Here is Tennessee’s current laws on moonshine.

Moonshine had been considered illegal in most part of Tennessee before 2010 when it was legal in only 3 counties. But, since 2010 it is legal in 44 counties provided that the manufacturer holds a license issued by the state (the Tennessee Code 2010 39-17-706).The first moonshine distillery license was granted in 2010 to Ole Smoky Moonshine Distillery. Unlicensed production of moonshine is considered to be a Class A misdemeanour.
Possession of still or any other apparatus for distilling moonshine is considered to be a Class B misdemeanour (The Tennessee Code 2010 39-17-707).
Distillation of moonshine in homes is not allowed without a license which subjects you to tax, but manufacture of un-distilled liquor up to 5 gallons is allowed in Tennessee provided that it is used for domestic use only (The Tennessee Code 39-17-708).

What are the steps for acquiring Moonshine Production license in Tennessee?
In order to be eligible for producing moonshine, the manufacturer has to obtain a distillery license. This can be done by filling out Distillery Application Form (Form AB-0034), Questionnaire (Form AB-0009) and by getting the site of production approved by the state. A $300 application fee (non-redundable) fee and an annual $1000 fee will also be charged. A TTB Distilled Spirit plant and a TTB Basic Permit is also required to fulfil federal laws.

If I was to distill a product for home use only, I would have to have a license and pay $1300.

*** It is however legal to have a still to use for distilling essential oils and for the purification of water***