Tennessee whiskey is different from Bourbon because they filter the new make whiskey through the “Lincoln County Process”. This “Process” is a tall vat of sugar maple charcoal that filters out some of the vegetable oils and other compounds and “mellows” the whiskey before entering the new make into a charred barrel. It is called the “Lincoln County Process” because legend has that it was invented in Lincoln County, Tennessee in the 1830s. Is this true? Well maybe yes, but maybe no.
Filtering whiskey though charcoal is a process that pre-dates the Lincoln County process. The Beale-Booth Family Papers at the Filson Historical Society contains a document that describes how to make a filter to improve whiskey. It calls for a vat with a false bottom with many holes drilled into it and a drain pipe under the bottom. Above the false bottom you layer sugar maple charcoal, gravel and wool blankets to filler the vat. You then filter your whiskey through this vat before using it to mellow out the roughness of the new make. This document dates to the late 18th century or very early 19th century. This is your basic charcoal mellowing vat but on a smaller scale than what is being used at Jack Daniels or George Dickel to mellow their whiskey. It can be argued that this is not the Lincoln County Process, but it is definitely a forerunner of the process being used today.
It is also documented that a similar process was being used in Canada to make their whiskey in the early 19th century. The vats I have seen described in Canada were larger than those described in the Beale-Booth Papers, but it is unclear as to how much larger. The Canadians were filtering their whiskey for the same reason as described in the Beale-Booth Papers, to take the rough edges out of the new make spirit. However both processes, from Beale-Booth and in Canada, were done before aging the whiskey became a common process. It was done to make the unaged whiskey more palatable to those drinking unaged whiskey.
It can be argued, and I tend to believe this argument, that the Lincoln County Process was created to jump-start the aging process by exposing the whiskey to the charred wood and in order to do this they needed the larger vats used at the big Tennessee distilleries today. These vats are very large with a height over ten feet. It takes a long time for the whiskey to work its way through the charcoal and in comparison to the process described in Beale-Booth, there is going to be even more influence from the wood. The George Dickel Distillery has gone an extra step in the process. Because Dickel believed that the best whiskey was made in the winter, they now use cooling coils to keep the charcoal vat temperature in the 40 degree range.
The Lincoln County Process does make the whiskey different from Bourbon. It gives the whiskey more of a smoky flavor and it has less of a creamy mouth-feel. I do believe that the Lincoln County Process was probably developed in Tennessee in the 1830s and that it is different from simply charcoal filtering the whiskey before entering it into the barrel. Tennessee whiskey is its own unique style because of the Lincoln County Process.
Photos Courtesy of Unsplash and Maggie Kimberl