Great Rivers Imaging

Bourbon must be aged in new, charred oak barrels. It’s a critical step in developing bourbon’s distinct flavor.Freshly distilled bourbon doesn’t look anything like what you use to make an Old Fashioned.

When it comes out of the still, it’s crystal clear, and smells and tastes like funky raw grain. Most of a bourbon’s character, and all of its color, come from the cask itself.

As the bourbon ages in the barrel, it soaks up flavor, aroma, and pigment from the oak. All barrels used to age beverages are heat-treated in some way, since raw wood has an unpleasantly green and sappy flavor. Wine barrels are usually toasted, while bourbon barrels are always charred, giving them a sweet, smoky tinge.

You can think of casks a little bit like tea bags. They’ll always impart the most flavor on their first use. You can use them a second, third, or even fourth time, but with every use, they lose a little bit of their flavoring power.

Bourbon regulations require the use of brand-new barrels each and every time, which means bourbon usually has a robustly oak-driven flavor profile. Key oak flavor attributes are vanilla, baking spice, caramel, and coconut.

Most bourbon is aged in barrels made from American white oak, but any type of oak is allowed. What’s definitely not allowed is re-using those barrels to age more bourbon.

That’s not to say those barrels don’t get reused at all. Distillers around the world rely on Kentucky bourbon distillers and their seemingly endless stream of once-used barrels as a reliable source for casks to age Scotch whisky, Irish whiskey, rum, and aged tequila. There’s still plenty of oomph left in those casks to age other spirits–just not enough to create that unmistakably oak-driven character of American bourbon.

Click on the photo for mor information. Click here to see all photos from the Kentucky Bourbon Trail