Bourbon Aging
Bourbon = Produced in the United States grain mixture that is at least 51% corn. distilled to no more than 160 (U.S.) proof (80% alcohol by volume). aged in new, charred oak barrels.
Bourbon = Produced in the United States grain mixture that is at least 51% corn. distilled to no more than 160 (U.S.) proof (80% alcohol by volume). aged in new, charred oak barrels.
Scotch = technically whisky (spelled without the “e”) that has been distilled and matured in Scotland

Neutral spirit types of alcohol need filtering and are most often produced in a continuous still. The purpose of a pot still is to bring the flavors over to the resulting liquid. Any flavoring to neutral spirits is is infused in a "Gin Box" right before the steamed vapor is condensed, or it is added (infused) to already distilled spirits.
Filtering only for pure spirits that are typically distilled several times, that are typically distilled in a continuous still with many bubble plates.
