Science Uncovers the Secrets of Tennessee Whiskey

Jack Daniel's Tennessee whiskey is one of many made using the famed Lincoln County Process, which takes its name from the area where Jack Daniel's was first made. (Credit: monticello/shutterstock) Champagne is only champagne if it’s made in its namesake region in France, Scotch is exclusively distilled and matured in Scotland, and a “bourbon” label is reserved for products from the United States. And there’s one variation on the bourbon recipe — Tennessee Whiskey — that’s made exclusively in, well, Tennessee. You might be familiar with its largest maker, Jack Daniels. But Tennessee whiskey isn’t just bourbon distilled across a state line. (95 percent of bourbon comes from neighboring Kentucky.) To make it, distillers put their whiskey through an extra step, called the Lincoln County Process, named for the location of the original Jack Daniel’s distillery. This process “charcoal mellows” the whiskey, filtering the spirit through charred wood, usually sugar maple. The idea is that this removes impurities and “smooths” the flavors — it doesn’t add anything. Tennessee distillers each have their own way of doing it; many even make their own charcoal in-house. But what actually happens during this LCP step? As food scientists at the University of Tennessee are finding out, it’s more than you might think.