Whisky aging process
Cask finish means 2nd aging in different cask for a few years or less after 1st aging for many years.
Cask finish purpose is adding specific flavor so normally cask for cask finish is rich flavor one like fortified wine cask and new oak wood cask.
Marriage means 2nd aging in cask after blending several whiskey and water.
Marriage purpose is familiarizing whiskies and water
Double marriage means twice marriage.
Double marriage purpose is creating complicated taste and flavor.
It's traditional style and normally soil floor and maximum 4 line stacks.
It's higher humidity due to soil floor and slower aging.
But storage space efficiency is very low.
It's 8-12 floor steal rack for storage. There are temperature difference between upper part and lower part due to height. Therefor cask on upper floor is faster aging than one on lower floor.
Cask is put vertically and it's normally for grain whisky.
Aging is fast but more leaking risk than others.
Storage efficiency is very high.