The elimination of some congeners by the filtration of whisky which has been previously chilled to a temperature more or less close to 0° C. It improves the clarity and prevents hazing at low temperatures (Which has strictly no consequence) at the price of the loss of some aromatic components.

cold filtering of the distil that allows to remove from the distil the greater part of congeners.

Whiskey is often chilled before bottling to remove congeners which would otherwise cause hazing if the whiskey were stored at low temperatures.