Generally in production of distilled alcohol beverages the primary aim is to receive high quality, clean and tasty distillate, in which major role has material and construction of distillation pot. It is also is very important to find and keep correct balance of aromatic essential oils - named congeners. This ones determine the uniq flavor and bouquet of future whiskey.
Distillation pot for receiving whiskey must be able to clean fermented wash from all bed admixtures, heavy molecules, such as short and long chain fuzzy oils, acid oils, aldethyds, methanol, acetone…which was dangerous for human health. At the same time it has to keep normal quantities of aromatic esters in spirit.
Otherwise the Whiskey necessarily needs further filtration - the result of which is loosing not only impurities, but also essential flavors that makes organoleptic characteristics poor.
Only in such case is it possible to create hight quality, clean distillate with good aromatic parameters which is useful for future aging.