In 1908, a couple of years before distilling became impossible in Tennessee due to pre-Volstead prohibition reaching all corners in the state, a chemist studied the famous maple leaching system for Tennessee whiskey, also called the Lincoln County Process.
The study is here, by William Dudley, published in the Journal of the American Chemical Society.
The Cascade Distillery is referenced specifically so the data mentioned clearly relates to that distillery.
This was located in Cascade Hollow in Tennessee and was about one mile from where the George Dickel Distillery is (now) located, its successor after a winding path.
Some salient points:
– the maple charcoal vats, whose dimensions are precisely described, were designed to hold 80 bushels of maple charcoal and could leach 80 barrels of whiskey – thus one barrel needed one bushel of charcoal for the desired effect. About three barrels were produced each per day
– the vats were replaced “frequently”, but a more precise interval is not stated. Today at George Dickel, I’ve read in this authority it is about 12 months;
– the analysts found the taste of leached and unleached white dog very different. I’ve tasted the “before and after” of Jack Daniels and found them fairly similar
– he felt that all fatty oils soaked into the charcoal and acids were notably reduced as well, which alteration also meant the whiskey aged differently once put into regular charred barrels for storage (which it was, he makes this clear)
– the way “Bourbon whiskey” is referred to, it seems no bourbon the analyst was familiar with was subjected to a similar process: to him the maple charcoal mellowing system was peculiar to Tennessee
– some bourbon and rye mash whiskey was subjected to a “before and after” test similar to the one done for Cascade’s whiskey. This was done to all appearances in the lab using a scaled-down maple charcoal tube the scientist had fashioned. From what I can tell the only “production” white whiskey compared before and after was from Cascade Distillery.
There is other interesting data which only a full reading of the article can convey.
I have read latterly hundreds of pages in 19th century and early 1900s sources on Kentucky whiskies in trade papers, science texts, and druggists’ literature. I never found a reference to any brand of Kentucky whiskey so treated.
To be sure, there are vague general statements that at one time more distillers used the method, but it seems in other words to have been associated only with Tennessee at least after the Civil War.
In Tennessee, apart from Cascade, Jack Daniels used it – still does – and a distillery called R.H. Cate did, in Knoxville, TN. There were probably others, bearing in mind as prohibition advanced across Tennessee in the late 1800s that there was only a handful of producing distilleries there by 1900. Kentucky still had hundreds.
To be sure distillers outside Tennessee had used the method latterly but it is referred to in this regard as a “highwines” method. Distillers who made neutral alcohol would leach their low wines (the first run) in the vats and then re-distill it to neutral alcohol territory. Charcoal vat leaching is never referred to as something a Kentucky sweet mash or sour mash distiller would do – not that I have found.
I am starting to think, unless any evidence to the contrary pops up, that it may really have been a Tennessee strategy to help genuine whiskey (not highwines) on its way to early maturity. As to why Kentucky wasn’t using it in the period mentioned, hard to say. Many accounts of prized double-distilled whiskey in the Bluegrass refer to its body and even to being “heavy”. Perhaps the Kentucky connoisseurs didn’t like the lightness of body the Lincoln County Process imparts. There is no question both Dickel and Daniels today are genuine whiskey, but most whiskey hands would aver that they have a relative lightness of body compared to Kentucky bourbon. The maple vats achieve this.