The Big Chill

The next to last step before bottling Bourbon is chill filtering, which removes certain compounds that settle out at low temperatures. These compounds don’t spoil the flavor at all (Booker’s is an example of a Bourbon that isn’t chill-filtered), but the process is done because some drinkers object to the hazy look that unfiltered whiskey gets on ice.

Marscha Wiechman is in charge of chill filtering at the tiny bottling plant--it looks like the proverbial red schoolhouse--of Blanton’s, the pioneer single-barrel Bourbon. She rolls in the barrels on an overhead rack, then pulls the bungs with a tool that resembles a dent puller from an auto body shop.

“We used to start the bungs with a bung mallet, the same kind you use for pounding them in in the first place,� she says, showing a wooden mallet with a long, flat head, “by pounding on alternate sides of it until it pops out. We stopped, though, because [the other workers] complained of the noise.�

When a barrel has been dumped, the whiskey is chilled for two or three hours so the haze can be filtered out. Finally Wiechman calculates the alcohol content and adds water to bring the proof down to standard for bottling.

The tiny Blanton’s operation uses old dairy farm milk chillers for the chilling.

“They’ve enticed them with stronger cooling coils so they’ll go down lower, down to 15 degrees,� says Wiechman.

Though the temperature is below the freezing point for water, the whiskey remains liquid because of its alcohol content.

Wiechman, who’s worked for Leestown Distillers for 13 years, got her job through a newspaper ad. “I worked in the warehouse for the first year, rolling barrels,� she says. “The work isn’t all so pleasant as this.� Particularly not in summer, when the upper floors of a warehouse get up to 120 degrees.

She opens a chiller and sniffs the rich, complex caramel aroma. “To me,� she says, “chilling’s what really shows the flavor of Bourbon, what it’s all about. I love my job.�