The Lincoln County Process is a step used in producing almost all Tennessee whiskeys. The whiskey is filtered through—or steeped in—charcoal chips before going into the casks for aging. The process is named for Lincoln County, Tennessee, which was the location of Jack Daniel's distillery at the time of its establishment, but is no longer used in that county (where the only remaining distilleries are Benjamin Prichard's and Southern Pride Distillery). Methods Nearly every distillery creating Tennessee whisky uses maple charcoal filtering, though the actual process for accomplishing this varies by company. For Jack Daniel's, the charcoal used is created onsite from stacks (ricks) of two-by-two-inch sugar maple timbers. The timbers are primed with 140 proof Jack Daniel's and then ignited under large hoods to prevent sparks. Once they reach the char state, the ricks are sprayed with water to prevent complete combustion. The resulting charcoal is then fed through a grinder to produce bean-size pellets that are packed into vats used to filter impurities from the 140 proof whiskey. The whiskey is then reduced with water to 125 proof for aging. The process was taught to Jack Daniel by Nearest Green, the namesake of Uncle Nearest Premium Whiskey. The George Dickel distillery uses deeper () vats and distills the whisky—the spelling used by Dickel—to 135 proof. Dickel chills its whisky to before it enters the vats and allows the liquid to fill the vats instead of trickling it through. Nelson's Green Brier Distillery uses the Lincoln County Process to make its wheated First 108 Tennessee whiskey and its white whiskey. Collier and McKeel, made in Nashville, uses a method that pumps the whiskey slowly through feet of sugar maple charcoal (instead of using gravity) made from trees cut by local sawmills. Legal considerations To be labeled as a straight whiskey, no flavoring or coloring compounds can be added to the spirit after the fermenting of the grain. Some producers claim that according to a 1941 Internal Revenue Service ruling issued at the request of Jack Daniel Distillery, the Lincoln County Process is what distinguishes "Tennessee whiskey" from "bourbon". However, not all producers of products labeled as Tennessee whiskey use the process. (Specifically, it is not used in the production of Benjamin Prichard's Tennessee Whiskey.) The term "Tennessee whiskey" does not actually have a legal definition in the U.S. Federal regulations that define the Standards of Identity for Distilled Spirits.