks the wood down and caramelizes sugars within it, and the spirit moves into and out of the wood as the warehouse heats and cools across the year, which is why temperature swings matter and why age by itself is a poor guide to quality.

The barrel takes its cut as well. A percentage of the contents evaporates every year, traditionally called the angel's share, and over a long maturation the loss is considerable.

Gin, covered in the June 13 entry, needs no aging whatsoever, which is precisely the opposite economic problem.

How to take part

• Read the label for the word straight, which tells you a minimum age.
• Add a few drops of water and notice how much it opens up.
• Look up where a favorite Scotch got its barrels.
• Taste the char. Most of what you are tasting is wood rather than grain.