Unraveling the secrets of Tennessee whiskey

Carried out John P. Munafo, Jr., assistant professor of taste science and pure merchandise, and his graduate pupil, Trenton Kerley, the research “Adjustments in Tennessee Whiskey Odorants by the Lincoln County Course of” was just lately printed within the Journal of Agricultural and Meals Chemistry (JAFC).

The research included a mix of superior taste chemistry methods to probe the modifications in taste chemistry occurring throughout charcoal filtration. The sort of filtration is a standard step within the manufacturing of distilled drinks, together with vodka and rum, nevertheless it’s a required step for a product to be labeled “Tennessee whiskey.” The step known as the Lincoln County Course of (LCP), after the locale of the unique Jack Daniel’s distillery. It is usually known as “charcoal mellowing.”

The LCP step is carried out by passing the contemporary whiskey distillate by means of a mattress of charcoal, normally derived from burnt sugar maple, previous to barrel-aging the product. Though no scientific research have proved such a declare, it’s believed that the LCP imparts a “smoother” taste to Tennessee whiskey. As well as, by legislation for the excellence of getting “Tennessee whiskey” on the label, the liquor have to be produced within the state of Tennessee from at the very least 51% corn after having been aged in Tennessee for at the very least 2 years in unused charred oak barrels.

The precise LCP differs from distiller to distiller, and, as the main points are usually held as a commerce secret, the method has been traditionally shrouded in thriller. There aren’t any rules as to how the method is carried out, solely that the step is required. In different phrases, all a producer must do is move the distillate over charcoal (an undefined quantity — presumably even only one piece). Thus, relying on the way it’s performed, the LCP step might not affect the whisky taste in any respect. Alternatively, even small changes to the LCP can modify the flavour profile of the whiskey positively or negatively, probably inflicting any variety of surprises.

Munafo and Kerley describe how distillers alter parameters empirically all through the whiskey manufacturing course of, then depend on skilled tasters to pattern merchandise, mixing subtly distinctive batches to realize their goal taste. Munafo says, “By gaining a elementary understanding of the modifications in taste chemistry occurring throughout whiskey manufacturing, our crew might advise distillers about precisely what modifications are wanted to make their course of produce their desired taste targets. We need to give distillers levers to tug, so they aren’t randomly or blindly making an attempt to get the exact taste they need.”

Samples used within the research had been supplied by the Sugarlands Distilling Firm (SDC), in Gatlinburg, Tennessee, producers of the Roaming Man Whiskey. SDC invited the UTIA researchers to go to their distillery and acquire in-process samples. Munafo says SDC prioritizes transparency round their craft and takes delight in sharing the analysis, discovery and distillation means of how their whiskey is made and what makes Tennessee whiskey distinctive.

Olfactory evaluations — the nice ole scent take a look at — revealed that the LCP therapy usually decreased malty, rancid, fatty and roasty aromas within the whiskey distillates. As for the odorants (i.e., molecules accountable for odor), 49 had been recognized within the distillate samples utilizing an analytical method known as fuel chromatography-olfactometry (GC-O). 9 of those odorants have by no means been reported within the scientific whiskey literature.

One of many newly discovered whiskey odorants, known as DMPF, was initially found in cocoa. It’s described as having a singular anise or citrus-like scent. One other of the newly found whiskey odorants (known as MND) is described as having a nice dried hay-like aroma. Each odorants have remarkably low odor thresholds within the parts-per-trillion vary, that means that the smells might be detected at very low ranges by folks however are troublesome to detect with scientific instrumentation.

The one earlier investigation into how charcoal therapy impacts whiskey was printed in 1908 by William Dudley within the Journal of the American Chemical Society. The brand new research revealed contemporary data for optimizing Tennessee whiskey manufacturing. Thirty-one whiskey odorants had been measured by way of a method known as secure isotope dilution assay (SIDA), all exhibiting a lower in focus on account of LCP therapy, albeit to totally different levels. That’s to say, whereas the LCP seems to be selective in eradicating sure odorants, the method did not enhance or add any odorants to the distillate. This new data can be utilized to optimize Tennessee whiskey manufacturing. As an illustration, the method might be optimized for the removing of undesirable aromas, whereas sustaining increased ranges of fascinating aromas, thus “tailoring” the flavour profile of the completed whiskey.

“We need to present the analytical instruments wanted to assist allow distillers to have extra management of their processes and make extra constant and flavorful whiskey, says Dr. Munafo. “We need to assist them to take out a number of the guesswork concerned in whiskey manufacturing.”

Further research at the moment are underway on the UT Division of Meals Science to characterize each the flavour chemistry of various kinds of whiskey and their manufacturing processes. The last word purpose of the whiskey taste chemistry program is to help whiskey producers in producing a constant product with the precise taste profile that they need. Even with the help of science Munafo says, “Whiskey making will ‘nonetheless’ stay a formidable artwork kind.” Pun supposed.

The researchers acknowledge assist from the USDA Nationwide Institute of Meals and Agriculture (NIFA) Hatch Mission #1015002 and funding by means of the Meals Science Division and start-up funding from the College of Tennessee Institute of Agriculture.